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%'y  (<ti.1  •  a  AY  8       :i.914 


Aerials 

LAWES  AGRICULTURAL  TRUST 


Rothamsted  Experimental  Station, 
Harpenden. 


Annual  Report  for  1913 


with  the 


Supplement 

to  the 

"Guide  to  the  Experimental  Plots" 

containing 

The  Yields  per  Acre,  etc. 


In  every  case  the  page,  table,  and  plot  numbers  refer  to  the  "Guide"  1913,  it  being 
understood  that  no  change  is  made  in  the  manuring,  etc.,  there  described. 


E.  J.  RUSSELL,  D.Sc,  Director. 

/ 

f  8 

HARPENDEN: 


Printed  by  D.  J.  Jeffery,  Vaug 
1914. 


HAN    ROAD, 

1 


Laboratory  Staff. 


Director 


E.  J.  Russell,  D.Sc. 


Lawes  and  Gilbert  Laboratory. 

N.  H.  J.  Miller,  Ph.D., 

F.I.C. 
...  E.  H.  Richards,  B.Sc, 
F.I.C. 
Board  of  Agriculture  Research  Scholar  W.  Buddin,  B.A. 

„                   „               „         J.  A.  Prescott,  B.Sc. 
Voluntary  Research  Worker H.  Sonnenfeld,  M.S.Agr. 


Chemist  ... 

Hon. Rupert  Guinness  Chemist 


Chemical  and  General  Assistant 


.  E.  Grey. 
.  A.  Oggelsby. 
.  A.  Bowden. 
.  B.  Weston. 


James  Mason  Bacteriological  Laboratory. 


Bacteriologist 

Carnegie  Research  Scholar 

Protozoologist    ... 

Assistant 


.  H.  B.  Hutchinson,  Ph.D. 

.  K.  MacLennan,  B.Sc. 

.  K.  R.  Lewin,  B.A. 

..  P.  Wilson. 


Soil  Laboratory. 

Goldsmiths'  Company's  Chemist          ...   E.  Horton,  B.Sc. 
,,                    „            Physicist        ...   B.  A.  Keen,  B.Sc. 
Chemist  for  Gas  Investigations            ...   A.  Appleyard,  M.Sc. 
Board  of  Agriculture  Research  Scholar  E.  J.  Holmyard,  B.A. 
Carnegie  Research  Scholar      W.  Weir,  M.A.,  B.Sc. 


Organic  Laboratory. 


Chemist  ... 
Assistant  Chemist 


Botanist  ... 

Assistant  Botanist 
Assistant 


Wr.  A.  Davis,  B.Sc,  A.C.G.I. 
A.  J.  Daish,  B.Sc,  A.C.G.I. 
G.  C.  Sawyer. 


Botanical  Laboratory. 


Winifred  E.  Brenchley, 

D.Sc,  F.L.S. 
Helen  Adam,  B.Sc. 
Grace  Bassil. 


Manager  .. 


The  Farm 

S.  J.  K.  Eames. 


Secretary 

1        ite  Secretary 

Clerk       

Junior  Clerk 

General  Assistant  and  Caretaker 
General  Assistant 
Laboratory  1 1 


,.  G.  T.   DUNKLKY. 

.  <  rERTRUDE    BATES. 

,.  W.  Wilson. 

.  C.  Pearce. 

.  W.  Pearce. 

,.  G.  Lavvki  \<  i  . 

.  W.  ( rAME  AND  I '.  SEABROOK. 


3 

INTRODUCTION 


John  Bennet  Lawes  was  the  founder  of  the  Rothamsted 
Experimental  Station.  He  began  experiments  with  various 
manurial  substances,  first  with  plants  in  pots  and  then  in  the  field, 
soon  after  entering  into  possession  of  the  estate  at  Rothamsted  in 
1834.  In  1843  more  systematic  field  experiments  were  begun,  and 
the  services  of  Joseph  Henry  Gilbert  were  obtained  as  Director, 
thus  starting  the  long  association  which  only  terminated  with  the 
death  of  Lawes  in  1900,  followed  by  that  of  Gilbert  in  1901. 

The  Rothamsted  Experimental  Station  has  never  been  connected 
with  any  external  organisation,  but  has  been  maintained  entirely  at 
the  cost  of  the  late  Sir  John  Lawes.  In  1889  he  constituted  a  Trust 
for  the  continuance  of  the  investigations,  setting  apart  for  that  pur- 
pose the  Laboratory  (which  had  been  built  by  public  subscription, 
and  presented  to  him  in  1855)  certain  areas  of  land  on  which  the 
experimental  plots  were  situated,  and  ^"100,000. 

By  the  provision  of  the  Trust  Deed  the  management  is 
entrusted  to  a  Committee  nominated  by  the  Royal  Society  (four 
persons),  the  Royal  Agricultural  Society  (two  persons),  the  Chemical 
and  Linnean  Societies  (one  each),  and  the  owner  of  Rothamsted. 

Mr.  A.  D.  Hall  was  appointed  Director  in  1902  and  held  the 
position  till  he  resigned  in  1912,  when  the  present  Director,  Dr. 
E.  J.  Russell,  was  appointed.  He  brought  about  great  developments, 
re-organising  the  work,  increasing  the  staff,  and  considerably  extend- 
ing the  buildings  and  laboratories.  In  1906  Mr.  J.  F.  Mason,  M.P., 
presented  the  Committee  with  ,£"1,000  f°r  the  building  and  equip- 
ment of  the  "James  Mason"  Bacteriological  Laboratory,  together 
with  a  grant  towards  its  maintenance.  In  1907  the  Goldsmiths' 
Company  made  a  grant  of  £  10,000,  the  income  of  which  is  devoted 
exclusively  to  the  investigation  of  the  soil.  The  Permanent  Nitrate 
Committee  have  also  made  a  grant  of  ^"2,000  to  the  endowment. 
The  Society  for  extending  the  Rothamsted  Experiments,  founded 
in  1904,  collects  donations  and  annual  subscriptions  to  help  carry  on 
the  work. 

During  the  year  1911  a  scheme  was  published  from  the  Board 
of  x\griculture  for  the  encouragement  of  agricultural  research  with 
funds  provided  by  the  Development  Commission,  and  this  scheme 
established  or  assisted  a  certain  number  of  institutes  for  fundamental 
research,  each  dealing  with  one  great  branch  of  the  subject.  The 
Rothamsted  Experimental  Station  is  recognised  as  the  Institute 
for  dealing  with  Soil  and  Plant  Nutrition  Problems.  In  accordance 
with  this  scheme  a  grant  of  £'2,500  was  made  for  the  current  year, 
and  it  is  expected  that  an  annual  grant  of  this  amount  will  be  made 
to  the  Station  in  future.  Certain  scholarships  have  also  been 
instituted  to  provide  the  training  in  research  work  for  men  who  have 
already  qualified  in  pure  science  and  are  desirous  of  taking  up  an 
agricultural  career.  The  holders  of  three  of  these  scholarships  are 
now  doing  their  work  at  Rothamsted.  In  addition,  investigators  from 
other  institutions  periodically  spend  a  certain  amount  of  time  in  the 
laboratories  studying  analytical  methods  or  ways  of  getting  over 
difficulties  that  have  arisen  in  the  course  of  their  work. 

These  developments  have  necessitated  a  considerable  extension 


of  the  laboratory  and  of  the  farm.  For  this  purpose  a  grant  of 
^3,100  was  given  by  the  Board  of  Agriculture  out  of  the  Develop- 
ment Fund,  and  an  equal  sum  was  provided  by  the  Society  for 
Extending  the  Rothamsted  Experiments.  In  1911,  230  acres 
of  land  were  taken  on  a  77  years'  lease,  and  this,  together  with 
the  Trust  land,  gave  a  self-contained  farm  capable  of  being  worked 
with  great  advantage  to  the  experiments.  A  new  wing  of  the 
Laboratory  was  opened  on  June  27,  1913,  by  the  Rt.  Hon.  Walter 
Runciman,  M.P.,  President  of  the  Hoard  of  Agriculture. 

The  condition  of  the  main  laboratory,  however,  gives  cause  for 
considerable  anxiety.  It  was  built  in  1855  and  some  years  ago 
began  to  reveal  certain  structural  defects.  The  Committee  are 
advised  that  it  may  not  last  much  longer,  and  steps  have  been  taken 
to  raise  the  sum  of  ^"12,000  for  the  erection  of  a  laboratory  suited 
to  modern  requirements.  The  opening  of  this  laboratory  is  to 
commemorate  the  centenary  of  the  birth  of  Sir  J.  B.  Lawes  in 
1814  and  of  Sir  J.  H.  Gilbert  in  1817. 

The  field  experiments,  which  began  in  1843,  have  on  some  of 
the  plots  been  continued  without  break  or  alteration  up  to  the 
present  day  ;  on  the  Broadbalk  Wheat  Field  certain  rearrangements 
were  made  in  1852,  in  which  year  also  the  Barley  experiments  on 
the  Hoos  Field  began.  The  leguminous  crops  on  the  Hoos  Field 
were  started  in  1848,  the  experiments  on  Roots  have  been  continued 
on  the  same  field  since  1843,  and  on  the  same  plan  since  1856.  The 
grass  plots  began  in  1856,  and  the  rotation  experiments  in  1848. 

It  is  impossible  to  exaggerate  the  importance  of  continuing  the 
experimental  plots  at  Rothamsted  without  any  change,  as  nowhere 
else  in  the  world  do  such  extensive  data  exist  for  studying  the  effect 
of  season  and  manuring  upon  the  yield  and  quality  of  the  crop,  and 
for  watching  the  progressive  changes  which  are  going  on  in  the  soil. 
Year  by  year  these  plots  are  found  to  throw  light  upon  new  problems 
in  Agricultural  Science ;  in  all  directions  they  continue  to  provide 
material  for  investigations  upon  points  which  were  not  contemplated 
in  the  original  design  of  the  experiments,  so  that  it  is  impossible  to 
foresee  when  and  how  they  will  not  become  useful  and  provide 
indispensable  material  for  the  solution  of  problems  undreamt  of  at 
the  present  time. 

The  maintenance,  however,  of  the  old  data  throws  a  heavy 
burden  on  the  Experimental  Station.  There  are  210  plots,  and 
every  year  243  samples  have  to  be  taken  with  proper  precautions 
and  put  into  store  for  future  reference.  In  addition,  many  analytical 
determinations  are  made.  During  the  present  and  the  coming  season 
complete  soil  samples  are  being  taken  for  analysis,  to  enable  a  com- 
parison to  be  instituted  with  the  set  of  samples  taken  in  1894,  and 
thus  to  study  the  soil  changes  that  have  gone  on  during  the  last 
twenty  years.      A  complete  botanical  analysis  of  the  grass  plots  is 

n  hand. 

It  should  be  remembered  that  the  object  of  the  Rothamsted 
Experiments  in  t<>  study  the  soil  and  the  crop,  and  only  indirectly  to 
find  tint  most  paying  method  of  manuring;  hence  neither  the  nature 
nor  the  quantities  of  material  applied  are  to  be  taken  as  indicating 
the  manures  winch  should  be  used  in  practice. 


ANNUAL  REPORT 

FOR  THE  YEAR   1913 


THE  distinguishing  features  of  1913  were  its  sunless,  rainy 
spring  and  its  dry,  sunless  summer.  The  temperature  was, 
on  the  whole,  somewhat  above  the  average  excepting  in  July, 
when  it  was  distinctly  lower.  There  were  many  more  wet  days  in 
January,  March  and  April  than  usual,  and  at  the  end  of  the  latter 
month  we  had  had  no  less  than  10  inches  of  rain  instead  of  the  nor- 
mal 7'9.  June,  July,  August  and  September  were,  however,  very 
dry ;  October  and  November  had  the  average  rain  fall,  but  Decem- 
ber was  considerably  drier  than  usual.  For  the  whole  year  the 
rainfall  was  2472  inches,  this  being  3*62  inches  or  12*8  per  cent, 
below  the  average.  This  deficit  was  characteristic  of  much  of  the 
Eastern  part  of  England,  although,  as  Dr.  Mill  has  pointed  out,  there 
was  approximately  an  equal  excess  over  much  of  the  West.  The 
number  of  hours  of  bright  sunshine  was  1337,  being  255  less  than 
the  average.  The  deficit  arose  during  the  four  months,  January  to 
April,  and  the  three  months  July  to  September,  particularly  during 
July  when  we  had  93  hours  only  instead  of  the  average  218. 

From  the  farmer's  standpoint  the  October  of  1912  had  been 
favourable  but  November  had  been  wet,  so  that  work  was  delayed 
and  a  smaller  area  of  winter  corn  was  sown  than  was  intended. 
December  was  fine,  however,  and  the  wheat  and  winter  oats  made 
a  good  start.  The  land  was  very  wet  at  the  end  of  December,  but 
on  the  whole,  the  conditions  were  good  till  the  middle  of  March,  so 
that  all  the  spring  corn  went  in  well.  Then  the  persistent  wetness 
and  the  increasing  excess  of  rainfall  began  to  tell,  and  work  on  the 
potato  land  was  brought  to  a  standstill,  and  instead  of  getting  in  the 
crop  early  in  April,  we  had  to  wait  to  the  third  week  in  May.  The 
sowing  of  mangolds  was  similarly  delayed  and  it  was  May  30th 
before  Barnfield  was  sown.  This  field,  which  has  carried  root  crops 
with  only  a  three-year  break  since  1843,  is  somewhat  difficult  to 
manage  in  spring :  it  tends  to  become  suddenly  hard  on  top  while 
underneath  it  is  still  too  spongy  to  carry  the  horses.  In  con- 
sequence, the  season  for  getting  in  the  seed  is  easily  missed.  Even 
the  dunged  plots  show  this  behaviour  to  some  extent,  though  not  so 
markedly  as  those  receiving  no  organic  manure.  The  farm  mangolds 
could  not  be  sown  till  June  9th  and  did  very  badly.  The  swedes  on 
Little  Hoos  field  went  in  well  and  came  up  well,  but  a  large  pro- 
portion of  the  plant  died  because  no  rain  fell :  more  seed  was  sown 
on  July  16th  but  the  crop  failed.  A  fair  crop  of  hay  was  secured  : 
it  was  given  four  clear  days  to  make  and  went  into  the  stack  well, 
showing  no  tendency  to  become  heated  like  a  good  deal  of  hay  in 
the  district  that  had  been  hurried  in  too  quickly. 

The  harvest  came  early  and  the  weather  was  exceedingly  good. 
Winter  oats  and  wheat  yielded  well,  spring  oats  wrere  rather  below, 
but  barley  was  above  the  average. 

In  the  experiment  plots,  the  outstanding  feature  of  the  year  was 
the  extraordinarily  large  crop  of  barley  in  Hoos  Field.  Right  from 
the  outset  the  plants  grew7  remarkably  well  and  they  wTent  through 
to  the  end  without  a  check.  The  plots  without  potash  tended  to 
become  laid  :  those  supplied  with  nitrogen  tended  to  form  their  ears 


more  rapidly  than  those  which  received  no  nitrogen  :  while  the  plots 
receiving  phosphates  began  as  usual  to  ripen  earlier  than  the  others. 
In  all  cases  the  crops  were  very  uniform  over  the  whole  plot,  and  the 
irregularities  which  showed  in  1911  on  plot  2A  vanished  entirely. 
Several  of  the  plots  yielded  over  60  bushels  of  grain,  30  cwt.  of 
straw  and  7,000  lb.  of  total  produce  per  acre  :  to  find  any  parallel  we 
have  to  go  back  nearly  60  years.  The  season  was  of  course  very 
favourable  for  barley  :  the  spring  being  moist  and  the  summer  cool 
and  dry.  But  there  was  another  circumstance  which  appears  to  have 
contributed  to  the  high  yield.  For  60  years  in  succession,  barley 
crops  have  been  grown  continuously  in  Hoos  Field  without  any  break, 
but  recently  weeds  had  accumulated  to  such  an  extent  that  after  the 
harvest  of  1911  it  was  decided  to  fallow  the  field  for  a  year,  cul- 
tivating thoroughly  to  keep  the  land  free  from  all  growth  during 
the  season,  and,  of  course,  withholding  all  manure.  The  fallow 
ended  in  March,  1913. 

There  can  be  little  doubt  that  the  fallow  played  a  considerable 
part  in  bringing  about  the  high  yield.  It  is  difficult  to  account 
for  the  result  on  our  present  views  as  to  the  effects  of  fallowing : 
something  more  seems  to  be  involved  than  the  accumulation  of 
nitrate  over  the  winter.  Laboratory  work,  discussed  later  on,  in- 
dicates the  existence  of  another  factor :  an  apparent  effect  of  a 
growing  crop  on  bacterial  decompositions  in  the  soil  which  is  not 
exerted  during  the  fallow  period.  The  important  problems  thus 
opened  up  are  under  further  investigation. 

Another  very  important  problem  is  raised  by  these  results.  The 
yield — 60  bushels  of  grain  and  30  cwt.  of  straw — is  extraordinarily 
high  for  us,  and  has  been  obtained  only  three  times  before,  viz., 
1854,  1857  and,  in  Agdell  Field  only,  in  1861.  It  seems  to  represent 
the  utmost  our  soil  can  do.  There  is  remarkably  little  variation 
between  the  best  plots  this  year,  seven  of  them  varying  only  within 
4  bushels,  viz.,  from  60  to  64,  and  the  variation  does  not  become 
much  wider  if  one  includes  the  three  early  years  and  the  Rotation 
experiments  as  well  as  the  continuous  crop.  This  result  is  readily 
explained  on  physiological  grounds:  of  the  various  plant  require- 
ments, all  must  be  satisfied,  or  growth  will  not  continue.  If  any 
one  is  withheld,  it  sets  a  limit  beyond  which  crop  growth  will  not 
take  place.  Lack  of  food,  water,  temperature  may  all  constitute 
limiting  factors,  any  of  which  would  prevent  the  crop  from  rising 
indefinitely.  The  fact  that  our  crop  has  not  yet  been  pushed  beyond 
64  bushels  during  the  60  years  of  experiment  shows  that  some 
limiting  factor  is  at  work  which  is  not  overcome  by  any  of  the 
manurial  combinations  or  cultivation  methods  we  use. 

The  limit  may  be  set  by  the  sheer  inability  of  the  plant  to  grow 
any  larger,  in  which  case,  the  plant  breeder  could  come  to  the  rescue 
by  producing  more  vigorously  growing  varieties.  But  this  was  not 
the  case  here.  Sixty-four  bushels  of  barley  is  by  no  means  a  record 
crop  on  good  barley  soils,  and  probably  many  farmers  have  obtained 
more.  The  limit  in  our  case  seems  to  be  set  by  the  soil  type;  ours 
is  not  a  good  barley  soil,  i.e.,  it  is  not  perfectly  adapted  to  barley, 
and  no  mere  addition  of  food  stuffs  will  make  it  so. 

The  barley  on  the  Agdell  Rotation  Field  did  not  yield  anything 
like  as  heavily  as  on  the  Hoos  continuous  plots,  the  highest  crop 
being  33  bushels  of   grain,  15   cwt.  of  straw,   and  3,500  lb.  of  total 


produce  ;  these  figures  are  far  short  of  what  has  been  obtained  from 
the  same  plots  in  certain  previous  years.  The  difference  is  presum- 
ably the  result  of  the  fallow  in  Hoos  Field,  for  all  other  conditions 
were  the  same  in  both  cases :  this  view  is  strengthened  by  the  fact 
that  the  unmanured  plot  on  Agdell  (which  had  virtually  been  fallowed 
during  the  preceding  year,  the  turnip  crop  having  failed)  gave  18*5 
bushels  of  grain  and  8  cwt.  of  straw,  nearly  the  same  yield  as  the 
unmanured  Hoos  Field  plot,  21  bushels  of  grain  and  10  cwt.  of 
straw.  Only  where  the  turnip  crop  had  grown  in  1912  were  the 
yields  markedly  less  than  on  Hoos  Field. 

An  interesting  result  was  obtained  on  the  two  unmanured  plots 
in  Agdell  Field.  On  one  of  these  the  rotation  is  dead  fallow,  wheat, 
swedes,  barley  ;  on  the  other  it  is  clover,  wheat,  swedes,  barley.  On 
the  manured  plots  the  clover  brings  about  an  increase  in  the  wheat, 
but  on  the  unmanured  plot  it  usually  exerts  a  depressing  effect, 
both  on  the  wheat  and  the  barley.  This  year,  however,  the  result 
was  different;  an  increased  crop  was  obtained  on  the  unmanured 
barley  plot  as  well  as  on  the  manured  plots  as  a  result  of  growing 
clover.  The  method  of  getting  in  the  clover  is  to  sow  it  broadcast 
among  the  barley  as  soon  as  the  barley  is  up :  in  some  way,  the 
barley  this  year  has  benefited  from  the  clover  sown  along  with  it. 

The  wheat  on  the  Broadbalk  plots  gave  much  better  yields  than 
last  year  in  consequence  of  there  being  less  Alopecurits  agrestis.  The 
plots  are  still  far  from  being  clean,  however,  and  only  the  yields  of  the 
lower  cleaner  half  of  the  field  are  given  in  the  Table.  The  variety 
grown  is  the  Square  Head's  Master,  which  is  well  adapted  to  our 
conditions.  At  a  width  of  7f  inches  apart  33  rows  were  sown  per 
plot ::,:  during  the  period  1906 — 1912  the  rows  had  been  set  12  inches 
apart  to  facilitate  hand  hoeing:  there  were  then  19  to  20  rows  per 
plot  in  alternate  years.  As  in  the  case  of  the  barley,  nitrogenous 
manures  were  found  to  hasten  the  formation  of  ear,  plots  receiving 
such  manures  being  distinctly  earlier  than  the  rest  in  heading  out. 
None  of  the  yields  were  large  :  28  bushels  was  the  highest :  this  was 
only  secured  on  the  most  heavily  manured  plot.  These  yields  are  below 
the  average  on  Broadbalk.  On  the  surrounding  fields  36  bushels 
were  obtained,  but  even  this  is  not  exceptionally  high:  we  have  twice 
on  Broadbalk — in  1863  and  1864 — had  as  much  as  50  bushels;  in- 
deed, in  1863  we  got  56  bushels  of  grain  and  10,000  lb.  total 
produce.  On  the  Agdell  Rotation  Fields,  however,  the  crops  have 
never  been  as  large.  These  results  are  wholly  exceptional,  and 
represent  the  combined  effect  of  high  manuring,  good  cultivation  and 
an  unusually  good  season.  In  normal  years  our  most  intense  scheme 
of  manuring  yields  only  40  to  45  bushels.  Again  the  soil  type  seems 
to  be  the  limiting  factor,  and  the  lesson  may  be  drawn  that  the  best 
cultivation  and  manuring  is  ineffective  to  push  yields  up  beyond  a 
certain  limit  set  by  the  season  and  the  soil  type.  One  might  try  to 
push  this  limit  higher  and  this  is  being  done,  but  a  no  less  useful  line 
of  experiment  is  to  try  and  secure  these  same  yields  at  lower  cost. 


*One  afterwards  had  to  be  hoed  up,  leaving  32  per  plot. 


THE  LABORATORY  AND  POT  CULTURE  HOUSE. 

The  fundamental  problem  before  the  Rothamsted  workers  is 
to  study  the  mutual  relationships  of  the  soil  and  the  plant.  For 
convenience  of  working  the  problem  is  divided  into  two  parts  :  the 
investigation  of  the  factors  that  make  for  greater  and  more  vigorous 
growth  on  the  part  of  the  plant,  and  the  study  of  the  factors  that 
bring  about  changes  in  the  plant,  particularly  those  associated  with 
"quality." 

At  least  six  soil  factors  are  now  known  to  be  concerned 
in  plant  growth  :  a  proper  supply  of  plant  food ;  of  water ;  of  air 
for  the  roots ;  sufficient  temperature ;  adequate  root  room  ;  and  the 
absence  of  harmful  and  injurious  factors.  In  order  to  limit  the 
problem,  the  work  is  at  present  confined  to  one  of  these,  which, 
however,  is  often  the  most  important  in  British  agriculture;  the 
supply  of  nitrogenous  plant  food.  Our  researches  are  directed  to  the 
elucidation  of  the  chemical  reactions  involved  in  the  production  of 
nitrates  in  the  soil,  the  agents  bringing  about  the  changes,  and  the 
influence  on  the  whole  process  of  soil  and  plant  conditions. 

It  has  long  been  known  that  the  complex  nitrogen  compounds 
contained  in  farmyard  manure,  crop  residues,  etc.,  speedily  change 
to  nitrates  in  the  soil.  The  intermediate  steps  are  unknown,  but 
a  beginning  has  been  made  this  year  by  Mr.  Horton  who  is  investi- 
gating the  nature  of  the  organic  substances  present  in  the  soil. 
The  work  is  necessarily  slow  and  difficult,  but  until  it  is  done  a  satis- 
factory solution  of  the  problem  will  not  be  possible. 

The  complete  system  of  crop  and  soil  sampling  adopted  at 
Rothamsted  enables  us  to  make  up  balance  sheets  showing  what 
becomes  of  the  transformed  nitrogen  compounds.  These  prove  that 
the  nitrification  process  is  not  complete ;  a  portion  of  the  added 
nitrogen  compound  does  not  appear  as  nitrate,  and  some  of  it  indeed 
cannot  be  traced  at  all.  The  last  balance  sheet  was  made  up  in 
1894 ;  but  the  plots  are  now  being  re-surveyed  so  as  to  bring  it  up 
to  date  and  to  show  the  relative  efficiency  of  the  various  manurial 
schemes  in  use  at  Rothamsted.  It  is  already  evident,  however, 
that  certain  methods  and  especially  those  involving  the  use  of  much 
farmyard  manure,  are  wasteful  of  nitrogen,  and  on  some  of  the  plots 
less  than  50  per  cent,  of  the  added  nitrogen  is  recovered  in  the  crop; 
but  it  is  not  known  how  the  waste  occurs  or  whether  it  is  an  inevit- 
able accompanyment  of  high  farming. 

The  assumption  has  been  made  that  in  these  cases  an  evolution 
of  gaseous  nitrogen  takes  place,  and  this  is  of  considerable  scientific 
interest  because  no  biochemical  process  is  known  that  would  liberate 
gaseous  nitrogen  under  the  conditions.  But  the  economic  interest 
is  much  greater.  Nitrogenous  manures  are  by  far  the  most  expen- 
sive, while  stable  or  yard  manure  constantly  tends  to  become  dearer 
to  make  and  harder  to  buy.  In  modern  agricultural  conditions  it  is 
essential  to  reduce  waste  and  to  get  the  greatest  possible  return 
from  the  manures  applied — indeed,  the  unsuccessful  farmer  often 
differs  from  the  successful  man  only  in  allowing  to  go  unchecked 
a  series  of  wastages,  each  in  itself  small.  A  careful  study  has 
therefore  been  begun  to  trace  the  missing  nitrogen,  to  find  out  how 
it  gets  lost  and  whether  there  is  any  means  of  saving  it.  Mr. 
Appleyard  is  conducting  experiments  to  see  if  gaseous  nitrogen   is 


given  off  from  the  soil,  but  has  failed  to  find  any  considerable 
evolution,  and  it  soon  became  clear  that  the  reaction,  if  it  takes 
place  at  all,  goes  on  too  slowly  to  be  studied  in  a  limited  time  in  the 
laboratory. 

The  way  round  a  difficulty  of  this  sort  is  to  seek  out  and  study 
carefully  an  exaggerated  case  as  nearly  as  possible  parallel  to  the 
one  in  hand,  and  we  had  an  obvious  instance  in  a  manure  heap, 
where  marked  losses  of  nitrogen  take  place  from  its  compounds. 
A  manure  heap,  however,  is  an  extraordinarily  complex  problem  to 
attack  and  required  far  more  time  than  we  could  give  it.  Fortunately, 
the  Hon.  Rupert  Guinness  came  forward  and  enabled  us  to  secure  the 
services  of  Mr.  E.  H.  Richards,  formerly  of  the  Sewage  Commission, 
who  now  devotes  himself  entirely  to  this  question.  We  are  now,  there- 
fore, steadily  developing  our  attack  :  while  Messrs.  Horton  and 
Appleyard  are  studying  the  chemical  processes  in  the  soil,  Mr. 
Richards  is  investigating  the  much  more  intense  processes  in  the 
manure  heap.  Apart  from  the  valuable  light  this  last  investigation 
may  be  expected  to  throw  on  the  soil  work,  it  is  of  great  intrinsic 
importance  by  reason  of  its  general  bearing  on  the  nitrogen  losses 
from  the  farm. 

The  agents  bringing  about  the  production  of  nitrate,  the  loss  of 
nitrogen,  and  apparently  other  reactions  in  the  soil,  are  bacteria, 
and  these  are  being  studied  in  the  James  Mason  Laboratory  by  Dr. 
Hutchinson  and  Mr.  MacLennan.  Hitherto  they  have  been  dealt 
with  in  groups  only,  but  it  has  now  become  necessary  to  make 
a  closer  study  of  the  various  types,  and  about  a  hundred  have 
accordingly  been  isolated  and  grown  in  pure  culture. 

The  stock  of  soil  bacteria  appears  to  be  remarkably  varied  ;  Mr. 
Buddin  finds  some  which  can  develope  in  presence  of  strong 
organic  poisons,  such  as  phenol,  cresol,  hydroquinone,  etc.,  and, 
indeed,  apparently  feed  on  these  substances. 

The  conditions  under  which  soil  bacteria  work  have  for  some 
years  been  under  investigation  here,  and  in  last  year's  Report 
reference  was  made  to  experiments  showing  that  the  bacteria  are 
not  the  only  active  organisms  in  the  soil,  but  that  other  and  larger 
organisms  are  present  which  are  inimical  to  them  and  keep  their 
numbers  down.  Provisionally  these  organisms  were  identified  with 
soil  protozoa,  and  a  survey  of  the  soil  fauna  was  begun  to  ascertain 
if  protozoa  were  present  in  our  soil,  and,  if  so,  whether  they  acted 
detrimentally  to  bacteria.  Various  forms  were  isolated  from  hay 
infusions  inoculated  with  soil,  but  there  was  nothing  to  show 
whether  they  occurred  in  the  soil  in  active  forms  or  as  cysts. 
Fortunately,  Mr.  Martin  devised  a  method  by  which  some  of  the 
protozoa  can  be  extracted  from  the  soil  in  the  form  in  which  they 
actually  exist,  and  he  and  Mr.  Lewin  have  shown  that  numbers  of 
amoebae  and  of  flagellates  are  in  the  active  form  and  some  at  least 
feed  on  bacteria  in  the  soil.  The  amoebae  are  at  present  under 
investigation,  and  prove  to  be  new  forms  of  considerable  interest. 

When  soil  is  treated  with  mild  antiseptics,  gentle  heat,  or  in 
other  ways  inimical  to  life,  it  is  found  that  the  soil  bacteria,  after 
a  preliminary  depression  finally  multiply  more  rapidly  than  before, 
and  the  harmful  factor  is  put  out  of  action.  Dr.  Hutchinson  and 
Mr.  MacLennan  have  shown  that  quicklime  behaves  like  other 
antiseptics  and  causes  first  a  depression  and  then  a  great  increase 


10 


in  bacterial  numbers,  but  a  permanent  depression  in  soil  protozoa. 
The  rate  of  ammonia  production  also  shows  the  usual  increase. 
Thus  quicklime  owes  part  of  its  effect  to  its  sterilising  action.  This 
discovery  throws  important  light  on  the  behaviour  of  lime  in  soil 
and  clears  up  much  that  has  long  been  obscure.  Other  effects  of 
lime  on  the  soil  of  a  chemical  and  physical  nature  were  observed 
and  investigated. 

The  usual  demonstrations  have  been  continued  showing  the 
improvement  in  productiveness  brought  about  by  partial  sterilisation. 
Several  large  scale  trials  have  been  made  in  commercial  glasshouses. 
The  new  Experiment  Station  in  Lea  Valley,  now  in  course  of 
formation,  will  in  future  take  over  much  of  this  demonstration 
work.  The  laboratory  work  has  been  continued  in  conjunction  with 
Mr.  Buddin,  who  has  been  investigating  the  effect  of  certain  typical 
organic  antiseptics  with  a  view  to  devising  some  general  schemes 
of  classification  of  substances  suitable  for  practical  application. 

An  investigation  by  Dr.  Hutchinson  and  Mr.  Goodey  of  the 
samples  of  soil  collected  from  our  plots  at  various  periods  and  stored 
in  dry  condition  has  further  illustrated  the  close  parallelism  estab- 
lished in  earlier  papers  between  the  soil  protozoa  and  the  factor 
detrimental  to  bacteria.  Samples  collected  and  bottled  in  1874 
behaved  normally  on  moistening — the  bacteria  developed,  but  not  to 
any  very  great  extent — amoebae  and  flagellates  were  found ;  on 
partial  sterilisation  the  protozoa  were  killed  and  the  bacterial 
numbers  rose  in  the  usual  way.  Samples  of  soil  collected  and 
bottled  in  1846  and  dried  in  1880,  however,  behaved  like  soil 
already  partially  sterilised:  on  moistening,  the  bacterial  numbers 
rose  considerably,  no  protozoa  were  found,  and  no  further  change 
was  produced  by  partial  sterilisation.  Thus  long  storage  in  dry 
condition  causes  the  soil  to  lose  the  factor  detrimental  to  bacteria, 
and  it  also  loses  its  protozoa. 

Besides  the  detrimental  organisms  already  referred  to,  another 
factor  influencing  the  soil  decompositions  has  been  revealed  this 
year.  Determinations  of  the  nitrate  content  of  our  arable  soils  have 
shown  that  there  is  always  less  accumulation  of  nitrate  on  our 
cropped  than  on  our  fallow  plots,  even  after  allowing  for  the  nitrate 
taken  up  by  the  plant.  Examination  of  the  data  obtained  here  and 
elsewhere  indicates  that  the  growing  crop  in  some  way  interferes 
with  the  process  of  ammonia  and  nitrate  formation.  It  does  not 
appear  that  the  effect  is  merely  accidental  and  due  to  some  climatic 
factor,  for  Lyttleton  Lyon  has  already  obtained  a  similar  result  at 
Ithaca.  Field  experiments  alone  are  not  sufficient  to  solve  the 
problem  ;  a  proper  series  of  pot  experiments  is  required.  There  are, 
however,  several  important  consequences  of  such  an  interaction 
between  the  growing  plant  and  the  soil  bacteria,  should  it  be  proved 
to  exist.  If  the  growing  crop  interferes  with  the  process  of  ammonia 
and  nitrate  formation  it  is  obvious  that  one  crop  may  be  expected 
adversely  to  affect  another.  Mr.  Pickering's  grass  growing  experi- 
ments afford  evidence  that  such  an  interference  does  take  place : 
there  is,  moreover,  a  strong  opinion  to  this  effect  among  practical 
men  and  the  American  Bureau  of  Soils  has  accepted  it,  and  put  for- 
ward a  hypothesis  in  explanation,  one,  however,  which  we  were 
unable  to  confirm  at  Rothamsted. 

Dr.  Hutchinson's  experiments  suggest  that  the  Pickering  effect  is 


1 1 


only  produced  in  presence  of  soil  bacteria,  thus  affording  further 
evidence  of  an  interaction  between  the  growing  plant  and  the  de- 
composition processes.  Experiments  on  the  effect  of  weeds  on 
crops  and  of  cross  cropping  were  started  last  year  in  conjunction 
with  Dr.  Brenchley  to  enable  the  facts  to  be  determined  more  com- 
pletely, and  these  are  still  going  on. 

A  further  consequence  of  such  an  interference  between  the 
plant  and  the  soil  bacteria  is  interesting  in  the  study  of  plant  nutri- 
tion. It  has  been  commonly  supposed  that  the  plant  must  in  natural 
conditions  get  most  or  all  of  its  nitrogen  as  nitrate  because  the  acti- 
vities of  the  nitrifying  organisms  leave  it  no  option,  and  the  argu- 
ment was  justified  so  long  as  it  could  be  supposed  that  nitrification 
went  on  independently  of  the  growing  plant.  But  if  it  turns  out 
that  the  plant  interferes  with  the  production  of  nitrate  and  ammonia 
in  soil  then  the  necessity  for  the  supposition  disappears  and  it  may 
equally  be  possible  for  the  nitrogen  to  be  taken  in  other  forms. 

A  beginning  has  also  been  made  this  year  with  a  systematic 
investigation  of  the  soil  as  a  medium  for  biological  activity.  This 
has  involved  a  study  of  the  constitution  of  the  soil,  and  already  three 
distinct  lines  of  work  are  bringing  out  the  biological  importance  of 
the  soil  colloids.  Mr.  Prescott  has  been  engaged  in  working  out  the 
effect  of  dilute  acids  on  the  soil,  and  Mr.  B.  A.  Keen  has  been 
determining  the  rate  of  evaporation  of  water  from  the  soil,  while  Mr. 
Appleyard  has  been  studying  the  gases  absorbed  by  the  soil  and 
given  up  only  in  a  vacuum.  The  experiments  are  not  sufficiently 
advanced  to  justify  discussion  in  this  Report,  but  they  promise  to 
throw  light  on  the  constitution  of  the  soil. 

The  composition  of  the  soil  atmosphere  at  a  depth  of  6  inches 
below  the  surface  has  been  determined  periodically  during  the  year 
by  Mr.  Appleyard,  and  it  has  been  shown  to  approximate  very 
closely  to  that  of  ordinary  air,  so  that  organisms  growing  in  the  sur- 
face soil  will  find  an  atmosphere  with  practically  normal  oxygen 
content. 

The  second  great  division  of  the  Rothamsted  work — the  investi- 
gation of  the  plant — is  still  in  its  opening  stages,  although  marked 
advances  have  been  made  during  the  year.  Dr.  Brenchley  has 
closed  her  work  on  the  effect  of  inorganic  poisons  on  plant  growth 
and  has  prepared  a  monograph  in  which  her  own  and  other  experi- 
ments are  set  out  and  the  results  discussed.  The  results  are 
definitely  against  the  hypothesis  that  all  such  poisons  act  as  stimuli 
when  applied  in  small  quantities.  Increased  yields  that  require 
further  examination  were,  however,  obtained  in  some  instances  with 
boric  acid  and  with  manganese  salts.  Dr.  Brenchley  is  now  turning 
to  the  effect  of  certain  organic  substances  on  plant  growth  and  will 
also  test  systematically  the  substances  isolated  from  the  soil  by  the 
soil  chemists. 

An  interesting  investigation  has  been  begun  by  Miss  Adam  into 
the  anatomical  structure  of  certain  of  the  grasses  on  the  Park  grass 
plots.  It  has  been  observed  that,  where  potash  manures  are  with- 
held, the  grasses  do  not  stand  up  well  but  tend  to  become  "laid." 
Microscopic  examination  is  being  made  to  see  whether  this  is 
accompanied  by  any  modification  in  the  anatomical  structure. 

The  chemical  side  of  the  work  has  progressed  steadily.  The 
usual  methods  of  analysing  crops  are  based  on  old  investigations 


12 


made  before  the  advent  of  modern  organic  chemistry.  Pharma- 
cologists have  already  adopted  newer  methods  and  we  are  now  doing 
so  for  farm  crops.  During  the  past  two  years  Messrs.  Davis  and 
Daish,  assisted  by  Mr.  Sawyer,  have  worked  out  a  satisfactory 
method,  of  which  details  are  given  below,  for  estimating  cane 
sugar,  dextrose,  laevulose,  and  maltose  in  plants.  A  further  method 
is  now  being  elaborated  for  determining  the  amount  of  starch ;  this 
is  based  on  the  fact  that  Taka  diastase  hydrolyses  starch  completely 
to  maltose  and  dextrose,  no  dextrin  being  formed. 

The  following  papers  have  been  published  during  the  year : — 

I.  "The    Weeds   of  Arable   Land."      III.      WINIFRED    E. 

Brenchley.    Annals  of  Botany,  1913.     27,  141 — 266. 

In  previous  seasons  the  investigation  had  been  confined  to 
sedentary  soils;  this  year  (1912),  however,  the  records  were  taken 
on  the  drift  soils  of  Norfolk.  The  general  results,  however,  are 
closely  in  agreement  with  those  obtained  before,  but  the  Norfolk 
weed  flora  agrees  more  closely  with  that  of  Bedfordshire  than  with 
that  of  the  West  Country.  As  before,  the  association  between  weeds 
and  soil  is  sometimes  general,  sometimes  only  local,  but  the  follow- 
ing weeds  were  characteristic  of  the  soils  examined  this  year : — 
Clay  &  Heavy  Loam.  Loams. 

Alopecurus  myosuroides  Anthemis  Cotula 

Geranium  dissectum  Bellis  perennis 

Heracleum  Sphondylium  Brassica  alba 

Linaria  Elatine  Chrysanthemum  leucanthemum 

Potentilla  reptans  Euphorbia  Peplus 

Ranunculus  arvensis  Lolium  perenne 

Stachys  palustris  Lychnis  dioica 

Papaver  Argemone 
Sand  cS:  Sandy  Loams.  Sands. 

Chrysanthemum  segetum  Bromus  mollis 

Rumex  Acetosella  Echium  vulgare 

Scleranthus  annuus  Erophila  verna 

Spergula  arvensis  Lycopsis  arvensis 

Myosotis  collina 
Chalk. 
Artemisia  vulgaris  Euphorbia  Helioscopia 

Cichorium  Intybus  Linaria  vulgaris 

Crepis  virens 

A  relationship  was  found  between  the  weed  flora  and  the  crop 
dependent  on  the  purity  of  the  crop  seed,  the  habit  of  growth  of  the 
crop,  and  the  character  of  the  cultivation  given. 

II.  "A  Study  of  the  Methods  of  Estimation  of  Carbohydrates, 

especially  in  Plant  Extracts."  W.  A.  Davis  &  A.  J. 
DAISH.  [ournal  of  Agricultural  Science,  1913.  45, 
437—468. 

A  careful  study  has  been  made  of  the  various  methods  by  which 
the  sugars  can  be  determined  in  crops  and  those  most  suitable  have 
been  embodied  in  a  scheme  which  has  been  found  to  work  satisfac- 
torily. 


13 


The  plant  material  is  extracted  in  a  large  metal  Soxhlet  ex- 
tractor for  18  hours.  The  extract  is  then  evaporated  in  vacuo 
(700  to  740  mm.)  to  a  small  volume  and  made  up  to  a  definite  volume, 
e.g.  500  c.c.  Of  this  2  portions  of  20  c.c.  each  are  evaporated  to  dry- 
ness and  dried  in  vacuo  for  18  hours  at  100°C.  This  gives  the 
total  dry  matter  in  the  extract.  440  c.c.  are  treated  with  the  requisite 
volume  of  basic  lead  acetate  solution,  filtered  under  pressure  on  a 
Buchner  funnel,  washed  and  made  up  to  a  known  volume,  2  litres. 
This  is  called  Solution  A. 

300  c.c.  of  solution  A  are  deleaded  by  means  of  solid  Na2  COg 
and  made  up  to  500  c.c.     This  is  called  Solution  B. 

(1)  25  c.c.  of  B  are  used  for  direct  reduction  and  polarised;  * 
the  reduction  is  due  to  dextrose,  laevulose,  maltose,  pentoses. 

(2)  For  Cane  Sugar.     Invert  50  c.c.  of  B : 

(a)  By  invertase.  Make  neutral  to  methyl  orange  by  a 
few  drops  of  concentrated  sulphuric  acid,  and  add  1 — 2  c.c.  auto- 
lysed  yeast  and  two  or  three  drops  of  toluene  and  leave  24 
hours  at  38 — 40°C.  After  this  period,  add  5  to  10  c.c.  alumina 
cream,  filter  and  wash  to  100  c.c.  Take  the  reducing  power 
of  50  c.c.  (  =  25  c.c.  B)  and  polarise. 

(b)  By  10  per  cent,  citric  acid.  Make  faintly  acid  to  methyl 
orange  by  a  few  drops  of  concentrated  sulphuric  acid  and  add 
a  weighed  quantity  of  citric  acid  crystals  so  as  to  have  10  per 
cent,  of  the  crystalline  acid  (C6H807  +  H20)  present.  Boil 
10  minutes,  cool,  neutralise  (to  phenolphthalein)  with  sodium 
hydroxide,  make  to  100  c.c.  and  determine  reducing  power  of 
50  c.c.  (  =  25  c.c.  B) ;  polarise. 

Cane  SUGAR  is  calculated  from  the  increase  of  reducing 
power  or  change  of  rotation  caused  by  inversion.  The  values 
obtained  by  the  two  methods  a  and  b  should  agree  closely. 

(3)  For  Maltose.  Another  300  c.c.  of  Solution  A  is  deleaded 
by  means  of  hydrogen  sulphide  and  filtered,  the  precipitated  sulphide 
being  washed  until  the  total  volume  of  filtrate  and  washings  is  about 
450  c.c.  Air  is  then  sucked  through  this  for  about  l\  hours  to  expel 
hydrogen  sulphide,  a  very  little  ferric  hydroxide  is  added  to  remove 
the  last  traces  of  the  latter,  and  the  solution  is  made  to  500  c.c.  It 
is  filtered  and 

50  c.c.  fermented  (a)  with  S.  marxianus 
,,              ,,            {b)      ,,     S.  anomalus 
(c)      „     S.  exiguus 
and  two  lots  d  and  e  of  50  c.c.  are  fermented  with  baker's  yeast. 
It  is  generally  necessary  in  order  to  ensure  good  growth  of  the  yeast 
to  reduce  the  acidity  by  adding  2  to  5  c.c.  of  N -sodium  carbonate  to 
the  50  c.c.  to  be  fermented ;   5  c.c.  of  sterilised  yeast  water  is  also 
added,  the  mixture  is  sterilised  in  the  usual  way  and  inoculated  in 
the  inoculating  chamber  with  the  pure  culture  of  yeast.      It  is  then 
stoppered  with  cotton  wool  and  the  yeast  allowed  to  incubate  for  21 
to  28  days  at  25°.  __J 

*  The  polarisation  of  these  dilute  solutions  is  usually  small  and  it  is  therefore 
necessary  to  take  the  reading  with  a  long  tube  (at  least  200  mm.  in  length)  with 
an  instrument  reading  accurately  to  jfo°,  trje  temperature  being  maintained  con- 
stant at  20°  C  within  1J?T0.  It  is  an  easy  matter,  using  a  Lowry  thermo-regulator 
and  circulating  the  water  by  means  of  a  small  pump,  to  keep  the  temperature 
constant  to  y^0  but  differences  of  temperature  less  than  -j^°  hardly  make  a  per- 
ceptible difference  in  the  readings  with  such  dilute  solutions  as  these. 


14 


After  completion  of  fermentation  5  c.c.  alumina  cream  is  added, 
the  solution  made  to  100  c.c.  at  15°,  filtered,  and  50  c.c.  used  for  re- 
duction. The  difference  between  the  average  reduction  with  a,  b, 
c  and  the  average  of  d  and  e  gives  the  reduction  due  to  maltose. 

(4)  Pentoses.  These  are  approximately  determined  in  50 
c.c.  of  A,  by  distilling  with  hydrochloric  acid  according  to  the 
A.O.A.C.  method  weighing  as  phloroglucide. 

(5)  When  the  reduction  due  to  pentose  and  maltose  has  been 
allowed  for  in  1,  the  remaining  direct  reduction  is  due  to  dextrose 
and  laevulose ;  the  actual  proportions  of  these  two  sugars  are  cal- 
culated from  the  reducing  power  combined  with  the  corrected  rotation 
as  suggested  by  Brown  and  Morris  in  the  1 893  paper. 

III.  "A  Simple  Laboratory  Apparatus  for  the  Continuous 

Evaporation  of  Large  Volumes  of  Liquid  in  Vacuo." 
W.  A.  Davis.  Journal  of  Agricultural  Science,  1913. 
5,  434—436. 

A  description  of  a  simple  apparatus  used  in  the  above  analytical 
process. 

IV.  "The  Soil  Solution  and  the  Mineral  Constituents  of  the 

Soil:'  A.  D.  Hall,  Winifred  E.  Brenchley  and 
Lilian  M.  Underwood.  Philosophical  Transactions 
of  the  Royal  Society,  1913.     204,  179—200. 

Solutions  were  made  by  extracting  the  soils  from  certain  of  the 
Rothamsted  plots  on  which  wheat  and  barley  had  been  grown  for 
60  years  and  upwards.  Wheat  and  barley  were  grown  in  these 
solutions,  which  were  renewed  fortnightly.  The  comparative  growth 
in  the  solutions  was  closely  parallel  to  the  growth  of  the  crop  on  the 
plots  in  the  field  and  corresponded  to  the  composition  of  the  solutions. 
The  composition  of  the  solutions  as  regards  phosphoric  acid  and 
potash  corresponded  to  the  past  manurial  treatment  of  the  soils  and 
to  the  amount  of  phosphoric  acid  and  potash  they  now  show  on 
analysis.  Growth  in  the  soil  solutions  agreed  with  the  growth  in 
artificial  culture  solutions  containing  equivalent  amounts  of  phos- 
phoric acid  and  potash.  Growth  in  the  soil  solutions  from  imperfectly 
manured  plots  was  brought  up  to  the  level  of  that  in  the  solutions 
from  completely  manured  plots  on  making  up  their  deficiencies  in 
phosphoric  acid  and  potash  by  the  addition  of  suitable  salts.  The 
phosphoric  acid  and  potash  content  of  the  soil  solutions  wras  of  the 
same  order  as  the  phosphoric  acid  and  potash  content  of  the  natural 
drainage  water  from  the  same  plots. 

Wheat  grew  as  well  as  barley  in  the  solutions  of  the  wheat  soils 
and  vice  versa.  In  similar  sets  of  solutions  from  the  same  soils 
the  growth  of  buckwheat,  white  lupins  and  sunflowers  corresponded 
with  that  of  wheat  and  barley.  Boiling  effected  no  alteration  in  the 
nutritive  value  of  the  soil  solutions. 

In  nutritive  solutions  of  various  degrees  of  dilution  the  growth  of 
plants  varied  directly,  but  not  proportionally,  with  the  concentration 
of  the  solution,  though  the  total  plant  food  present  in  the  solution 
was  in  excess  of  the  requirements  of  the  plant.  When  the  nutrient 
solution  was  diffused  as  a  film  over  sand  or  soil  particles,  as  in 
nature,  there  was  no  retardation  of  growth  due  to  the  slowness  of 


15 


the  diffusion  of  the  nutrients  to  the  points  in  the  liquid  film  which 
had  been  exhausted  by  contact  with  the  roots.  Growth  in  such 
nutrient  solutions  forming  a  film  over  sand  particles  was  much 
superior  to  the  growth  in  a  water  culture  of  equal  concentration, 
but  the  growth  in  the  water  culture  was  similarly  increased  if  a 
continuous  current  of  air  was  kept  passing  through  it. 
From  these  data  it  is  concluded : — 

(1)  The  composition  of  the  natural  soil  solution  as  regards 
phosphoric  acid  and  potash  is  not  constant,  but  varies  significantly 
in  accord  with  the  composition  of  the  soil  and  its  past  history. 

(2)  Within  wide  limits  the  rate  of  growth  of  a  plant  varies  with 
the  concentration  of  the  nutritive  solution,  irrespective  of  the  total 
amount  of  plant  food  available. 

(3)  When  other  conditions,  such  as  the  supply  of  nitrogen, 
water,  and  air  are  equal,  the  growth  of  the  crop  will  be  determined 
by  the  concentration  of  the  soil  solution  in  phosphoric  acid  and 
potash,  which,  in  its  turn,  is  determined  by  the  amount  of  these 
substances  in  the  soil,  their  state  of  combination,  and  the  fertiliser 
supplied. 

(4)  On  normal  cultivated  soils  the  growth  of  crops  like  wheat 
and  barley,  even  when  repeated  for  60  years  in  succession,  does  not 
leave  behind  in  the  soil  specific  toxic  substances  which  have  an 
injurious  effect  upon  the  growth  of  the  same  or  other  plants  in  the 
soil. 

The  net  result  of  these  investigations  is  to  restore  the  earlier 
theory  of  the  direct  nutrition  of  the  plant  by  fertilisers.  The  com- 
position of  the  soil  solution  which  determines  the  growth  of  the  plant 
is  dependent  upon  the  amount  and  the  mode  of  combination  of  the 
phosphoric  acid  and  potash  in  the  soil,  both  of  which  are  affected  by 
the  fertiliser  supply,  though  to  what  extent  is  not  yet  determinable. 

V.  "The  Effect  of  Partial  Sterilisation  of  Soil  on  the  Pro- 
duction of  Plant  Food.  Part  II.  The  Limitation  of 
Bacteria  Numbers  in  Normal  Soils  and  Its  Consequence" 
E.  J.  Russell  and  H.  B.  Hutchinson.  Journal  of 
Agricultural  Science,  1913.     5,  152—221. 

The  conclusions  reached  in  the  previous  paper  have  been  con- 
firmed and  extended.  Fresh  evidence  is  adduced  that  bacteria  are 
not  the  only  inhabitants  of  the  soil,  but  that  another  group  of 
organisms  occurs,  detrimental  to  bacteria,  multiplying  more  slowly 
under  soil  conditions  and  possessing  lower  power  of  resistance  to 
heat  and  to  antiseptics. 

In  consequence  of  the  presence  of  these  detrimental  organisms, 
the  number  of  bacteria  present  in  the  soil  at  any  time  is  not  a 
simple  function  of  the  temperature,  moisture  content  and  other  con- 
ditions of  the  soil.  It  may,  indeed,  show  no  sort  of  connection  with 
them  ;  thus  rise  of  temperature  is  found  to  be  ineffective  in  increas- 
ing the  bacteria  in  the  soil ;  increase  in  moisture  content  has  also 
proved  to  be  without  action.  The  number  of  bacteria  depends  on 
the  difference  in  activity  of  the  bacteria  and  the  detrimental 
organisms. 

But  when  soil  has  been  partially  sterilised  the  detrimental 
organisms  are  killed  and  the  bacteria  alone  are  left.  It  is  then 
found  that  increase  in  temperature  (up  to  a  certain  point)   favours 


16 


bacteria]  multiplication  and  causes  the  numbers  to  rise.  Variations 
in  moisture  content  also  produce  the  normal  results  on  partially 
sterilised,  but  not  on  untreated,  soils. 

The  detrimental  organisms  are  killed  by  any  antiseptic  vapour, 
or  by  heating  the  soil  for  three  hours  to  55°-60°C  :  they  suffer  con- 
siderably when  the  soil  is  maintained  at  lower  temperatures  (40°C) 
for  a  sufficient  length  of  time.  Cooling  to  low  temperatures  also 
depresses  them,  although  it  fails  to  kill  them. 

The  completeness  of  the  process  can  be  accurately  gauged  by 
the  extent  to  which  the  bacteria  suffer.  Whenever  the  treatment  is 
sufficiently  drastic  to  kill  the  nitrifying  organisms  and  to  reduce 
considerably  the  numbers  of  the  other  bacteria  (as  shown  by  the 
counts  on  gelatine  plates)  it  also  kills  the  detrimental  organisms. 
If  the  soil  conditions  are  now  made  normal,  and  the  antiseptic  is 
completely  removed,  rapid  increase  is  observed  in  the  bacterial 
numbers  and  the  rate  of  production  of  ammonia.  A  temporary  or 
partial  suppression  of  the  factor  is,  however,  possible  without 
extermination  of  the  nitrifying  organisms. 

Once  the  detrimental  organisms  are  killed,  the  only  way  of 
introducing  them  again  is  to  add  some  of  the  untreated  soil.  But 
the  extent  of  the  transmission  is  apt  to  be  erratic,  being  sometimes 
more  and  sometimes  less  complete  than  at  others ;  occasionally  the 
infection  fails  altogether.  We  have  not  yet  learned  the  precise 
conditions  governing  the  transmission. 

Provisionally  we  identify  the  detrimental  organisms  with  the 
active  protozoa  of  the  soil,  but  as  the  zoological  survey  is  yet 
incomplete  we  do  not  commit  ourselves  to  any  particular  organism 
or  set  of  organisms,  or  to  any  rigid  and  exclusive  definition  of  the 
term  protozoa. 

The  increase  in  bacterial  numbers  following  after  partial  steri- 
lisation by  volatile  antiseptics  is  accompanied  by  an  increase  in  the 
rate  of  ammonia  production  until  a  certain  amount  of  ammonia  or 
of  ammonia  and  nitrate  has  been  accumulated,  when  the  rate  falls. 
Thus  two  cases  arise  :  (1)  when  only  small  amounts  of  ammonia 
and  nitrate  are  present  there  is  a  relationship  between  bacterial 
numbers  and  the  rate  of  ammonia  production ;  (2)  when  large 
amounts  of  ammonia  or  of  ammonia  and  nitrate  are  present  there 
is  no  relationship.  The  limit  varies  with  the  composition  and  con- 
dition of  the  soil. 

Complications  are  introduced  when  the  soil  has  been  partially 
sterilised  by  heat,  because  heat  effects  an  obvious  decomposition  of 
the  organic  matter,  thus  changing  the  soil  as  a  medium  for  the 
growth  of  micro-organisms.  The  bacterial  flora  is  also  very  con- 
siderably simplified  through  the  extermination  of  some  of  the  varie- 
ties. These  effects  become  more  and  more  pronounced  as  the 
temperature  increases,  and  their  tendency  is  to  reduce  the  numbers 
of  bacteria.  We  find  maximum  bacterial  numbers  in  soils  that 
have  been  heated  to  the  minimum  temperature  necessary  to  kill  the 
detrimental  organisms  (about  60°C).  Both  bacterial  numbers  and  the 
rate  of  decomposition  in  such  soils  approximate  to  those  obtaining 
in  soils  treated  with  volatile  antiseptics,  and  the  above-mentioned 
relationships  between  these  quantities  also  hold. 

Although  bacterial  numbers  are  at  a  minimum  in  soils  heated 
to  100°,  the  decomposition  effected  is  at  a  maximum. 


17 


With  this  exception,  it  is  generally  true  that  bacterial  multipli- 
cation may  go  on  without  increasing  the  rate  of  production  of 
ammonia,  but  an  increase  in  the  rate  of  production  of  ammonia  does 
not  take  place  without  bacterial  multiplication. 

The  increase  in  bacterial  numbers  brought  about  by  addition  of 
bacteria  from  the  untreated  soil  into  partially  sterilised  soil  leads  to 
still  further  production  of  ammonia  and  nitrate,  unless  too  large 
a  quantity  of  these  substances  is  already  present.  But  the  sub- 
sequent depression  in  bacterial  numbers  consequent  on  the  develop- 
ment of  the  detrimental  organisms  is  generally  (though  not  always) 
without  effect  on  the  rate  of  decomposition,  apparently  because  it 
does  not  set  in  until  too  late. 

VI.  "The   Partial  Sterilisation  of  the    Soil    by    means    of 

Caustic  Lime"  H.  B.  Hutchinson.  Journal  of 
Agricultural  Science,  1913.     5,  320—330. 

When  a  soil  is  treated  with  lime,  either  in  the  caustic  or  mild 
form,  an  improvement  of  its  physical  condition  results;  the  treatment 
gives  rise  to  a  certain  amount  of  chemical  action  with  a  liberation  of 
nutrient  substances,  and  also,  by  neutralising  any  acids  present, 
provides  a  more  favourable  environment  for  the  various  classes  of 
organisms  existing  in  the  soil. 

This  in  itself  is  not  sufficient  to  account  for  many  of  the  results 
that  are  obtained  in  practice.  Caustic  lime  has  a  recognised  value 
as  an  antiseptic  and,  when  applied  to  the  soil,  even  in  the  presence 
of  large  quantities  of  calcium  carbonate,  has  a  pronounced  effect  in 
disturbing  or  even  destroying  the  state  of  equilibrium,  normally 
existing  between  the  micro-flora  and  the  micro-fauna  of  the  soil. 

The  action  of  caustic  lime  has  been  found  to  be  intermediate  in 
character  between  that  exercised  by  volatile  antiseptics  and  the 
changes  induced  by  high  temperatures.  In  addition  to  killing  many 
bacteria  and  causing  the  death  of  the  larger  protozoa,  which  would 
appear  to  exert  a  depressive  action  on  the  growth  of  bacteria,  it 
brings  about  a  decomposition  of  the  organic  nitrogenous  constituents 
of  the  soil.  It  is  highly  probable  that  these  decomposition  products 
serve  as  nutrients  for  bacteria  and  are  subsequently  resolved  into 
plant  food. 

The  depression  of  bacterial  activities  in  soils  treated  with 
caustic  lime  would  appear  to  persist  until  all  the  oxide  has  been  con- 
verted into  carbonate  ;  this  is  followed  by  a  period  of  active  bacterial 
growth  and  increased  production  of  plant  food.  The  inhibitory 
action  of  caustic  lime  on  soil  bacteria  varies  writh  the  soil  and  is 
possibly  governed  by  the  organic  matter  present. 

In  the  main,  pot  experiments  give  results  similiar  to  those  ob- 
tained in  the  Laboratory  by  bacteriological  and  chemical  analyses. 

VII.  "The  Action  of  Antiseptics  in  increasing  the  Growth 
of  Crops  in  Soil.  E.  J.  RUSSELL  and  WALTER 
Buddin.  Journal  of  the  Society  of  Chemical  Industry, 
1913.     32. 

Chemical  substances  are  now  being  put  upon  the  market  for 
partial  sterilisation  of  soils,  and  this  paper  is  intended  to  afford 
guidance  to  the  works  chemist,  who  is  called  upon  to  supervise  the 
preparation  of  such  materials.  Antiseptics  may  be  used  in  practice 
in  the  following  cases  : — 


V 


18 


(1)  Where  the  crop  yield  is  limited  to  the  supply  of  nitrogenous 
plant  food,  and  where  therefore  an  increased  production  of  ammonia 
in  the  soil  is  desirable. 

(2)  Where  disease  organisms  and  other  detrimental  forms  are 
present,  and  the  micro-organic  population  of  the  soil  has  lost  much 
of  its  effectiveness  in  producing  ammonia  from  the  nitrogen  com- 
pounds of  the  soil.  Such  soils  are  known  as  "sick"  soils  and  are 
fairly  prevalent  in  certain  types  of  high  farming  and  market 
gardening.  To  some  extent  also  sewage  sick  soils  come  into  this 
category. 

The  first  case  is  the  simplest  in  principle,  but  the  most  difficult 
in  practice,  from  the  circumstance  that  it  is  already  provided  for  by 
the  various  nitrogenous  manures  on  the  market.  Until  the  antisep- 
tic treatment  can  be  made  to  cost  less  than  a  dressing  of  a  nitro- 
genous manure,  it  will  have  no  chance  against  these  competitors. 

The  second  case  is  more  difficult  in  principle  but  easier  in 
practice  because  it  is  not  provided  for,  and  there  is  a  clear  field  here 
for  the  application  of  antiseptics  in  practice. 

The  following  is  found  to  be  roughly  the  order  of  effectiveness 
of  a  number  of  typical  antiseptics  : — 

Class  1.     Most  effective.     Formaldehyde,  pyridine. 

Class  2.  Cresol,  phenol,  calcium  sulphide,  carbon  disulphide, 
toluene,  benzene,  petrol. 

Class  3.  Least  effective.  Higher  homologues  of  benzene 
(e.g.,  heavy  solvent  naphtha),  napthalene  and  certain  of  its 
derivatives. 

None  of  these  antiseptics  is  as  good  as  steam,  either  in  increas- 
ing the  amount  of  ammonia  in  the  soil,  in  killing  insect  and  fungoid 
pests,  or  in  inducing  a  good  fibrous  root  development.  In  all  trials, 
therefore,  a  steamed  soil  is  included  to  set  the  standard  of  excellence 
previously  unattained  by  antiseptics. 

The  following  experimental  methods  have  proved  useful  in  our 
laboratories  and  may  be  adopted  by  the  works  chemist  in  sorting  out 
possible  antiseptics  for  practical  purposes  :• — Some  rejected  glass- 
house "sick"  soil — the  worse  its  character  the  better  for  the  experi- 
ment— is  divided  into  three  lots,  one  is  left  untreated  while  the 
other  two  are  treated  respectively  with  0*1  and  0*25  per  cent,  of  the 
antiseptic,  care  being  taken  that  the  admixture  is  as  far  as  possible 
perfect.     Five  experiments  are  then  carried  out : — 

(1)  Chemical  analyses  are  made  at  periodical  intervals  extend- 
ing over  a  month,  to  ascertain  the  rate  at  which  ammonia  and  nitrates 
accumulate  in  the  treated  and  untreated  soils. 

(2)  At  the  same  time,  bacteriological  counts  are  made  by  the 
gelatine  plate  method  to  ascertain  the  rate  of  development  of 
bacteria. 

(3)  Some  of  each  lot  is  inoculated  into  test  tubes  containing  a 
one  per  cent,  hay  infusion,  and  after  six  days'  incubation  at  25°C. 
drops  of  the  infusions  are  examined  under  the  low  power  of  the 
microscope  for  protozoa.  If  these  organisms  are  killed  by  the  treat- 
ment, it  commonly  happens  that  other  harmful  organisms  are  killed 
also. 

(4)  Seeds  are  sown  in  the  soils  and  the  young  plants  are  care- 
fully watched  to  observe  the  development  of  "damping  off"  root, 
knots,  or  other  diseases. 


19 

(5)  Plants  are  grown  right  through  to  fruiting  and  the  produce 
weighed. 

VIII.  "O/i  the  Growth  of  Plants  in  Partially  Sterilised 
Soils:'  E.  J.  Russell  and  F.  R.  Petherbridge. 
Journal  of  Agricultural  Science,  1913.     5,  248-287. 

Seven  important  directions  have  been  found  in  which  partially 
sterilised  soils  differ  from  untreated  soils  as  media  for  plant  growth. 

(1)  There  is  generally  a  retardation  in  germination  but  some- 
times partial  acceleration  (i.e.,  affecting  some  of  the  seeds  only). 

(2)  There  is  generally  an  acceleration  in  growth  up  to  the  time 
of  the  appearance  of  the  third  or  fourth  leaves,  but  sometimes 
a  marked  retardation,  especially  in  rich  soils  heated  to  100°C.  We 
have  failed  to  discover  the  conditions  regulating  the  retardation,  and 
can  never  predict  with  certainty  whether  or  not  it  will  set  in.  On 
the  whole  we  have  observed  it  more  frequently  during  dull  winter 
days  than  in  the  brighter  spring  or  summer  days. 

(3)  When  this  retardation  occurs  it  is  accompanied  by  a  very 
dark  green  leaf  colour  and  either  the  formation  of  a  purple  pigment 
or  a  tendency  for  the  leaves  to  curl  towards  the  under  side.  The 
whole  appearance  is  strongly  suggestive  of  an  attempt  on  the  part 
of  the  plant  to  reduce  assimilation. 

(4)  Later  on  the  purple  colour  goes  and  the  curling  ceases; 
rapid  plant  growth  then  takes  place.  The  subsequent  growth  is 
finally  proportional  to  the  amount  of  food  present. 

(5)  Plants  grown  in  soils  heated  to  100°  show  a  very  remark- 
able development  of  fibrous  root  unlike  anything  obtained  on  un- 
treated soils. 

(6)  Plants  grown  on  soils  heated  to  100°  have,  in  comparison 
with  those  on  untreated  soils,  larger  leaves  of  deeper  green  colour, 
stouter  stems,  usually  shorter  internodes ;  they  flower  earlier  and 
more  abundantly,  and  contain  a  higher  percentage  of  nitrogen  and 
sometimes  of  phosphoric  acid  in  their  dry  matter;  the  roots  and 
stems  give  up  their  nitrogen,  phosphorus,  and  potassium  more  com- 
pletely to  the  fruit. 

(7)  Plants  grown  on  soils  heated  to  55  or  treated  with  volatile 
antiseptics  show  fewer  of  these  effects ;  there  is  only  rarely  a  re- 
tardation in  seedling  growth  but  usually  an  acceleration,  sometimes 
a  rapid  one,  succeeded  by  a  period  of  steady  growth  which  is  finally 
proportional  to  the  amount  of  plant  food  present.  No  specially 
marked  development  of  fibrous  root  or  shortening  of  the  internodes 
occurs,  but  there  is  an  increase  in  the  percentage  of  nitrogen  and 
sometimes  of  phosphoric  acid  in  the  dry  matter  as  compared  with 
plants  raised  on  untreated  soils,  and  also  a  more  complete  trans- 
location of  these  materials  to  the  fruit. 

IX.  The  Effect  of  Bastard  Trenching  on  the  Soil  and  on 

Plant  Growth.     E.  J.  Russell  and  S.  U.  Pickering. 
Journal  of  Agricultural  Science,  1913.     5,  483 — 496. 
Bastard   Trenching   as   originally  performed,   consists   of  two 
distinct  operations ;  loosening  the  lower  spit  of  soil  and  digging  into 
it  farmyard  manure  or  other  fertilising  material. 

The  experiments  described  in  this  paper  were  made  on  plots  that 
had  been  bastard  trenched  to  a  depth  of  three  spits,  but  not  manured. 
The  first  and  second  spits  were  put  back  in  their  natural  order,  but 


20 


no  manure  was  added.  The  experiment,  therefore,  deals  simply 
with  deep  cultivation  effect,  and  is  not  complicated  by  any  disturbing 
factors  due  to  the  operation  of  the  manure. 

The  effect  of  bastard  trenching  on  the  soil,  when  unaccom- 
panied by  manuring,  was  found  to  be  only  small.  Beyond  a  ten- 
dency to  facilitate  the  drainage  of  water  from  the  top  spit  to  the 
lower  spit  in  the  clays  and  heavy  loams,  and  slightly  to  increase  the 
nitrates,  no  definite  change  seemed  to  be  produced.  The  effect  on 
the  growth  of  trees  appeared  to  depend  largely  on  the  character  of 
the  seasons  following  the  trenching  and  planting,  as  was  exemplified 
by  the  different  results  obtained  in  the  same  plot  of  ground  after 
trenching  in  1895,  and  after  retrenching  in  1910.  The  practical 
conclusion  may  be  drawn  that  bastard  trenching  by  itself,  done 
without  addition  of  manure  to  the  bottom  spit,  is  not  likely  to  bring 
about  any  sufficient  change  in  the  soil  to  justify  the  trouble  and  ex- 
pense of  the  operation.  Of  course,  if  there  is  a  pan  to  be  broken 
the  case  is  different ;  but  where  there  is  no  pan,  the  main  use  of 
bastard  trenching  seems  to  be  that  it  affords  an  opportunity  for 
adding  manure  or  other  fertilising  material  to  the  bottom  spit. 
Unless  advantage  is  taken  of  this,  the  real  benefit  of  the  process  is 
missed. 

X.  The  Composition  of  Rain  Water  collected  in  the  Hebrides 
and  in  Iceland."  N.  H.  J.  MlLLER.  Journal  of  the 
Scottish  Meteorological  Society,  1913.   [iii]  16,  141—158. 

Systematic  analyses  have  been  made  for  a  number  of  years  of 
the  amounts  of  ammonia  and  nitrate  in  rain.  The  question  was  at 
one  time  of  great  interest  in  connection  with  nutrition  of  crops, 
Liebig  having  maintained  that  plants  derived  a  considerable  pro- 
portion of  their  nitrogen  from  this  source.  The  analyses  have  long 
disproved  this  view  and  interest  has  now  shifted  to  another  problem  : 
the  source  of  the  ammonia  invariably  found  in  the  rain  water.  Sam- 
ples of  rain  have  been  collected  systematically  from  various  stations 
in  the  Hebrides  and  in  Iceland,  remote  from  atmospheric  pollution, 
in  order  to  ascertain  how  the  amounts  of  ammonia  and  nitrate  com- 
pare with  those  found  at  Rothamsted.    The  results  were  as  follows : — 


Rainfall 

Per  IV 

NITROGEN 

lillion 

Per  Acre,  per 
Annum  (lb.) 

As 
Ammonia 

As 
Nitrates 

As 
Ammonia 

As 
Nitrates 

Total 

Rothamsted 

Inches 
28-04 

Average 
0437 

Average 

0202 

2774 

L'2-51 

4  025 

Laudale,  Ardgour 
1  larrabead, 

88  80 

0138 

0  063 

2*784 

1260 

4044 

Berncray 

Shil lay  Monach 

Islands,  N.  Hist. 
1  intt  of   Lewis, 

3528 
4836 

0145 
0115 

0138 
0  054 

1  164 
1260 

1104 
0588 

2  268 

P848 

Stornaway 
Vifilsstadir, 

41'19 

0039 

0033 

0361 

0  305 

0  666 

Iceland     

3S'34 

0091 

0030 

0802 

0  263 

1065 

21 


All  these  samples  contain  ammonia  and  nitrate,  although  the 
amounts  are  low.  Indeed,  those  from  the  Butt  of  Lewis  and 
Vifilsstadir  are  the  lowest  hitherto  recorded,  the  amount  of  ammonia 
in  the  Butt  of  Lewis  rain  being  even  less  than  was  found  in  the 
southern  regions  by  the  Charcot  expedition. 

Seeing  that  ammonia  is  always  present,  it  is  important  to  ascer- 
tain where  it  comes  from.  The  old  theory  of  Boussingault,  that 
atmospheric  ammonia  is  derived  from  the  sea,  and  the  more  recent 
one  of  Schloessing,  that  tropical  seas  give  up  ammonia  to  the  air,  are 
not  supported  by  any  analyses  of  rain  collected  near  the  sea  in  tropi- 
cal countries,  all  of  which  show  less  ammonia  than  is  found  at 
Rothamsted.  The  only  possible  explanation  seems  to  be  that  the  soil, 
or  at  any  rate  arable  soil,  is  continually  giving  up  some  of  its 
ammonia  to  the  air.  So  that  instead  of  the  rain  contributing  three 
or  four  pounds  to  the  acre,  it  seems  more  probable  that  it  is  merely 
restoring  some  portion  of  the  ammonia  which  the  soil  has  previously 
lost. 

XI.  "The  Excystation  of  Colpoda  Cucullus  from  its  Resting 

Cysts,  and  the  Nature  and  Properties  of  the  Cyst 
Membranes"  T.  GOODEY.  Proceedings  of  the  Roval 
Society,  1913.     86  B,  427—439. 

This  research  has  shown  excystation  is  brought  about  in  con- 
sequence of  the  dissolution  of  the  cyst  membrane  by  an  enzyme,  and 
an  attempt  has  been  made  to  follow  out  the  main  steps  of  the  process. 

The  cyst  membranes  of  Colpoda  cucullus  consist  of  the  outer 
ectocyst  and  the  inner  endocyst,  and  the  reactions  of  each  have  been 
studied.  The  endocyst  appears  to  be  of  carbohydrate  nature,  but  it 
differs  from  any  other  carbohydrate  and  appears  to  be  new.  The 
name  "Cystose"  is  suggested  for  it.  During  excystation  the  endocyst 
is  set  free  by  the  rupture  of  the  etocyst,  and  the  Colpoda  liberates 
itself  by  the  rapid  digestion  of  the  endocyst  by  means  of  an  enzyme 
which  it  secretes.  This  enzyme  differs  from  diastase  and  other 
known  enzymes,  and  is  named  Cystase.  Full  details  are  given  in  the 
paper  of  the  tests  adopted  and  the  results  obtained. 

XII.  "Soil  Protozoa:'     K.  R.  Lewin  and  C.  H.  Martin. 

Nature,  1914.     92,  632  (Feb.  5,  1914). 

A  method  of  obtaining  permanent  preparations  of  protozoa  in 
the  state  in  which  they  are  living  in  the  soil. 

The  fixative  hitherto  used  in  our  experiments  has  been  picric 
acid  in  saturated  aqueous  solution,  but  we  have  since  found  this  re- 
agent to  be  less  serviceable  in  the  case  of  clay  soils  than  the 
following  mixture : — Saturated  aqueous  solution  of  mercuric  chloride, 
1  pt.;  methylated  spirit,  1  pt.  The  soil  should  be  crumbled  into 
this  fluid,  and  mixing  is  best  accomplished  by  gently  shaking  the 
containing  vessel,  care  being  taken  to  avoid  making  the  clay  com- 
ponent of  the  soil  pass  into  suspension. 

A  delicate  film  containing  protozoa  appears  on  the  surface 
of  the  liquid,  and  this  can  be  removed  by  floating  cover-slips  over  it, 
and  stained  by  the  usual  methods. 


22 

OTHER   PUBLICATIONS. 

The  following  other  publications  have  been  issued  during  the 
year : — 

"Guide  to  the  Experimental  Plots.  Rothamsted  Experimental 
Station^     2nd  Edition,  1913.     John  Murray,  l/-  net. 

"Yellow  Rattle  as  a  Weed  on  Arable  Land:'  WINIFRED  E. 
Brenchley.  Journal  of  the  Board  of  Agriculture,  1913. 
19,  1005—1009. 

"The  Complexity  of  the  Micro-organic  Population  of  the  Soil:' 

E.  J.  Russell.     Science,  1913.     37,  519—522. 
[A  reply  to  certain  American  criticisms  of  the  work  of  Russell 
and  Hutchinson.] 

"Chrysanthemum  Growing  in  Partially  Sterilised  Soils:1    E.  J. 

RUSSELL.     Transactions  of  the  National  Chrysanthemum 

Society,  1913. 

[An  account  written  for  nurserymen  of  experiments  showing  the 

effect  of  partial  sterilisation  on  the  growth  of  chrysanthemums,  and 

in  particular  that   the   partial   sterilisation   of  old   chrysanthemum 

compost  renders  it  again  suitable  for  use.] 

"The  Fertility   of  the   Soil"     E.  J.   Russell.     Cambridge 

Manuals  of  Science  and  Literature,      l/-  net. 
[A   general   account   of  the   present   position   of  soil    fertility 
problems.] 

MONOGRAPHS. 

It  is  proposed  to  bring  out  a  series  of  monographs  in  which  the 
members  of  the  Staff  will  discuss  the  particular  problems  they  have 
been  investigating,  as  soon  as  sufficient  material  has  accumulated  to 
render  such  a  course  desirable.     Two  have  already  been  written  : — 

"Soil  Conditions  and  Plant  Growth:'  E.  J.  RUSSELL.  Long- 
mans &  Co.,  5/-  net. 

"Inorganic  Plant  Poisons:'  Winifred  E.  Brenchley. 
Cambridge  University  Press.     (Ready  shortly.) 


23 


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24 


CROP  YIELDS 
ON  THE  EXPERIMENTAL  PLOTS. 


1  acre 

about       0'404  Hectare. 

1  bushel 

= 

0'364  Hectolitre. 

1  lb.  (pound  avoir.) 

= 

0'453  Kilogramme. 

1  cwt.  (hundredweight)    ... 

= 

50'8      Kilogrammes. 

1  bushel  per  acre  ... 

= 

0  9      Hectolitre  per  Hectare. 

1  lb.  per  acre          

= 

112    Kilogramme  per  Hectare. 

1  cwt.  per  acre       

= 

125*6      Kilogrammes  per  Hectare. 

CROPS  GROWN  IN  ROTATION.    AGDELL  FIELD. 

PRODUCE  PER  ACRE. 


O. 


Unmanured. 


Year. 


CROP. 


Fallow. 


6. 
Beans 

or 
Clover 


M. 

Mineral 
Manure. 


Fallow. 


4. 
Beans 

or 
Clover. 


C. 

Complete 

Mineral  and 

Nitrogenous 

Manure. 


Fallow. 


2. 
Beans 

or 
Clover. 


SIXTEENTH  COURSE,  1908-11. 


1908         Roots  (Swedes)       Cwt. 


1909 


1910 


1911 


Barley  Grain     ...    Bus. 
Barley  Straw     ...   Cwt. 

Clover  J  1st  crop    Cwt. 
Hay   (2nd  crop  Cwt. 

Wheat  Grain     ...    Bus. 
Wheat  Straw     ...  Cwt. 


216 

64 

1790 

2358 

3954 

114 

100 

17"4 

221 

268 

101 

11  3 

127 

169 

187 

_ 

16 

_ 

241 

— 

158 

— 

400 

— 

239 

245 

319 

37'8 

33  3 

204 

2L4 

286 

33'5 

29-3 

3140 

334 
23'8 

322 
445 

380 
325 


PRESENT  COURSE  (17th),  1912- 


191. 


1913 


Roots  (Swedes)       Cwt. 


Barley  Grain 
Barley  Straw 


Bus. 
Cwt. 


18-5 
8-2 


23 

246 
130 


i 
1517    I    2519 


247 
106 


332 
145 


5866    !    4630 


220 
90 


325 
150 


25 
METEOROLOGICAL  RECORDS,  1913. 

(See  "Guide,"  1913,  page  18,  Table  IX.) 


Rain. 

No.  of 

Drainage  through 
soil. 

Temperature. 

Total  Fall. 

Rainv 

Bright 

Days. 

Sun- 

20 ins. 

40  ins. 

60  ins. 

shine. 

5-inch 

ToiJTT 

T3*tTff 

Funnel 

Acre 

Acre 

deep. 

deep. 

deep. 

Max. 

Min. 

Gauge. 

Gauge. 

Gauge. 

F. 

Inches. 

Inches. 

No. 

Inches. 

Inches. 

Inches. 

Hours. 

F.    • 

Jan. 

3"  163 

3-360 

21 

3  046 

3115 

3124 

354 

454 

339 

Feb.       ... 

0953 

1004 

13 

0658 

0  767 

0785 

571 

463 

334 

March   ... 

2-406 

2-518 

21 

0833 

0891 

0886 

103  0 

509 

361 

April 

3  043 

3- 163 

20 

1409 

1528 

1537 

1170 

535 

382 

May 

1721 

1806 

12 

0748 

0880 

0  836 

206'9 

628 

438 

June 

1145 

1200 

8 

0  003 

0021 

0025 

205' 6 

671 

481 

July        ... 

1190 

1291 

12 

— 

0001 

0001 

wo 

655 

499 

August  ... 

1444 

1576 

10 

— 

— 

1528 

686 

50-7 

Sept. 

1380 

1496 

11 

0181 

0162 

0124 

1240 

657 

496 

Oct. 

3382 

3-494 

18 

2-249 

2082 

2  026 

1063 

586 

452 

Nov. 

2-863 

2944 

21 

2422 

2372 

2-283 

929 

532 

387 

Dec. 

0*786 

0872 

14 

0379 

0360 

0302 

425 

450 

358 

Total  or 
Mean 

23476 

24-724 

181 

L1928 

12179 

1F929 

13368 

569 

420 

For  dates  of  sowing,  etc.,  see  page  23. 

MANGOLDS,  BARN  FIELD,  1913. 

(See  "Guide,"  1913,  page  13,  Table  VI.) 


Strip. 

Strip 
Manures. 

Cross  Dressings. 

O. 

N. 

A. 

A.C. 

C. 

None. 

Nitrate  of  |  Ammonium 
Soda.            Salts. 

Rape  Cake  & 

Ammonium 
Salts. 

Rape  Cake. 

1 
2 

4 

5 
6 

7 

8 

Dung  only     ... 

Dung,  Super, 
Potash 

Complete 
Minerals 

Superphosphate 
only 

Super  and 
Potash 

Super,  Sulph. 
Mag.  &  Chloride 
Sodium 

None       i 

Tons. 
fR.  18  27 

(L.     471 

fR.  18  88 

l,L.     453 

(R.    4  24 

(L.     F47 

(R.    4  06 

(L.     F44 

(R.    3  08 

(L.     F43 

fR.    3  90 
(L.     F51 

IR.    3  08 

IL.     1*21 

Tons.             Tons. 
2905             22  19 

748               725 

2836             2928 

793                823 

{23}    l359 

1     659   1 

I     7-62  J    i         *  M 

1738               5  10 

521                410 

1434             1079 

590                5  30 

1706             1348 

633                559 

1139               442 

578               397 

1 

Tons. 
22  83 

726 

30  25 

1022 

2736 

884 

673 

508 

1952 

8'78 

20  89 

8'12 

576 

429 

Tons. 
2132 

614 

2796 

725 

21  98 

524 

825 

455 

1652 

4'92 

2002 

534 

725 

415 

R  —  roots.         L  =  leaves.         Tons  per  acre  in  all  cases. 


26 


HAY.    THE  PARK  GRASS  PLOTS,  1913. 

{See  "Guide,"  1913,  page  21,  Table  XI.) 


Plot. 

Manuring. 

Yield  of  Hay  per  acre 

1913. 

Average 
57  years 

1856-1912 

1st  Crop. 

2nd  Crop. 

Total. 

(1st  &  2nd 
crops). 

cwt. 

cwt. 

cwt. 

cwt. 

31 

12) 

Unmanured     ...          

f    12-4 
\    14'9 

06 
07 

130 
156 

20'9 
239 

2 

Unmanured  ;   Dung  8  years,  1856-63 

153 

0'5 

158 

286 

5-1 

(N.     half)    Unmanured  ;     following 

Amm.  Salts  alone,  42  yrs.  1856-97 

202 

08 

210 

144  (1) 

1 

Amm.  Salts  alone  ;  with  Dung  8  yrs. 

1856-63         

26'4 

2*4 

288 

359 

17 

Nitrate  of  Soda  alone 

266 

l-9 

28'5 

337 

4-1 

Superphosphate  of  Lime 

211 

06 

217 

216 

8 

Mineral  Manure  without  Potash     ... 

203 

10 

213 

280 

7 

Complete  Mineral  Manure 

40'6 

2-6 

432 

409 

5-2 

(S.  Half)  Complete  Mineral  Manure  ; 
following    Amm.    Salts   alone   for 

42  yrs.  1856-97 

352 

17 

369 

232  (1) 

6 

Complete  Mineral  Manure  as  plot  7  ; 
following  Amm.  Salts  alone  13  yrs. 

1856-68          

366 

38 

404 

37-2 

15 

Complete  Mineral  Manure  as  plot  7  ;. 
following  Nitrate  of  Soda  alone  18 

yrs.  1858-75              

34-8 

37 

385 

36'8 

4-2 

Superphosphate  and  Amm.  Salts    ... 

45'4 

23 

477 

335 

10 

Mineral    Manure    (without    Potash) 

and  Amm.  Salts 

44"2 

20 

462 

477 

9. 

Complete  Mineral  Manure  and  Amm. 

Salts 

560 

21 

581 

54'3 

11-1 

Complete  Mineral  Manure  and  extra 

Amm.  Salts ... 

643 

7-2 

71-5 

665 

11-2 

As  plot  11-1,  and  Silicate  of  Soda  ... 

667 

93 

760 

733 

16 

Complete  Mineral  Manure  and  Nit. 

Soda  =  43lb.  N 

42"9 

39 

46'8 

463 

14 

Complete  Mineral  Manure  and  Nit. 

Soda  =  86  1b.  N 

51-9 

3-8 

557 

569 

13 

Dung  and  Fish  Guano,  once  in  4  years 

45-4 

51 

505 

— 

(1)     15  years,  1898—1912. 


BOTANICAL  COMPOSITION,  PER  CENT. 

First  Crop,  1913. 
(See  "Guide,"  1913,  page  22,  Table  XII.) 


Plot. 

Manuring. 

Gramineae. 

Leguminosae. 

Other  Orders. 

3 
4-1 
8 
7 
6 
15 

Unmanured 

Superphosphate  of  Lime 
Mineral  Manure  without  Potash 
Complete  Mineral  Manure 
As  7,  1869  and  since 
As  7,  1876  and  since 

Per  cent. 

590 
56  9 
304 
695 
544 
637 

Per  cent. 

87 
107 
158 
153 
268 
172 

Per  cent. 

323 
32'4 
538 
152 
188 
191 

27 


WHEAT.    BROADBALK  FIELD,  1913. 

(See  "Guide,"  1913,  page  30,  Table  XVI.) 


Dressed 

Average 

Plot. 

Manuring. 

Grain. 

Straw 
per 

for  61  years, 
1852-1912. 

Yield 

Weight 

Acre. 

Dressed 

per 
Acre. 

per 
Bushel. 

(.rain 
per  Acre. 

per  Acre. 

Bushels 

lb. 

cwt. 

Bushels. 

cwt. 

2 

Farmyard  Manure      

257 

649 

296 

152 

348 

3 

Unmanured 

5*8 

63  3 

45 

126 

103 

5 

Complete  Mineral  Manure   ... 

94 

63"  8 

7-2 

145 

121 

6 

As  5,  and  single  Amm.  Salts 

142 

647 

138 

232 

214 

7 

As  5,  and  double  Amm.  Salts 

208 

658 

267 

32  1 

32-9 

8 

As  5,  and  treble  Amm.  Salts 

285 

658 

384 

366 

411 

9 

As  5,  and  single  Nitrate  Soda 

233 

616 

24-2 

— 

— 

10 

Double  Amm.  Salts  alone     ... 

113 

645 

117 

20  0 

184 

11 

As  10,  and  Superphosphate... 

134 

63  9 

146 

229 

11-  3 

12 

As  10,  and  Super  and  Sulph.  Soda 

190 

65- 1 

227 

29' 1 

280 

13 

As  10,  and  Super  and  Sulph.  Potash 

216 

65' 6 

3C>  3 

3P0 

315 

14 

As  10,  and  Super  and  Sulph.  Mag. 

195 

654 

257 

288 

280 

15 

Double  Amm.  Salts  in  Autumn,  and 

Minerals 

22*4 

656 

223 

299 

29*7 

16 

Double  Nitrate  and  Minerals 

23  9 

655 

374 

— 

— 

17  1 

Minerals  alone,  or  double  Amm.  Salts  f 

*98 

*65-0 

•9'2 

•149 

*130 

18  j 

alone,  in  alternate  years    ...          ...  I 

t217 

+657 

+31-1 

t299 

+295 

19 

Rape  Cake  alone 

198 

652 

248 

25H  (2) 

25-7  (2) 

20(1) 

As  7,  but  excluding  Superphosphate 

110 

655 

175 

~ 

*  Produce  by  Minerals.  t  Produce  by  Ammonium  Salts. 

(1)  Commenced  in  1906.  (2)  20  years,  1893—1912. 

Note. — As  in  the  previous  season  (1912),  owing  to  the  foulness  of  the  land 
on  the  upper  half  of  the  field,  the  produce  here  recorded  was  that  obtained  on 
the  lower  half  of  the  field  only.     (See  notes  on  the  crop  at  p.  7). 


WHEAT   AFTER    FALLOW  (without  manure  1851  and  since). 

HOOS  FIELD,  1913. 

(See  "Guide,"  1913,  page  44,  Table  XXI.) 


Dressed  Grain 

Straw 

Total  produce 


1913 


'   Yield — Bushels  per  Acre 
i    Weight  per  Bushel 

cwt.  per  Acre 

lb.  per  Acre 


8  3 
618 

6"7 
1284 


Average 
57  vears 
1856-1912 


160 

594 
137 
2536 


?.R 


PERMANENT  BARLEY  PLOTS.    HOOS  FIELD,  1913. 

(See  "Guide,"  1913,  page  37,  Table  XVIII.) 


Plot 


Manuring. 


lO 
20 
3  O 
40 


1  A 

2  A 

3  A 

4  A 


Unmanured 
Superphosphate  only 
Alkali  Salts  only 
Complete  Minerals     ... 

Ammonium  Salts  only 
Superphosphate  and  Amm.  Salts 
Alkali  Salts 
Complete  Minerals 


1  A  A  Nitrate  of  Soda  only 

2  AA  Superphosphate  and  Nitrate  Soda 

3  AA  Alkali  Salts 

4  AA  Complete  Minerals 


1913. 


Dressed  WJ*h< 

Grain-  J  Bushel. 


1  AAS 

2  AAS 

3  AAS 

4  AAS 

1  C 
2C 

3  C 

4  C 

7—1 

7—2 


As  Plot  1  AA  and  Silicate  of  Soda 

,,      ,,     2  AA  ,,  

,,       ,,3  AA  ,,  

„       ,,     4  AA  ,,  

Rape  Cake  only 

Superphosphate  and  Rape  Cake 
Alkali  Salts 
Complete  Minerals 

Unmanured    (after    dung    20    years, 

1852—71)      

Farmyard  Manure 


Bushels 
211 
34- 1 
254 
403 

408 
64- 1 
370 
636 

404 
60- 7 
403 
608 

507 
60' 1 

50' 1 
595 

503 
55-6 
52-9 
54-9 


42'9 
617 


lb. 

555 
569 
563 

57'5 

55-9 
57-1 
564 
573 

569 

580 
57-3 
58-1 

57-8 
576 

577 
580 

57-9 
57-0 
58"2 
583 


571 

57-8 


Straw 


cwt. 

98 

136 

123 

19'8 


21'0 
307 
209 
312 

260 
315 

25'8 
316 

239 

277 
25-8 
26'9 


17'9 
319 


Average  60  years, 
1852—1911. 


Dressed 
Grain. 


Bushels. 

127 
197 
15-2 
197 

255 
382 
280 
4P5 

29-3 
431 
300 

427 


Straw. 


cwt. 

8-4 
100 

8-8 
111 

147 
220 
169 
250 

17-8 
26-3 
193 

27-3 


328  (1)  197  (1) 

423  (1)  260  (1) 

352  (1)1  217  (1) 

43-6  (1)  277  (1) 


383 
405 
369 
40'5 


24-8  (2) 

47T 


221 
236 
223 

24'5 


148  (2) 
296 


(1)  48  years,  1864—1911.  (2)  40  years,  1872—1911. 

Note. — The  whole  of  the  above  plots  were  fallowed  in  1912 

BARLEY.    HOOS  FIELD,  1913. 

(See  "Guide,"  1913,  page  43,  Table  XX.) 


Manures  applied 

Dressed  Grain. 

Total 

Plot. 

to  the  Potatoes, 

Straw 

Produce 

1876-1901. 

Yield 

Weight  per 

per  Acre. 

per  Acre. 

Unmanured  since. 

per  Acre. 

Bushel. 

Previous  Cropping:   Potatoes,  1876-1901;   Barley,  1902  and  IS 

»03  ; 

Oats,  1904  ;  Barley,  1905-1911 ;  Oats,  1912. 

Bushels. 

lb. 

cwt. 

lb. 

1 

Unmanured 

18-4 

566 

9  2 

2093 

2 

Unmanured  1882  to  1901, 

previously  Dung  only 

256 

57-2 

122 

2854 

3 

Dung  1883  to  1901     

342 

57'3 

173 

3930 

4 

Dung  1883  to  1901     

337 

571 

173 

3896 

Pr< 

ivious  Cropping:   Potatoes,  1876-1901;  Barley,  1902-1903;  Oats 

i,  1904  ; 

PI 

3ts  5,  7,  9,  Cow  Peas  (failed),  1905;  Plots  6,  8,  10,  Red  Clover 

1905; 

1906-1911,  all  Plots  Red  Clover;  Oats,  1912. 

5 

Ammonium  Salts 

29  0 

56-6 

138 

3205 

6 

Nitrate  of  Soda 

30'6 

563 

139 

3302 

7 

j  Ammonium  Sails  and               | 
1  Mixed  Minerals        

442 

570 

209 

4889 

8 

1  Nitrate  of  Soda  and                  | 
i  Mixed  Minerals        i 

43    i 

572 

201 

4761 

9 

I  Superphosphate          

33'9 

56'8 

158 

3725 

10 

•  d  Minerals 

359 

57'2 

lo  6 

29 
LITTLE  HOOS  FIELD,  1904-1913. 

RESIDUAL   VALUE  OF  VARIOUS  MANURES. 

(See  "Guide,"  1913,  pages  45—47.) 


TOTAL   PRODUCE 


-Grain  and  Straw,  or  Roots  and  Leaves,  per  acre, 
1908  and  since. 


Series 

Man- 

and 

Manuring. 

Swedes 

Barley 

Wheat 

golds 

Wheat 

Swedes 

Plot. 

1908. 

1909. 

1910. 

1911. 

1912.* 

1913. 

Tons. 

lb. 

lb. 

Tons. 

Bushels. 

Tons. 

A  1 

Unmanured 

140 

3792 

2270 

116 

194 

86 

2 

Dung  (ordinary),  1904,  '8  &  '12 

19  1 

5128 

2572 

139 

343 

81 

3 

1905,  '9  &  '13 

145 

5544 

2681 

14-1 

269 

83 

4 

1906  &  1910 

155 

4057 

2406 

125 

29-2 

1'8 

5 

1907  &  1911... 

173 

4581 

2358 

158 

268 

69 

B  1 

Dung  (cake  fed),  1904,  "8  &  '12 

224 

5362 

2386 

141 

356 

8-6 

2 

Unmanured 

143 

3862 

2261 

120 

21*8 

7-8 

3 

Dung  (cake  fed),  1905,  '9  &  "13 

142 

6641 

2921 

142 

294 

66 

4 

1906  &  1910... 

169 

4400 

3502 

144 

265 

15 

5 

1907  &  1911... 

190 

4298 

2369 

17  1 

314 

2'8 

C  1 

Shoddy,  1904,  1908  &  1912     ... 

197 

3969 

2295 

114 

284 

9-4 

2 

1905.  1909  &  1913    ... 

163 

4558 

2387 

116 

261 

107 

3 

Unmanured 

151 

3850 

2561 

117 

24-2 

79 

4 

Shoddy,  1906  &  1910 

191 

4466 

3461 

140 

304 

56 

5 

„       1907  &  1911 

222 

5448 

2560 

147 

298 

7-2 

D  1 

Guano,  1904,  1908  &  1912      ... 

209 

3608 

1742 

105 

288 

7-5 

2 

1905,  1909  &  1913      ... 

153 

6834 

2114 

115 

241 

107 

3 

1906  &  1910     

159 

4053 

3392 

111 

225 

7-4 

4 

Unmanured 

174 

4510 

2739 

118 

269 

6"6 

5 

Guano,  1907  &  1911     

157 

4014 

2374 

142 

263 

6"8 

E  1 

Rape  Cake,  1904,  1908  &  1912 

197 

3750 

2180 

107 

277 

8'1 

2 

1905,  1909  &  1913 

151 

5203 

2242 

1U7 

22-3 

55 

3 

1906  &  1910 

145 

3866 

3486 

115 

22-2 

67 

4 

1907  &  1911 

152 

4661 

2516 

145 

251 

7'1 

5 

Unmanured 

147 

4155 

2784 

127 

211 

70 

F  1 

Unmanured 

141 

4814 

3166 

8"7 

3T6 

6'4 

9 

Superphosphate.  1904,  '8  &  '12 

169 

4726 

3223 

109 

334 

8"2 

3 

1905, '9&'13 

146 

4973 

2922 

1T7 

319 

86 

4 

1906  &  1910... 

160 

5280 

2682 

12'8 

349 

6'2 

5 

1907  &  1911... 

164 

5641 

3190 

142 

354 

64 

G  1 

Bone  Meal,  1904,  1908  &  1912 

167 

4445 

3345 

99 

328 

7"5 

2 

1905.  1909  &  1913 

143 

4922 

3657 

9-9 

327 

74 

3 

Unmanured 

12'7 

4247 

3701 

9'2 

290 

35 

4 

Bone  Meal,  1906  &  1910 

142 

4711 

3263 

105 

318 

39 

5 

1907  &  1911 

199 

5285 

3512 

126 

344 

5-8 

H  1 

Basic  Slag,  1904,  1908  &  1912 

138 

4182 

3564 

115 

357 

63 

2 

1905,  1909  &  1913 

136 

4530 

3596 

120 

337 

66 

3 

1906  &  1910 

136 

4431 

3943 

12'5 

29- 1 

34 

4 

1907  &  1911 

144 

3860 

3804 

120 

325 

31 

5 

Unmanured        

U-4 

4511 

4005 

105 

30-1 

2-2 

The  yields  on  the  plots  to  which  the  manure  was  applied  in  any  given  year  are  printed  in  heavier  type 

*  Dressed  Grain  only. 


30 


COMPARISON  OF  THE  YIELD   PER  ACRE  OF  OATS  AND  BARLEY 
GROWN    TOGETHER,   AND   EACH    ALONE,   WITHOUT   MANURE, 

AFTER  SWEDES. 

SAWPIT  FIELD,  1912. 
LITTLE  KNOTT  WOOD  FIELD,  1913. 


Plot. 

Crop. 

Dressed 

Grain. 

Total 

Yield. 

Weight 
per  Bushel. 

Straw. 

Produce. 

1912. 

Bushels. 

277 
173 
362 

1913. 

1912. 

1913. 

1912. 

1913. 

1912.        1913. 

1 

2 
3 

Oats  and  Barley 
Oats  alone 
Barley  alone 

Bushels. 
26'2 
197 
324 

lb. 
49  0 
331 
505 

lb. 
505 
412 
536 

cwt. 
263 
26'4 
26'8 

cut. 
152 
122 
18"4 

lb. 

4318 
3593 
5081 

lb. 
3046 
2200 
3800 

CHALKING   EXPERIMENTS. 

BARLEY  (Plumage  Cross.) 

LITTLE  KNOTT  WOOD  FIELD,  1913. 


Dressed  Grain. 

Straw. 

Total 

Yield. 

Weight 
per  Bushel. 

Produce. 

Unchalked 
Chalked  ... 

Bushels. 
59 '4 
68-2 

lb. 

54-5 
546 

cwt. 
241 
266 

lb. 
5994 
6760 

Both  plots  manured  with   £  cwt.   Sulphate  Ammonia  and  2£  cwt.  Superphosphate 
per  acre. 


A  GENERAL  Account  of  the  Rothamsted  Field  Ex- 
periments is  given  in  The  Book  of  the  Rothamsted 
Experiments,  by  A.  D.  Hall,  M.A.,  price  10/6  (John 
Murray). 

A  short  summary  is  given  in  The  Guide  to  the 
Rothamsted  Experimental  Plots,  2nd  Edn.,  1913, 
price  1   -  'John  Murray). 


31 


Lawes  Agricultural  Trust. 


TRUSTEES. 


Right  Hon.  A.  J."BaITour,  P.C.,  F.R.S.,  M.P. 

J.  Francis  Mason,  Esq.,  M.P. 

COMMITTEE  OF  MANAGEMENT. 


Sir.  J.  H.  Thorold,  Bart.  LL.D. 

{Chairman) . 
Dr.  H.  Miiller,  LL.D.,  F.R.S. 

(Treasurer). 
Prof.   H.   E.  Armstrong,  LL.D., 
F.R.S. 


Prof.  R.  H.  Biffen,  M.A.,  F.R.S. 
Dr.  H.  T.  Brown,  LL.D.,  F.R.S 
Prof.  J.  B.  Farmer,  M.A 
Dr.  A.  B.  Rendle,  D.Sc, 
Dr.  J.  A.  Voelcker,  M.A. 


F.R.S. 
F.R.S. 
Ph.D. 


The  Incorporated  Society 

for  Extending  the  Rothamsted  Experiments 

in  Agricultural  Science. 


MEMBERS  OF  COUNCIL. 


His  Grace  the  Duke  of  Devonsh 
J.  F.  Mason,  Esq.,  M, 
Prof.    H.   E.  Armstrong,    LL.D., 

F.R.S. 
Prof.  K.  H.  Biffen,  M.A.,  F.R.S. 
Dr.  H.T.  Brown,  LL.D.,  F.R.S. 
The    Right    Hon.    Sir    John    T. 

Brunner,  Bart.,  P.C. 
The  Most  Hon.  the   Marquess  of 

Lincolnshire,  K.G.,  P.C. 
Prof.  J.  B.  Farmer,  M.A.,  F.R.S. 
Robert  Mond,  Esq. 


ire,  P.C,  G.C.V.O.  (Chairman). 

P.  (V ice-Chairman) . 

Capt.  J.  A.  Morison. 
Dr.  Hugo  Miiller,  LL.D.,  F.R.S. 
(Treasurer). 
Sir  W.  S.  Prideaux. 
Dr.  A.  B.  Rendle,  M.A.,  D.Sc, 

Sir  j.  H.  Thorold,  Bart. 

Dr.  J.  A.  Voelcker,  M.A.,  Ph.D. 

J.  Martin  White,  Esq. 

E.  J.  Russell, 

Hon.  Secretary. 


32 


Subscribers  and  Donors 

to  the  Rothamsted  Experimental  Station, 

1904  and  since. 


The  Goldsmiths'  Company 

(Endowment  for  Soil  Investigation). 

J.    F.   Mason,    Esq.,  M.P.     (The 
"James  Mason"  Laboratory). 

The  Chilean  Nitrate  Committee. 

The     Permanent     Nitrate    Com- 
mittee. 

The  Fertiliser  Manufacturers'  As- 
sociation. 

The  Potash  Syndicate. 

The  Sulphate  of  Ammonia  Com- 
mittee. 

The  Nitrogen  Fertilisers  Ltd. 

The  Clothworkers'  Company. 

The   North  -Western    Cyanamide 
Company. 

A.  D.  Acland,  Esq. 

The   Right   Hon.  Lord  Avebury, 
F.R.S. 

Capt.  Clive  Behrens. 

Messrs.  F.  W.  Berk  &  Company. 

The  Right  Hon.  Lord  Blyth. 

A.  Brassey,  Esq. 

J.  F.  L.  Brunner,  Esq.,  M.P. 

The    Right    Hon.    Sir    John    T. 
Brunner,  Bart.,  P.C. 

C.  A.  J.  Butter,  Esq. 

Sir  E.  Hildred  Carlile,  M.P. 

W.  T.  Coles,  Esq. 

Sir  K.  P.  Cooper,  Bart. 

II.  Shepherd  Cross,  Esq. 

II  is  ( i  race  the  Duke  of  Devonshire, 

p.( .,  G.c.y.o. 

Harold  W.  Drewitt,  Esq. 

Messrs.  Ellis  &  Everard. 

Sir  John  Evans,  K.C.B.,  F.R.S. 

Sir  Walter  Gilbey,  Bart. 

Sir  Eustace  Gurney. 

Sir  A.  Henderson,  Bart. 


H.  Tylston  Hodgson,  Esq. 

A.  B.  Holinsworth,  Esq. 

A.  Howard,  Esq. 

The    Right    Hon.    Lord    Iveagh, 

K.P.,  G.C.V.O. 
Messrs.  W.  B.  Keen  &  Company. 
H.  H.  Konig,  Esq. 
Sir  Charles  Lawes-Wittewronge, 

Bart. 
Col.  H.  Mellish. 
R.  Mond,  Esq. 
Capt.  J.  A.  Morison. 
W.  Morrison,  Esq. 

A.  Mosely,  Esq. 

Dr.  Hugo  Miiller,  F.R.S. 
Henry  S.  Nunn,  Esq. 
E.  Packard,  Esq. 
Marlborough  R.  Pryor,  Esq. 
G.  Radford,  Esq. 
William  Ransom,  Esq. 
The  Right  Hon.  Lord  Rothschild, 
G.C.V.O. 

B.  S.  Rowntree,  Esq. 
Frederick  Seebohm,  Esq. 
Hugh  E.  Seebohm,  Esq. 
Edward  Speyer,  Esq. 

B.  Stanier,  Esq.,  M.P. 

G.  Stephenson,  Esq. 

Messrs.  Sutton  &  Sons. 

Dr.  J.  Augustus  Voelcker,  M.A. 

Messrs.  Walter  Voss  &  Company. 

Phillip  F.  Walker,  Esq. 

The   Right.    Hon.   Lord  Walsing- 

ham,  F.R.S. 
Sir  J.  Wernher,  Bart. 
J.  Martin  White,  Esq. 
T.  Wilson,  Esq. 
W.  K.  Woolrych,  Esq. 


And  tin-  subscribers  to  the  Lawes  and  Gilbert  Centen 


:u  y  Fund,