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New York, N. Y. Medina, O.
Athens, Ga. Berkeley, Cal.
Copyright 1918, by the Barrett Company
MAV 10 1918 ©GI.A49725.'>
^ Sweet Potatoes
^TT^ 111-] swi'ft ])ot;it() is. so far as \vt' know, a native of Aiiicrica. It was t'ouinl
y'i'(»\viii;i' lu'i't' Aviicii the early colonists arrived ami lias eontiinied to iii-
ereaso in vohnne and in favor as a food crop, lieinji' of tropieal origin, it
api^ears most extensively in the Southern States, where it is ;:ienerall.\' used and
ajipreeiated : in faet. <dl tlirou<ih tlu^ South the term "'jiotato"" usuall\' means
the sAveet potato, the white potato heiii^' distinjiiiished as the Irish or round po-
tato. Certain varieties of sAveet potato are also called '"yams'" in the South
and the name is now in <:'eiiei'al use, altliou^h histoi'icall.\' a ditl'erent family
g:rowin>r in the East Indies and the Philippines has the earlier (daim to the
The sweet potato was a valued asset in oui' war of the Revolution, for his-
tory I'elates that (Jeueral Fi'ancis .Marion, the ""Swamp Fox" of South Carolina,
maintained his men for months at a time on little else. When a Hritish envoy
came to ti'eat with him. he was invite<l to sliai'e this i-ation. and returning re-
ported to his commander. Loid Cornwallis. that i)atriots so resourceful and
self-den.\in;^' could nev<'i' he defeated. A;iain. in the wai' of 1812, General An-
di-cw .Ia(d<son. in his campai^'n a^zainst the Spmnsh in l*'lorida and Alabama and
against the I>i'itisli in Louisiana, had hut little food for his men except sweet
potatoes. When the lii'itish <:eneral. l*a(d<euham. commaiidiiii:- at New Oi'leans.
learned this, he rcjxuted home in sulistauce that the Americans never would he
eouipiei-ed hecause of their det cMH iua t ion and hecause they could alwa\s raise
enough sweet i)otatoes. on which food they could \\)i\\\ indetinitely.
Sweet Potatoes and Yams
The sweet potato is I'apidly gaining in favor and bids fair to become a food
crop of national importance. It is easy to grow, the yield per aCre is large, it
may be prepared in many attractive and palatable forms, and it has a high food
value. It should constitute a large and permanent part of our diet, but despite
its advantages the sweet potato has not received the attention of either pro-
ducer or consumer that it deserves. In the South, wiiere the crop flourishes and
where most of it is grown, the production is as yet insufficient and the quantity
in storage does not adequately supply the local markets.
Food Value. Table I shows why the sweet potato is of high food value.
Its water content is low and it contains a considerable proportion of the
energy-producing materials — sugar and starch (carbohydrates). When first
harvested, starch forms from one-sixth to one-quarter of the potato, but after
a period of storage, much of it turns to sugar, which accounts for its charac-
teristic taste and name. Energy, or heat value, is usually measured in calo-
ries. A pound of yams produces 570 calories as compared to 375 for the
TABLE I. From "Feeds and Feeding," Henry.
Production — Three pecks per capita. In 1917 953,000 acres were planted
to sweet potatoes in tlie United States. The yield was 87,141.000 bushels with
a total farm value of $96,121,000. This yield provided only 0.85 of a bushel, or
a little over three pecks per capita per annum.
Climate and distribution. The climatic conditions best suited to cultiva-
tion of the sweet potato are moderate rainfall through the growing season,
warm nights and plenty of sunshine and a period of growth free from frost
for at least four and one-half months. They are profitably grown as far north
as forty-five degrees latitude. New^ York State and Michigan grow them suc-
cessfully. Canada (Toronto section) has grown them on a small scale.
Prolific. The sweet potato is one of the most prolific of crops, a quality
tliat is particulai'ly important on the poor cotton or tobacco soils. Tender
the ordinary system of cropping, land that will produce 20 bushels of corn
•or half a bale of cotton, will produce 200 bushels of sweet potatoes. On the
farm of the South Carolina Station, Prof. T. E. Keitt obtained an average
of 250 bushels per acre with fifteen varieties. AVith intensive feitilization and
cultivation, yields of 500 to 700 bushels per acre have been obtained.
SWEET POTATOES AND YAMS
A friablr or loaiiix' soil is licsl suited to its iicrds. but aii\' w cll-di-jiiurd
soil of inodcrate I'ciiility will ])r()(lucc a jzood fco]), j)rovidt'd it is not too
cold. The sweet potato is siiii|)ly au enlarged toot, so that the soil plays a
\vv\ iuipoi't aiil pait in its de\ flopnicnt . If it is t()o loose and deep the roots
luive a teiideiu-y to leiij;tlien with a eousecpient shrinkiii^^ in diameter. A
stitT (day is not desirable but ean be inipioved b\' tui-niu','' undei" i^^reen crops,
and shoulil then produce a satisfactory yield.
Preparation of soil. The preparation of the soil invoUcs the same j^eneral
principles as does the piolitable iirowiu"!' of any ci'o|). namely, care and
thorou<ihness. The soil is bi'oken to a depth of from six to ten inches and
well liari'owed. A furrow is then ojiened. the fei-tilizei's applied and bedded
on. Later a liylit harrow or drai;' is passed over it befoi'e setting the plants.
Bedding potatoes — Home grown plants best. .Most farmers can bed
enou^ih sweet potatoes to pi'oducc theii' own j)lants at home. It has been
demonstrated that honu' ^-I'own plants will ])i'p<luce a bettei- yield than
plants of the same \ariety J:■ro^\■n undei' different conditions. There are vari-
ous methods of beddin<: followed with success in ditl'erent rejrions. The wis-
est course is to adopt the method advised by the State Experiment Station
for a jjiven locality. Tlie plants should be diawii from the bed and planted
oid\ aftei" all dan;^'ei' of frost has passed.
Time of setting plants. The (leor-iia Station has found that the best
yields are obtained if plants aie set between Ma\' Kith and .lune 11th. TIk^
same vai'ieties of potatoes planted befoi'e or aftei' these dates did init pro-
duce as heavil\-. Local conditions will larji'ely determine this cpiestion for
the indi\idual. «
Rotation of crops. It is well to renu'inber. at this point, that it is not
advisable to jirow sweet potatoes continuously on tiie same land, since that
l)ractisp. if followed. ustui11\' I'esnlts in a disease infested soil. This condition
can be lai";.;cly eoidrolled by i-otation. say. with coi-ii. |)eanuts and ji'rass.
Spacing. The usual practise in spacintr jilants is to place them in I'ows
three feet apart with from ei;jh1een to twenty-four in(dies Ix'tweeu jdants in
Setting plants. If mori' than two or thi'ee acres of potatoes are «:rowu.
it may be advisable to use a transplanter. These nnudiines are efficient and
inexpensive. With a team of mules and three men to operate it a transjilanter
often sets four acres a day Avhile sixteen men would be needed to cover the
samc^ frround plantin>jr by hand.
SWEET POTATOES AND YAMS
Fei-tilizers are an important factor in i-aising profital)!*' crops. It is almost
impossible to produce the smooth, well-shaped potato Avhich the market
requires without using a sufficient quantity of a balanced ration of plant
foods. It lias been noted, however, that an oversupply of vegetable mat-
ter in the soil or an excess of nitrogen in the fertilizer will affect the quality
of the potato and sometimes cause it to crack. It is desirable therefore that
the ingredients of the fertilizer be proportioned with due allowance for the
qualit}^ of the soil.
Amount of fertilizer. An application of stable maiuire alone lias not
been found satisfactory. At the New .Iers(\^' Experiment Station comparisons
were made Avith the use of commercial fertilizers and stable manure. Com-
mercial fertilizers produced a good crop, but a combination of the fci-tilizcr
and manure produced a higher yield than when either was used alone. It is
generally considered that the sweet potato crop can utilize a heavy amount of
fertilizer. An application of from 600 to 1,200 pounds per acre, depending
upon the condition of the soil. Avill be found profitable un<b'r most conditions
and should be supplemented- with sonu^ stable manure.
Formulas. The Georgia Station recommends a general formula containing
approximately 8 per cent, of phosphoric acid, 5 per cent, of ammonia, and 8
per cent, of potash, which may be made up as follows:
Acid phosphate (16 per cent.) 1,000 ])ounds
Sulphate of ammonia 350 "
Cottonseed meal 250
Sulphate of potash r?00
J. H. Beattie of the U. S. Department of Agriculture recommends the
following as a good mixture for sweet potatoes :
Sulphate of ammonia 250 ponnds
Dried blood, 200 pounds, or fish-scrap HOO
Acid phosphate (11 per cent.) 1,200
Muriate of potash 400
Either of these formulas is good for general use when it is possible to ob-
tain potash at a reasonable price. Under present circumstances the potash fig-
ure in the first formula should be changed to 3 per cent, in place of 8, a part of
this coming from the cottonseed meal : the proportion of nitrogen should also
be varied to suit the soil type.
2,000 pounds per acre profitable. ]\lan\ potato growers have used as much
as 2,000 pounds of commercial fertilizer per acre with highly profitable re-
sults. Potash, which we are now forced to leave out of consideration, has for
a long: time been considered the most essential element for potatoes. Profs.
'^xperiiiu'ut Made by II. U. MiUln-ll, .\tlnii-~. (..i
Tliis oxpcriiiu'iit was made on a red clay ln.iiii thai had pri'viiiusl.v liet-ii sown in small snihi
lollowed liy fowpeas. The yield of potatoes from the unfertilized plot was siuall and nearly un-
MiarkctMldf. while the seeond [dot. with pliosphate and potash only, was lint little lictter. Most of
ilhisi' li-imi the Sulpliate of Auimonia plot were of umid niMrketaliie unalily.
Diigj^ar ami Williamson of the Alabama Station, however, make tht- following
.statcuu'iit, based on tests on heavy soils:
"Taken as a whole, tiiese experiments seem to imiicate tliat the pojjiilar
idea tliat potasli is the most important eonstitiimt in a fert iji/n- Wm sweet
poti'.toes is ineorreet, at least as to pi'aetieallv all the soils here repi'esented.
On the other haiul, these tests sliow that phosphate and nitroj^en were mnclr
more impoi'tant than potash.
"Tlie.se experiments also seem to discredit the notion that the use of a
fertilizer containing nitrogen causes the sweet potato plant to run to vines to
an injurious extent. In our experience this danger does not occur where
reasonable amounts of nitrogen are used in combination with acid phosphate."
Experiin 111 1 W . L. la.vlor, Midluiul, (ia.
'rhe soil was a cray. sandy loam, typiial of Sonth Ceor^'ia or Ilie lo.istal pl.iin. Hotb plots
ha<l reielved aliont MM) pounds per aere of a r_'--_'-0 fertilizer. Sulphate of .\mmonia at the rate of
HKt pounds per a' re was applied .Tune 1st. The yield was donliled and the .|iialitv of the pota
loes reoelviniit tl "nlphate of .\mnionia w.as far better.
SWEET POTATOES AND YAMS
Top-dressing sweet potatoes. Successful growers have generally adopted
the practise of top-dressiiig their sweet potatoes with some quickly available
nitrogenous fertilizer. By applying from 100 to 150 pounds of Sulphate of
Ammonia per acre at the second cultivation, they obtain substahtial increases
Sulphate of Ammonia. The Florida Experiment Station found wlien com-
paring the value of Sulphate of Ammonia and dried blood as ingredients of
complete fertilizers, that Sulphate of Ammonia gave the better yield. Mr.
J. R. Davis of Bartow, Florida, a well-known and successful sweet potato
grower recommends it for this crop. The illustrations on the preceding page
show the results of field tests with SulpJuite of Ammonia apjilied as a top-
dressing and figures 7 and 8, at time of planting (see page 15).
Harvesting SAveel Potatoes.
A typical scene near Savannah. Ga. The vines have been cut and are lieins hauled away to
he fed to live stt)ck. The potatoes are being- plowed from the sdH and carefully sorted into piles
and baskets before l)eini;' hauled to the storage house.
CULTIVATION AND HARVESTING
The cultivation of sweet potatoes does not differ in any essential way
from that of any other farm or garden crop. Any of tlie ordinary farm tools
employed to maintain a mulch may be used at intervals of from seven to ten
days and particularly after each rain. Cultivation should begin soon after the
plants are set and be kept ujo until the vines arc large enough to interfere
with the work. After the vines begin to run they sliould be turnetl into every
other middle to facilitate cultivation and then returned into the cultivated
middles while the work is completed. At the last cidtivation as much soil
as possible shotdd be thrown to the row in order to leave the plants in hills.
Harvesting. Theic is little use in raising a ero}) unless it can be utilized
to best advantage. Tlius, upon the care exei-ciscd in harvesting sweet pota-
toes depends, to a considei-able degree, tlie success wliieh may be expected
in storing them. Usually, it is desii-able to harvest as early as possible in
SWEET P () T A T () K S AND Y A M S
ordfi' to tiiUf iiilvaiit;i<^r ot" t';i\()i;il»lf pi'iccs. hut it is iifccssiiry to iivoiil *\\<i-
'^liiii:. tile crop whilf still iinniiit iii-c Itrcjiiisr ot' tlif i'oiisf(|iH"iit (|<'ci-c;isr ill hotli
yield and k»'t'piii<>- (piality. A rule o" tlmiiih. wliicli lias jjiovcd lirlpfiil, is
to liafvcst at least ten da\s hci'ort' the avcrajic date of t'rce/iiij:'. iiiasiiiucli as
sevcic injury is (H-rtaiii to occui- if the potatoes are still in tin- vroiinil wlifii
the first frost eonies on. 'Phi' ero|) should he harvested wIk-ii the soil is dry.
I'or it" the woi'k is done in wit weather eai'th will adhere to the potatoes and
tlie.\ are liahle to rot. Where |)otatoes are raised on a small scale the oi'dinary
iiiidilh' hiister is often used to throw the i-oots out of the f;round. If l;irj;ei'
areas are <:i'own a potato di<i'<>'ei' ina.\' well l)e used. i\e^'ai"dless of the iiiethods
of harvestinji', <>reat caie should he taken to prevent l(i-uisin«i' or eiittin;^- the
tuhers, and any thus injured should l>e sorted and inuiiediately sold on the local
market or fed to live stock. They should never he .stored oi- shipped to a dis-
tant market as they will not keej).
Pool" storajze facilities in the South, where most ol' our sweet |)otatoes
aie jirown. ai'e the <ireatest ohstaele to increased production. II. ('. Thomp-
son, of the r. S. Departnuuit of Ajii'icult ui'e. estimates that from 20 to ')() ]>ei'
cent, of the potatoes stoi'ed in hanks or i)its in the Southern States sp"ii ir
are of an inferior (piality. This is a difticulty that heai's most heavily on the
smaller fi'rowers. An ordinary type of pit is show n in tiji'ure 4. For a numher
\n <)r<liii;M\ Nx\eei I'otato I'it.
■rills mctliiMl of stor.it'"' is tlio reason why iiciuly li;Uf of the swoot jiotatiK's irniwii in llu-
S.iutli «'V«,'ry yi'ar arc lost l>y rot. 'riu' av«'i-a}.'(> Sonilit>rii fariiicr proihircs i-noii;;li swi-ol potatoes
lo supply Ills family iifcds tliroiiRli the wliilcr lull liy sin'liiir tlio loss is so lioavy tlial lie lias not
iMioiit'li ii'I'l lo liril fell- plants for iioxt season.
<d' small <:rowei's these methods are possihly the only practicahle ones.
They can he made i"eas(Mialily safe, howevei-. if proper cai'e is taken that the
potatiM's are t horout!hl\' dr\ when stored and that the hank is kept di-y. proji
A Good Storage Pit.
'I'liis is a jioiid typL' 111' small storage pit for bousiug' sweet potatoes. Aiiiple proxisioii Jjas
licfii luatle to protect the potatoes from rain, to keep them dry, and for veiitil.ntioii. Small
loss by rotting occurs when pits are built with these provisions.
eiiy ventilated, and warm. A better type of pit is shown above. The
specially designed storage house, however, is by far the best method. Sevt^'al
types of houses have been developed in different sections, and their use by large
growers and by communities of smaller growers is increasing. In fact, ac-
cording to Prof. H. P. Stuckey, of the Georgia Station, taking it year i.; and
year out, sweet potatoes cannot be grown and stored at a profit unless some
such storage house is pi'ovided. A satisfactory type is shown below. The
liouse is provided with artificial heat and air-circulating passages so tluit tlie
potatoes can be cured for a week or so at about 90 'F., and tlit^ tempei-atiii-e
then maintained constantly at 50'^ to 60'^F. Full ])lans for such houses nvo
given in Bulletin 548, U. IS. Department of Agriculture.
A ('oniiminit> Stoi'aj;e House.
'I'his large storage house was liuill liy Mi. .lolni I), .\rcliil.ald at Tlioniasville, Oa.. not to
accommodate his own needs alone but to help the small growers in the community and to encour-
age the industry. These houses are neither expensive nor difficult to build and they aid
the '■ommunity by helping to conserve its food supply.
SWEET POTATOES AND YAMS
S^veet potatoes «^r(i\vii lOi- early iiiafUct are harvested, j^ratled. paekecl.
aiitl usually shipped the same (la\ . Wliei-i- pioper storage faeilities have been
]>i-ovi(le(l, potatoes are dried in the tield. j;-raded. and placed in storage for
\\in1e]' and spring shipment. They iiia.\ he safely shipped in barrels, crates,
and ham])ers. Itiit not in l»nlk or in sacks as they are <'asily hi'uised. thereby
Thei-e are a great many varieties of sweet |)olat()es grown in the I'nited
States and all dilVer, iin)i'e oi' less, in yiekl. tiavoi-. shape, color and earliness
of maturity. Prof. Stuckey writes: "The variety to be grown depends upon
the purpose for which the potato is to be used.
Northern demand, "n' a grower wishes to suppl\ the .Xorthei-n market he
should select a potato that has a light coloi-ed tlesh and is dry and mealy
when cooked. To the average Noi-thiM-n famil\- the ideal potato is the Irish
potato. The nearei- the sweet ])()tato approaches the hisli potato in texturi'
and flavor, the nnn-e salable it will be on the Northern market.
Southern demand. "In the South the demand is ditf'ei-ent. To the average
Southei-n family a potato with a rich, \ellow Hesh and a \-ery swi'et flavor is
preferred. A potato that has a candied appearance after baking, as though
it had been dipped in cane siru]). is ideal for the Southern market."
The Jersey Yellow or Yellow Nancemond. Triumph and Red Jersey are
typical of the dry mealy varieties belonging to the first class. The Pumpkin
Yam, Providence. Nancy Tlall, Porto Rico Yam and riolden Beauty represent
the yellow, moist, sweet varieties that are popular in the Southern markets.
For feeding to live stoek such \arielies as Kiuu-mous. Triumph and SouthiMMi
Queen ai'e suggested.
FEEDING VALUK OF SWEirr POTATOES
FOR LIVE STOCK
The principal use of the sweet potato is for human food but this is by no
means its only importance. The roots and vines make excellent feed for live
stock. The South, which fails to proiluce enough corn and hay for its own con-
sumption, can use the sw(M>t potato more largely as a supidenu-nt to its feed
production fiom Septend)ei- to Jannai-y. The Southern farmer is interested in
finding a cheaper and nH)re pi-oductive source of carl)ohydrates than corn, and
the sweet potato tills the need, it is one of the best yielding of the Southern
grown root crops. All kinds of live stock seem to be fond of both roots and
vines. It is estimated that three bushels of sweet potatoes are equal to one
bushel of corn, ami the Florida Experiment Station states that when a ration
of oncJialf sweet potatoes and one-half grain was fed to work stock, better
results were obtained than with a whole grain ration and at a lower cost.
SWEET POTATOES AND YAMS
Sweet potato silage vs. corn silage. The same station finds that silage made
I'l'oiii sweet ])otatoes is equal in nutritive vahu' to nearly twice the quantity of
corn sila<^e. Comparing results ol)taiiU'd from these two crops he says: "Ex-
perience in feeding these two silages has been that 100 p®unds of sweet
potato silage will replace from 150 to 200 pounds of corn silage in the ration.
This, no doubt, is due to the fact that tlu' sweet potato silage contains less
water and two and a half tiuu's as luucli nitrogen-free extract as the corn
Sweet potato silage for milk. They investigated the relative values of
sweet t)()tato and sorghum silage in milk production and found that the former
gave better yields. The cows on the potato ration produced 307 gallons of
milk, wdiile those on sorghum made 281 gallons. It is pointed out that "One
noticeable tfact in this experiment is that the cows ate one-third less sweet
potato silage than sorghum silage. This is quite a saving in the amount of
feed consumed by a herd during the year."
Vines as a feed for live stock. Sweet potato vines make an excellent
soiling crop for all live stock. It is rathei" difficult to cure them, so the best
results are usually obtained by feetling them when still green. They are
nutritive and rank high even in comparison with legumes. In Table II Avill
l)e found an analysis made by Prof. Keitt of the South Carolina Station giving
the average from four of the common varieties of sweet potatoes, as compared
wdtli ha}^ from red clover, crimson clover, cowpeas, and soy-beans.
(Water-free) Protein Fat Fiber Ash N-free extract
Red clover hay
Crimson cloNiT hay
Average 16.82 3.83 26.76 8.34 44.25
Sweet potato vines 12.48 4.86 18.22 8.73 55.71
CANNING S\VP:ET POTATOES
The canning of sweet potatoes is assuming the importance of an industry.
although more attention has been paid to it in the North than in the South.
Each year many cai- loads of eaniied ]iotatoes are shipped from the North to
the South, possible only because a large part of the Southern crop is annually
lost or wasted. Canning is receiving more attention in the South but not as
much as it deserves. Tiu' process is not a difficidt one and every family in rural
eommuinties where the cro]-) is grown should preserve a s\ipply for the winter
SWEET POTATOES AND YAMS
111 lulditioii to the familiar methods of j)r('i)iiriii^- sweet potatoes, there
are a few that arc espeeially adapted to tlie moist, sweet. Southern vai'ieties.
This is prol)ably tlie most favored metiiod of cookiiijr sweet potatoes.
Partially cook in boiling- water. Cool. peel, and slice one-fourth to one-third
inches thick lengthwise of the potato. Place in layers in a hakiiig-dish. Make
a simp of tlie sugar, water, lemon juice ami cinnamon and cook it for about
ten minutes. Pour this sirup over the layers of potatoes, place in a moderate
oven, and cook until the potatoes are gummy. A few marshmallows may be
added a few minutes before removing from oven.
1-2 dozen sweet potatoes 1 teaspoon ful cinnamon
2 cups sugar 1 teaspoonful salt
1 cup hot water 1 tablespooiiful lemon juice
2 ounces butter
Sweet Potato Custard
Line a pie-tin Avith pastry and till with a mix-
ture of 2 cups mashed potatoes. 1 cup sweet uiilk.
2 eggs, 1/) cup sugar. 2 ounces butter. 1 teaspoon-
ful grated lemon-rind, and a little salt. Bake as
'* 'Possum an' Taters"
To the Southern negro there is no more
tempting delicacy than " 'possum an" taters." an<l
the richest humor in the folklore of the race is to
be found in the ancient tales which have been
handed down alxuit it. Rut only the "oP colored
mamiiiN." and we have her still, knows the se-
ei'ets of the dish when made as it should be made.
SWEET POTATOES AND YAMS
In Table III will be found the acreage production, and total farm value
for the more important sweet potato states. The South grows practically
all the sweet potatoes, about 90 per cent, of the total. Tlie only important
producer among the northern states is New Jersey, which also plants the
largest acreage per farm.
Acreage, Production and Total Farm Value by States, 1917.
Acreage Acreage Production Yield
per farm Bushels per acre
North Carolina 90.000
South Carolina 80,000
Louisiana _______ 62,000
Tennessee _ 80.000
Total South 849,000
New Jersey 24,000
Other States 80.000
Total TT. S 953,000
The yield per acre for this crop falls slightly below the average for tlie
past ten years, 93 1-3 bushels. The crop sold at an average of $1.10 per bushel,
so that its value per acre Avas nearly .$101 .00. A noticeable feature in tlie
table is tliat in tlie six heaviest producing states (first six in order) but litth'
over one-tlii)-d of an acre on the average is devoted to this crop. The average
yields art- also low when comjjarcd to ciops of from 200 to 400 Ijushels per acre,
which ai'c I'cadilv obtained bv careful ji'rowers.
SWEET POTATOES AND YAMS
Test Made 1).\ Lind-^as ( rawley, I'l'in. Appomattox Ajiiicultural llijili S(li<»ol.
This test on sweet potatoes was made by Lindsay Crawley, Principal Appomattox
Agricultural High School, on sandy loam low in fertility. The previous crop of oats
yielded onlv 20 bushels per acre. The check plot received no fertilizer, and yielded
30 bushels;" the PK plot received 44U pounds acid phosphate and IGn pounds muriate
of potash per acre, and the yield was 5 5 bushels; the NPK plot received in addition
150 pounds Sulphate of Ammonia, and yielded KMt bushels, a gain of 45 bushels,
worth ii!24.!Mt aliove the cost of the Sulphate of Ammonia.
Test Made by IMeree Odor, .ApiMniiattox, \ a.
Test with sweet potatoes made by Pierce Odor, .\ppomattox. Va. The addition of
Sulphate of .Ammonia at the rate of l.'iii pounds per acre increased the yield from 210
bushels to 2G0 bushels, a gain of 50 bushels, which sold for $28.25 over and above the
cost of the Sulphate of Ammonia.
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