1 ee 628° phtegn . a Toe’ afl LAWES AGRICULTURAL TRUST ioe Rothamsted Experimental, Station e0\. 7 Harpenden 99 Guide to the Experimental Plots 1906 PRICE - ONE SHILLING NET LONDON | JOHN MURRAY, ALBEMARLE STREET, W. 1906 | y yy i! va Lene f Bh ( (i fi * ( vi re) LAWES AGRICULTURAL TRUST Rothamsted Experimental Station Harpenden Guide to the Experimental Plots 1906 PRICE - - ONE SHILLING NET LONDON JOHN MURRAY, ALBEMARLE STREET, W. 1906 INTRODUCTION COMMITTEE OF MANAGEMENT Sir J. EVANS, K.C.B., F.R.S. (Chairman). H. MULLER, LL.D., F.R.S. (Treasurer). H. E. ARMSTRONG, LL.D., F.R.S. fH. BROWN, LL.D., ERS. W. CARRUTHERS, F.R.S. Sir M. FOSTER, K.C.B., D.C.L., F.R.S. Sir C. LAWES-WITTEWRONGE, Bart. Sir J. H. THOROLD, Barr. J. A. VOELCKER, M.A., Ph.D. DIRECTOR A. D. HALL, M.A. CONTENTS GENERAL PLAN oF THE EXPERIMENTAL FIELDS Tue RotTHaMstTeD SoiL AGpDELL Firetp—Crops grown in Rotation Barn Fretp>—Mangel Wurzel METEOROLOGICAL OBSERVATIONS Tue Park—Grass Land mown for Hay every year BroapDBALK Firetp—Wheat Hoos Fietp—Barley 3) Leguminous Plots . Potato Plots—Residue of Manures Inoculation of Leguminous Plants Wheat after Fallow LittLe Hoos Fietp—Residual Value of Manures PAGE INTRODUCTION Mr (afterwards Sir) Jonn Benner Lawes was the founder of the Roth- amsted 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 of Rothamsted in 1834. In 1843 more systematic field experiments were begun, and the services of Dr (afterwards Sir) J. H. Gilbert were obtained as Director, thus starting the long association which only terminated with the death of Sir John Lawes in 1900, followed by that of Sir Henry Gilbert in 1901. The Rothamsted Experimental Station has never been connected with any external organisation, but has been maintained entirely at the cost of Sir John Lawes. In 1889 he constituted a trust for the continuance of the investigations, setting apart for that purpose 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 provisions 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. The field experiments, which began in 1843, have on some of the plots ‘een 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. ‘he 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 should be remembered that the object of the Rothamsted experi- ments is to ascertain “how the plant grows,” and only indirectly to find the most paying method and manuring; hence both the nature and the quantities of material applied are not to be taken as indicating the aHAnITES to be used in practice. SNYGTV OGNO? -mMatA Toy syqPaljoog SPOT] [equauLTeax gy Pore bt ER SAIILG THE ROTHAMSTED SOIL The Rothamsted soil was described by Lawes in 1847, as follows :— “'The soil upon which my experiments were tried consists of rather a heavy loam resting upon chalk, capable of producing good wheat when well manured ; not sufficiently heavy for beans, but too heavy for good turnips or barley. The average produce of wheat in the neighbourhood is said to be less than 22 bushels per acre, wheat being grown once in five years. The rent varies from 20s. to 26s. per acre, tithe free.” It is fairly uniform in the different fields, and consists essentially of a heavy loam containing little coarse sand or grit, but a considerable amount of fine sand and silt, and a large body of clay. In consequence, the soil has to be worked with care, becoming very sticky and drying to im- practicable clods if moved when wet. It “runs together” if heavy rain falls after a tilth has been established, and then dries with a hard, unkindly surface, these difficulties being much exaggerated on the plots which have been farmed for a long time without any supply of organic matter in the manures. The most notable feature in the Rothamsted soil is the amount of calcium carbonate in the surface layer; analyses of the earliest samples available (1856) show more than 5 per cent. in the surface soil of Broad- balk field. The subsoil below the depth of 9 inches contains little or no calcium carbonate, and this fact, together with the varying proportion in the surface soil, indicate that the original soil was almost devoid of calcium carbonate, and that the quantity now found in the surface soil has all been applied artificially. AGDELL FIELD Crops grown in Rotation ps § The Agdell field, which was put under experiment in the year 1848, differs from the other Rothamsted fields in that it is farmed on a four-course rotation of Swedes, barley, clover (or beans) or fallow, and wheat, instead of growing one crop continuously. It is divided into three main plots, one of which (O) has received no manure, the second (M) mineral manures only, and the third (C) a complete manure, containing the same minerals, but also nitrogen in the form of rape cake and ammonium-salts. The manures are applied to the Swedes only, the other three crops of each course being grown without manure. Each of the three plots is further subdivided :— Half the plots carry clover or beans as the third crop of the course, and half the plots are bare fallow. This shows the effect of introducing the leguminous crop into the rotation, as compared with the bare fallow. On this field the long-continued cropping without manure on O affects the successive crops in the rotation very differently. The Swede crop is least capable of growing in the impoverished soil, and is reduced to less than a ton per acre; the clover and barley crops are also small, but the deep-rooted wheat crop is comparatively little affected, and yielded as much as 19°6 bushels per acre in 1903, the fifty-sixth year without any A.—Plan of the Plots in Agdell Field on which Experiments have been made on Four-Course Rotation. 1848 and onwards. C. Complete Manure for Root Crop. As ‘*M” and 200 lb. Ammonium-salts, and 2000 Ib. Rape Cake per acre. PEGT 2 PEOT 21 M. Minerals only for Root Crops. 500 lb. Superphosphate, , 2 500 lb. Sulphate of Potash. PLOT 4j)/PLOT 3 100 lb. Sulphate of Soda, 200 lb. Sulphate of Magnesia, per acre. Unmanured. | ee Or nw Si Pe : . | PLOT 5 | t | | | ee eg Clover Falicw pee Total area of ploughed land, about 3 acres. Area of each of the 6 divisions, 2 acre. The 2 lower divisions, Unmanured continuously (Plots 5 and 6). The 2 middle divisions, Mineral Manure, for the Roots, each Course (Plots 3 and 4). The 2 upper divisions, Mineral and Nitrogenous Manure, for the Roots, each Course (Plots 1 and 2). The 3 left-hand divisions, Clover (or Beans), 3rd year each Course. The 3 right-hand divisions, Fallow, 3rd year each Course. The double lines indicate division paths between plot and plot. CROPS IN ROTATION if manure. With minerals, but without nitrogen, the Swedes continue to give a fair crop; the barley and wheat are ‘but: little better than on the unmanured plot, while the clover grows almost as freely as on the com- pletely manured plot. TaBie |.—Hfect of Manure on Crops grown in rotation, Agdell Field. Average produce per acre over the five last Courses, 1884-1903. oO. M. C. Unmanured, arenes Manne: Roots (Swedes) . , ; . Cwt. 15°9 2082 399°9 Barley Grain ; : : . Bush. 15°8 20°0 27°7 Barley Straw : : : . Cwt. 11°3 12°7 18°5 Clover Hay * : : F . Cwt. 9°4 35°5 37°8 Bean Corn} . : : : . Bush. 15°9 28°3 19°6 Bean Straw + 3 : : > Cwt. 8°8 17:0 ats Wheat Grain j : ; . Bush. 26°2 36°1 37°71 Wheat Straw 5 ; ‘ S'Cwk 20°8 sla 33°0 * Average of 3 courses. +t Average of 2 courses. TaBLe Il.—Cvops grown in rotation, Agdell Field. Produce per acre over the last complete Course (14th), 1900-1903. | O. M. Be ieee Maren omplete Minera Unmanured. and Nitrogenous i Manure. anaes. 8 Year. Crop. 5. 6. 3. 4, ule 2. Beans Beans Beans Fallow. or Fallow. or Fallow. or Clover. Clover. Clover. 1900 Roots (Swedes) a Gwits 44°8 15°8 201°6 BPA 480°6 480°0 1901 /| Barley Grain . . Bush. | 16°3 22°1 £59 22°3 25°1 29°4 \| Barley Straw. . Cwt. | 13°8 9°3 12°9 158 nies 1902 | Clover Hay . 2 (Owe as 0-1 ee 3°7 ia 671 1903/| Wheat Grain . waash;:,), 20°23 18°9 21°9 28°9 23°6 27°9 °\| Wheat Straw 5 wt. 17°9 16:2 24°9 32°4 28°4 32°2 When the plots 2 and 4 grow a good crop of clover, the residues of the crop have a very beneficial effect upon the succeeding crops of the rotation, as compared with the crops of plots 1 and 3, which are bare fallowed; the wheat is increased by something like 15 per cent., the roots (although manured) are slightly better, and the barley, following the roots, still shows the value of the preceding clover crop. No such residue seems to be left behind by the bean crop, whenever that is taken in the rotation instead of clover. On the unmanured plot 6, only, the clover shows no effect on succeeding crops, because there its growth is too small to leave behind any residue of nitrogen. 8 AGDELL FIELD Unmanured. Minerals only, Complete Manure no Nitrogen. Fic. 1.—Effect of Manure upon Crops grown in Rotation. Total Produce. Averages of Five Courses (1884-1903). Swedes in 100 ecwt.; Barley and Wheat in 1000 Ib. ; and Clover in 10 cwt. Taste II].—Crops grown in rotation, Agdell eld. Exfect of the largest Clover or Bean Crop on the following Wheat Crop. Total produce per acre. Wheat, 1895. Wheat, 1863. Clover, ; Beans, tees 1894. ‘After After Difference 1862. After After Difference Fallow. | Clover due to Fallow. | Beans due to i ~*1 Clover. 7) Coes Beans. Cwt. Lb. Lb. | Per cent. Lb. Lb. Lb. | Percent. O. Unmanured 5 16°5 3131 | 3193 | +-2°0 3603 7222 5281 | --26°9 M. Mineral Manure. | 59°7 4220 | 5180 | +22°7 4033 7910 6090 | -- 23:0 C. Complete Manure | 76°7 | 4547 | 5209 | +14°6 | 5755 8792 7674 | -—12°7 Taste 1V.—Crops grown in rotation, Agdell Field. Effect of Clover or Beans on the following Wheat Crops. Total produce per acre. Wheat.t Wheat.§ Clover a Bean Crops.* | after | After | Differencei Crops.t After After | Difference ; vey.| due to ; : due to Fallow. | Clover. Clover. Fallow. Beans. Beane: Cwt. Lb. Lb. | Per cent. Lb. Lb. Lb. Per cent. O. Unmanured -| 15:2. | 4173 | 3475 | —16°7 | 1888 4907 4373 | —10°9 M. Mineral Manure.| 44°4 5245 | 5613 | + 7:0 2615 5528 | 5447 S115) C. Complete Manure | 52°9 | 5479 | 6180 | +11°9 | 3177 6092 5929 | — 2°7 * 5 years (1874, 1882, 1886, 1894, and 1902). + 8 years (1854, 1858, 1862, 1866, 1870, 1878, 1890, and 1898). t 5 years (1875, 1883, 1887, 1895, and 1903). § 8 years (1855, £859, 1863, 1867, 1871, 1879, 1891, and 1899). CROPS IN ROTATION 9 = : : : ; ; The diagram, Fig. 2, shows in a graphic form the benefit the whole rotation receives from the growth of clover, even when the root crop recelves nitrogenous manures. \\ Z_\ | i\ After Clover. After Fallow. Fic. 2.—Comparative Effect of Clover or Bare Fallow on the succeeding Crops in the Rotation. Total Produce—In 1000 lb. for Clover, Wheat, and Barley, and in 100 ewt. for Roots. BARN FIELD Mangel Wurzel ‘The experiments upon mangels began in 1876, but the land had been receiving similar manures for other root crops since 1856. The field is divided longitudinally into eight strips running the whole length of the field ; each of these strips receives one manure throughout its length ; farmyard manure alone on Strip 1, and in combination with super- phosphate and sulphate of potash on Strip 2, nothing on Strip 8, super- phosphate alone on Strip 5, superphosphate and sulphate of potash on Strip 6, and complete minerals, including sulphate of magnesia and B.—Plan of the Plots in Barn Field on which Experiments have been made with Root Crops. 1843 and onwards. "PT satay ‘OF sawag ‘O) sarwag "VW satay Valley. Mangels, unmanured. ‘CO saiwag Total area of ploughed land, about 8 acres. je 2, 5, 6, 7, and 8, of each Series, rather over } acre. 3, of each Series, about =. acre. Area of Plots 4, of each Series, about + acre. 9, rather over ;4; acre. The double lines indicate division paths between plot and plot. common salt, on Strip +. ‘The strips are then subdivided into plots by cross-dressings of nitrogenous manures; nothing on the O Series, nitrate of soda on Series N, ammonium-salts on Series A, rape cake on Series C, and a combination of ammonium-salts and rape cake on Series AC. MANGELS TaBLeE V.—E£xperiments on Mangel Wurzel, Barn Field, beginning 1876. Quantities of Manures per acre per annum. Strip Manures g i = pc s Bip ee | @ | £2 | 88 |3a- ms g as ae | 852 ES = ae ae Zng ss | & 2 ea |/55° & >) RS De. = ) 5 Rn RS = Tons | Cwt Lb. Lb. Lb. 1 14 Hind Ba0 2 14 3°5 500+ we sie 4 3°5 500 200 200 5 3°5 Hon 6 3°5 500 ae Te 3°D 200 200 8 S56 Nitrogenous Manures running across all the Strips. SeriesO.| N. A. AC. C. Se a S* 2 es | ea | 8S | Ba | as 2 |#2 | #3 | as | eg | de ° ie 3 <4 <4 Lb. Lb. Lb. Lb. Lb. Lb. 550 400 | 2000 400 | 2000 550 400 | 2000 400 | 2000 550 400 | 2000 400 | 2000 550 400 | 2000 400 | 2000 550 400 | 2000 400 | 2000 550 400 | 2000 400 | 2000 550 400 | 2000 400 | 2000 TaBLE VI.—Sarn [eld Mangel Wurzel. * Equal parts Sulphate and Muriate Ammonia of Commerce. + The addition of Potash to Plot 2 began in 1895. Season 1905. + Commenced in 1903 only. Produce of Roots and Leaves per acre. Cross-Dressings. ©: N. A. AC. C. Strip. Strip Manures. Rape Cake x Nitrate Ammonium- and Rape DE of Soda. salts. Ammonium- Cake salts. ae | Tons. Tons. Tons. Tons. Tons | Han ly f, R. 21°04) 83°52 24°80 25°93 24°12 ae ie tfOp | "aca 5°50 5:91 5°61 : (| R. 21°88] 88°75 80°27 31°59 29°54 2 | Dung, Super., Potash \lL. 4:06 5°76 6-68 7-36 5°83 | [ R. 82s {« one \ 17°56 31°62 23°86 4 | Complete Minerals =| f 4-421) Rye : | L. 107 |\* 5-43 |p 3°80 7-08 3°88 5 | Superphosphate only ROE) ae Se a8 ee oe aise! 4°27 3°54 3°96 3°80 fi R. 8:07] 20°42 18°02 25°47 £091 Beg seP rs OS Soh e064. SSE 3°82 7-23 3°76 7 | Super.,Sulph. Mag.,and/| R. 38°47) 22°69 19°48 28°58 22°45 Chloride Sodium ell] 10; ee: 4°65 3°96 7°60 4°41 8 N fi R. 2°68 9°5 5°29 8°60 8°02 one . ° . 2 it 1°21 4°55 3°89 4°36 3°52 * Received an equivalent amount of Phosphoric Acid, Nitrogen, and Potash, but without any Soda Salts. 12 BARN FIELD The value of farmyard manure in growing mangels is evident, especially when they are grown continuously on the same land. In favourable seasons it is possible to obtain good crops by the aid of manures contain- ing no organic matter, as seen in 1905; but in ordinary years the bad texture of the soil which results, and its tendency to lose water on account of the lack of humus, affect both the germination of the seed and the growth of the plant in its early stages. Taste VII.— Barn eld Mange Wurzel. Average produce of Roots per acre over 27 years (1876 to 1902). Cross-Dressings. O. N. A. AC, C. Strip. Strip Manures. | : Rape Cake NpuO.. || | Senda: a1) oe Rien | aries salts. Tons. Tons. Tons. Tons. Tons. 1 Dung only . - : 17°44 24°74 Nis 24°05 23°96 2 | Dung, Super., Potash* . |..17:95 25°19 22°35 24°91 24°43 4 | Complete Minerals : 5°36 18°01 14°86 25°49 21°33 5 | Superphosphate only . 5-21 15°40 7°66 10°38 11°13 6 | Super. and Potash 5 |) a 15°38 14°03 22°48 18°63 8 None . : ° 5 3°91 10°24 5°89 9°84 10°00 * The addition of Potash to Plot 2 only began in 1895. Effect of Nitrogen To ascertain the effects of nitrogen, it is best to examine Strip 4, which receives a complete mineral manure with different compounds of nitrogen. Series A, which receive ammonium-salts, should also be compared with Series N, receiving nitrate of soda. The general superiority of nitrate of soda as a nitrogenous manure for mangels is most strikingly seen on Plots 5, where potash is omitted. : The diagram, Fig. 3, shows on the left hand the average results ob- tained with the varying amounts and compounds of nitrogen on the Plots 4 in question, where there is an abundant supply of mineral manure. The right-hand half of the diagram shows the effect of the same nitrogenous manures when used in conjunction with dung instead of complete minerals. The injurious effects of the very large amounts of nitrogen added to some of the plots is very manifest wherever there is more nitrogen than the plant can properly deal with. The leaves have a dark green appearance, are much curled and crinkled, and show an increased tendency to variega- tion, the chlorophyll collecting into dark green or almost black blotches on the lighter background of the leaf. he leaf stalks are often much more coloured, and become a bright orange yellow. On these plots the leaves do not ripen off and obtain the general yellow flaccid appearance presented on the more healthy plots when the crop is ready to lift; instead, the outer leaves begin to die and shrivel up quite early in October; in some places they show numbers of dead spots and burnt-looking patches round the edges of the leaf. MANGELS i Thus, towards the end of October, the plots receiving the excess of nitrogen present a very unhealthy appearance; a large proportion of the plants seem scorched and withered as regards the outer leaves, and only show a cluster of small dark green active leaves at the heart. WITH COMPLETE MINERALS. WITH DUNG. (Plots 4). (Plots 1). Tons per Acre Ac 25 » Series ie) A N C AC O A N C AC Fic. 3.—Mangel Wurzel. Effect of increasing amounis of Nitrogen. Average Produce of Roots per acre, 1876-1902. O = No Nitrogenous Manure. N = 86 lb. Nitrogen as Nitrate of Soda. A = 86 lb. Nitrogen as Ammonium-salts. C = 98 lb. Nitrogen as Rape Cake. AC = 98 lb. Nitrogen as Rape Cake, and 86 Ib. Nitrogen as Ammonium-salts. Effect of Mineral Manures The effect of the different mineral constituents of a manure upon the mangel crop can be seen by an examination of Plots 4, 5, and 6. The great increase of crop comes as a rule when potash is added to the superphosphate, and is to be correlated with the fact that the mangel is essentially a sugar-producing plant, and that large supplies of potash seem to be essential to the processes in the plant which result in the formation of sugar and similar carbohydrates. The effect of potash and of the other saline manures is plainly visible in the appearance of the plants themselves. On the plots receiving potash the plant begins to ripen early, the leaves turn yellow and become flaccid, so that in October these plots may be seen outlined from the rest by their lighter tint. 14 BARN FIELD Tons perAcre 25 ——-___--—-—. -—— 290 15 10 — 5 Series With With With With With No Nitrogenous Nitrate Ammonium Rape-cake. Rape-cake & Manure. of Soda. alts. Ammonium Salts. No Minerals. ZSuperphosphate. Superphosphate Superphosphate, Potash, Ys and Potash. Magnesia. and Soda. Fis. 4.—Manzel Wurzel. Effect of various Mineral Manures. Average Produce of Roots per acre, 1876-1902. Uffect of Artificial Manures with Dung A comparison of Strip 2 with Strip 1 shows the effect of adding superphosphate and sulphate of potash to the dung and_ nitrogenous manures applied to Strip 1. || 17082 L125 8 0:073 244°1 |] 61°3 | 41°5 June . -| 3°893 | 4°054 15 1°382 169°1 | 66:2 | 50°7 July . -| 1°402 1°473 10 0°310 264°8 | 73°4 | 55:0 August -| 3°342 3°459 20 0°919 180°1 | 67°0 | 50°3 September .| 2°143 2-248 12 0°739 129°2 1) 65 e479 October .| 1°583 1°665 16 0°320 ISS: |) SASS ies November .| 3°127 3°231 20 2°753 60°0 | 46°6 | 53°6 December .| 1:057 | 1-103 13 0:990 30°4 3°9 | 34°5 Total orMean! 25:507 | 26-436 | 179 11581 1579°9 | 55°4 | 41-2 THE PARK 1% THE PARK Grass Land Mown for Hay every Year The experiments upon grass at Rothamsted began in 1856, about 7 acres of the park close to the house being set aside for the purpose. The land has been in grass as long as any recorded history of it exists, for some centuries at least. It is not known that seed has ever been sown, and at the beginning of the experiments the herbage on all the plots was apparently uniform. The plots, of which there are twenty in all, vary somewhat in size, which lies between one-half and one-eighth of an acre. Up to 1874 in- clusive the grass was only cut once, the aftermath being fed off by sheep. Since that time there has been no grazing, and the plots are generally cut twice in the year. The grass is made into hay in the usual way, and the whole produce of each plot is then weighed. TaBLE X.—WManuring of the Permanent Grass Plots per acre per annum, 1856 and since. Nitrog s = itrogenous Mineral Manures. Manures. Abbreviated Descriptio oa S t eee || Plot. of Manures. ae iP ees eget £2 \e4 a” 145 '@2 | 32 | Za | as 4 | a 2 | 3 | Lb. | Lb. | Cwt | Lb | Lb. | Lb. | Lb, or } Unmanured every year 2 | Unmanured; following Dung first 8 years. ... eh GARE Dos Meee): hea [nae 1 | Ammonium-salts alone; with Dung also first 8 years . Z ‘ 3 , . | 200 4-1 | Superphosphate of Lime. : Siillze-te|| seem nner ss 8 | Mineral Manure without Potash . ; cos | wet PO | oa | ao0 oe 7 | Complete Mineral Manure . , 31 3°5 | 500] 100] 100 6 | As Plot 7; Ammonium-salts alone first 13 | Mere ea ar eh cell goal eR [SBOG P100'| 100) 15 | As Plot 7; Nitrate Soda alone first 18 years| ... | ... | 3°5 | 500} 100} 100) 5 | Ammonium-salts alone (to 1897) . 4 .| 400] ... 17 | Nitrate of Soda alone . Z : : 5H (eee || PAE | 4-2. Superphosphate and Ammonium-salts | A001 oo 10 | Mineral Manure (without Potash) and Am- monium-salts . 400| ... | 3° *250 |) 100 9 pai «a Mineral Manure and Ammonium- alts - | 400 3°5 | 500) 100; 100 13 | As Plot 9, and Chaffed Wheat Straw also. | to 1897 . A | 400} ... | 3°5 | 500} 100} 100 11-1} Complete Mineral Manure and Ammonium- salts - - -| 600] ... | 3°5 | 500) 100); 100 11-2) As Plot 11-1, and Silicate of Soda - - | 600] ... | 3°5 | 500) 100| 200) 400 16 | Complete Mineral Manure and Nitrate Soda 275 | 3°5 | 500} 100} 100 ; 14 | Complete Mineral Manure and Nitrate Soda 550] 3°5 | 500) 100) 100/ ... * Reduced in 1905 to 100 lb, C.—Plan of the Plots in the Park on which Experiments have been made‘on the Mixed Herbage of Permanent Grass Land. 1856 and onwards. Total area under Experiment, about 7 acres. 1, 2, 3, 4-1, 4-2, 5-1, 5-2, 11-1, 11-2, and 12, each + acre. 6, 7, 8, 9, 10, 13, and 18, each 3 acre. tie 15, 16, and 17, each 3 acre. 19 and 20, each 4 acre. Area of Plots | GRASS FOR HAY 19 TABLE XI.—Produce of Hay per acre. Average over the period of 47 years (1856-1902), the 10 years (1893-1902), and the individual year 1905. Rothamsted. Total of first, and second crops (if any). Averages over Plot. Abbreviated Description a a OTT of Manures. 47 years 10 years 1905. (1856-1902). | (1893-1902). Cwt. Cwt. Cwt. 3 21°9 15°9 19°4 12 } Unmanured every year { 24°5 18°5 94°7 2 | Unmanured; following Farmyard Dung for first 8years . 27°-9* 17°4 23°2 1 | Ammonium-salts alone (= 43 Ib. N. ); with Farm- yard Dung for first 8 years. a : 4 35 °4t 24°9 26°3 4-1 | Superphosphate of Lime : oie Ae 23°3§ 17°8 22°3 8 | Mineral Manure without Potash . . . .| 28°1 21°6 30°3 7 | Complete Mineral Manure . : : : é 38°8 36°5 52°9 6 | Complete Mineral Manure as Plot 7; following Ammonium-salts alone first 13 years. 37°4t 36°0 46°1 15 | Complete Mineral Manure as Plot 7; following Nitrate of Soda alone first 18 years . p 37°0|| 40°8 51°9 5 | Ammonium-salts alone=86 lb. Nitrogen . «| (26°1)**| ... oe 17 | Nitrate of Soda alone=43 lb. Nitrogen. . .| 35°37 30°6 39°7 4-2 | Superphosphate and Ammonium-salts=86 lb. N. . |, 35°5§ 28°3 31°5 10 | Mineral Manure (without Potash), and Ammo- nium-salts = 86 lb. N. : 49°3 38:1 37°3 9 | Complete Mineral Manure and Ammonium-salts = 86 lb. N. 54°1 46°8 48°6 13 | As Plot 9, and Chaffed Wheat Straw also to 1897 inclusive . 62:b> = 11-1} Complete Mineral Manure, and Ammonium-salts =129 lb. N. Z ‘ ‘ 65°5 64°6 59°0 11-2| As Plot 11-1, and Silicate of Soda. . . .| 72°0 68°0 74°5 16 | Complete Mineral Manure and Nitrate Soda —42 Ib. N. 48-09 42°4 52°3 14 | Complete Mineral Manure and Nitrate ‘Soda =86 lb. N. 5 5 : 59°37 53°4 57°6 * After the change. Before the change, 42-9 cwt. § 44 years only (1859-1902). t =p Ay 49°5 cwt. pi 45 years only (1858-1902). a 33 a 30°6 cwt. ** 42 years (1856-1897). i ” 3 35°4 cwt. The Unmanured Plots Two of the plots have remained without manure during the whole of the experiment. hey are situated near the extremities of the field, and show a slight but constant difference in crop. Taking the average of the whole period, these unmanured plots have produced rather more than a ton of hay per acre per annum. If we compare the successive ten-year returns, there is no sign of approaching exhaustion or great falling-off in crop from year to year. The impoverishment of these unmanured plots i is more to be seen in the character of the herbage than in the gross weight of produce. Weeds of all descriptions occupy the land, and the relative proportion they bear to the grasses and clovers has increased from year to 20 year. the herbage. THE PARK } A fair proportion of clovers, both red and white, is found on these plots, but the weeds, which amount to 26 per cent. taking the average over the whole period, have of late years constituted nearly one-half of The most prominent species among the grasses are the TaBLE XII.—Percentages of Gramineous, Leguminous, and Miscellaneous Herbage. Average of 47 years (1856-1902, and 1902 separately). Rothamsted. Furst crops. Plot. Averages over 47 years (1856-1902). Season 1902. Manures. > Gram- Legu- Miscel- ine. minose. | lanex. Per cent. | Per cent. | Per cent. } Unmanured every year |G eae eee 258 | 64:9 9°0 | 261 Unmanured; following Farm- yard Dung for first 8 years. | 75°5 4°3 20°2 Ammonium-salts alone( = 43 lb. N.); with Farmyard Dung for first 8 years . : 5) fiefs: 0°7 ilitos Superphosphate of Lime 68°0 5°8 262 Mineral Manure without Pot- asbir.c : 2 E 70°6 6°8 22°6 Complete Mineral Manure 62°0 23°8 14:2 Complete Mineral Manure as | Plot 7; following Ammo- nium-salts alone first 13 yrs. Complete Mineral Manure as Plot 7; following Nitrate of Soda alone first 18 years Ammoniunm-salts alone = 86 lb. N. - : - : .| 80°5 O24) 19 al! Nitrateof Sodaalone=431b.N.| 71:0 Dede | tot | Superphosphate and Ammo- nium-salts =86 Ib. N. . .| 882 os el Pais Uf Mineral Manure (without Pot- ash),* and Ammonium-salts | =S86 Ib. N. = : : 907 0-1 9°2 Complete Mineral Manureand Ammonium-salts=86 Ib. N. | 88°7 0-4 10°9 As Plot 9, and Chaffed Wheat Straw also to 1897 inclusive | 92°83 0°3 7°4 Complete Mineral Manureand Ammonium-salts=129Ib. N. | 95° 0-1 2! As 11-1, and Silicate of Soda. | 97°5 0 2°5 Complete Mineral Manure and Nitrate Soda =43 lb. N. 82°9 54 ul hey Complete Mineral Manure and Nitrate Soda = 86 lb. N. 90°6 1°3 81 | Gram- inex. Per cent. 34°3 38°1 24°4 77°6 54°4 28°8 20°3 18°4 26°2 Legu- minose. Miscel- lanee. Per cent. | Per cent. 7°5 16°1 5°7 * Including Potash first 6 years. 58°2 45°8 10°7 Quaking Grass, so generally taken as a sign of poor land, which con- stituted 20 per cent. of the whole herbage in 1903, and Sheep’s Fescue ; among leguminous plants the Bird’s Foot Trefoil ; and Burnet, Hawkbit, and Black Knapweed among the weeds. GRASS FOR HAY 21 Use of Nitrogenous Manures alone Three of the plots—17, 5,and 1—show the effect of the long-continued use of nitrogenous without any mineral manures, Plot 5 has been receiving 86 lbs. of nitrogen as ammonium-salts, Plot 17 half the quantity of nitrogen in the shape of nitrate of soda, and Plot 1 the same half quantity of nitrogen as ammonium-salts, though on this plot dung was applied in each of the first eight years of the experiment. It is very evident when a nitrogenous manure is used alone for grass, nitrate of soda is far more effective than the ammonium-salts; e.g., on Plot 17 it has given an average crop of 35 ewt. against 26 cwt. produced by double the quantity of nitrogen in ammonium-salts on Plot 5. ; Mineral Manures used alone On three of the plots no nitrogenous manures have been applied since the beginning of the experiments. On Plot 7 a complete mineral manure, Without Nitrogen. With Nitrogen. ——— PR AMNS es b : | 8 i 4-2 10 9 Fic. 6.—Effect of the various Ash constituents with and without Nitrogen on the produce of Hay per acre. Average over 47 years (1856-1902). Cwt. per Acre 50 +0 30 20 Plots 3 &I2 4-| Plots 3 and 12. Unmanured. | Plot 4-2. Super. and Amm.-salts = 86 lb. N. Plot 4-1. Superphosphate. Plot 10. Minerals (without Potash) an Plot 8. Minerals with Potash. Amm.-salts = 86 Ib. N. = Plot 7. Complete Mineral Manure. | Plot 9. ropes Minessl. Manwee and mm.-salts = 86 lb. N. ® 22 THE PARK supplying phosphoric acid, potash, magnesia, and soda, is used ; Plot 8 has received the same application, but without potash, since 1861, while Plot 4-1 receives superphosphate only. With the complete minerals a fair crop is grown, averaging over 14 ton of hay for the first cut alone. The reason that the crop on this plot is maintained, although no nitrogen is supplied in the manure, lies in the free growth of leguminous plants. It will be seen that, taking the average over the whole period, the leguminous plants form 24 per cent. of the herbage, and the proportion has increased from year to year. The omission of potash on Plot 8 has caused a very striking difference both in the crop and in the character of the herbage. ‘The average crop has been about one-quarter less over the whole period, and shows a pro- gressive decline in fertility, until at the present time it is little more than half that of Plot 7. The poor results on this plot, as compared with Plot 7, must be put down to its poverty in leguminous herbage, the development of which seems to depend on a free supply of potash. Of late years the proportion of leguminous plants on this plot has amounted to about one-half of that found on Plot 7, the grasses are about the same, the difference being made up by an increased amount of weed. Plot 4-1, which each year has received superphosphate only, now pre- sents a very impoverished appearance, and is giving no more crop than the unmanured plots. Indeed, the aspect of this plot, where the most abundant grass is Quaking Grass, and where weeds, chiefly Hawkbit, Burnet, and Plantain, are unusually prominent, would seem to indicate that the land is more exhausted here than on the unmanured plot. Complete Manures—Nitrogen and Minerals Among the plots which receive both nitrogenous and mineral manures, Plot 9, with a complete mineral manure and ammonium-salts should be compared with Plot 14, which is exactly similar except that the nitrogen is applied in the form of nitrate of soda, and again with Plot 16, where only half the amount of nitrogen is applied, but again as nitrate of soda. The nitrate of soda gives the heavier yield, the herbage is also more diversified, and there is not the total absence of leguminous plants which marks the plots receiving ammonium-salts. Two characteristic plants, Soft Brome Grass and Beaked Parsley, are found only on the plots receiving nitrate of soda, the corresponding umbelliferous plant where ammonium-salts are used being the Earth Nut (Conopodium). On Plot 11 the same mineral manures are applied with an extra amount of ammonium-salts, so that the nitrogenous manuring is excessive. As a result the vegetation consists entirely of tufts of three coarse grasses— Meadow Foxtail, Yorkshire Fog, and Tall Oat Grass. The soil has also become sour and unhealthy, with the result that the plant is dying in patches, except on the upper portion of the plot where lime has been applied, and on the half numbered 11-2 where the silicate of soda is used. The effect of omitting potash from the complete manure is seen on Plot 10, and again on Plot 4-2, where superphosphate and ammonium- salts only are applied. It is noticeable that the grass on these plots is weak in the straw and liable to fungoid attacks. GRASS FOR HAY 23 Cwt.perAcre 60 50 40 3.0 20 Plots 3612 7 9 I 16 14 Fic. 7.—Effect of Nitrogenous Manures on the produce of Hay per acre. Average over 47 years (1856-1902). Plot 3 and 12, Unmanured. Plot 7. Complete Mineral Manure, no Nitrogen. Plot 9. Do. and Amm.-salts = 86 lb. N. Plot 11. Do. do. =129 Ib. N. Plot 16. Do. and Nitrate of Soda=:43 lb. N. Plot 14. Do. do. = 86 lb. N. Changes in the Herbage following changes in Manuring Plot 6 was up to 1868 manured with ammonium-salts alone, like the adjoining Plot 5: the ammonium-salts were then replaced by a complete 24 BROADBALK FIELD mineral manure containing potash. The result is seen in the way leguminous plants have gradually invaded the plot until they now predominate as they do on Plot 7, where mineral manures have been used throughout. ‘The southern half of Plot 5 has also been manured with minerals instead of ammonium-salts since 1898, and the gradual invasion of leguminous plants may now be seen in progress. The northern half of Plot 5 has been unmanured since 1898, when the ammonium-salts were discontinued. On Plot 15 nitrate of soda was applied up to 1875, when a change to a complete mineral manure was made, with the same result of the incoming of the leguminous plants. The southern halves of Plots 1 to 4-2, 7 to 11-2, 13 and 16 were dressed with ground quick-lime at the rate of 2000 lb. per acre in January 1903, and changes in the herbage resulting therefrom are now in progress. Plot 18, which, up to 1905, was in an impoverished condition, has since been receiving a complete manure except for the omission of any phosphoric acid. Use of Dung Three plots were selected in 1905 to illustrate the effects of dung applied occasionally, either alone or in combination with artificial manures, as follows :— Plot 19. 14 tons Dung 1905, and every fourth year. Unmanured intervening years. Plot 20. 14 tons Dung 1905, and every fourth year. 13 ewt. Nitrate of Soda 200 Ib. Superphosphate 100 lb. Sulphate of Potash | Every intervening year. Plot 13. 14 tons Dung 1905, and every fourth year. 6 ewt. Fish Guano 1907, and every fourth year. BROADBALK FIELD—WHEAT The experiments on the continuous growth of wheat were begun in the Broadbalk field in 1843, but for the first eight years the manuring was of a varied description, so that only three of the plots have received the same treatment during the whole period of sixty years. The plots as seen to-day began in 1852, since which time the few changes in manuring have been matters of detail and not of principle. The chief difficulty experienced in growing wheat continuously is that of keeping the land clean; not only does the crop occupy the ground for the greater part of the year, and so leave little opportunity for cleaning operations, but the weeds whose habit of growth is favoured by the crop tend to accumulate from year to year. ‘hus in spite of repeated hand- hoeings, some weeds, like the “ Black Bent” grass, Alopecurus agrestis, are kept under with the greatest difficulty. D.—Plan of the Plots in Broadbalk Field, on which Wheat has been grown sence 1843-4, i l, | Is 42 D ‘ ' ‘ ! Hote eat ela ; ; f Brick Trench for collecting the Pipe Drainage from each Plot. Total area of ploughed land about 11 acres. Area of Plots 3-4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, and 19, each } acre. Area of Lands A and B of Plot 2, each 5; acre. Area of Plot 20, about + acre. The double lines indicate division paths between plot and plot; also a path across the centre of each plot. 26 BROADBALK FIELD TaBLe XIII.—2Lxperiments on Wheat, Broadbalk Field. Manuring of the Plots per acre per annum, 1852 and since. Nitrogenous Manures. Mineral Manures. Abbreviated Descripti os o |e | Sil nouou|no Oa Beste 5 of a artine ie a& loo Ej £2 | 24 £4|8% Fa| o |#3| 8a] Se| 42/43 | 28 as ror ra : isl oY ay =n as Fu ce A | 17°83 | 18°] | 14:4.) 14:3 2.N/ Superphosphate and Nitrate of Soda . | 44:0 | 35°9 | 32°9 | 26°2 | 23:0 | 25:8 3N)| Alkali Salts and do. Pe oleomie2octelelcon Li Losaltaes 4.N/} Complete Minerals and do. 43°5 | 34°9 | 32°2 | 27°4 | 22°6 | 24:7 1C} Rape Cake alone . : : 5 SOP aol sOn 29-0 22:45 VSeaa hy 7 2C | Superphosphate and Rape Cake . AV“5) Widae2y |e 28"D | 25°9 | 196 | 17 °7 3C}| Alkali Salts and do. . 5 |) BHI || ZAI! || PADESIE| eek | aLSeal |) AOS} 4C| Complete Minerals and do. AiO) | 32°5 |) 84:2) || 24°5) 920-1 | 23-1 7-1 | Unmanured (after dung 20 yrs., 1852-71) | 27°0*| 19°9 | 14°1 | 15°4*| 12°8 | 8-6 7-2 | Farmyard Manure : : : = |) 476 | 42°6 | 39°4 | 291, |) 28°38 | 27°9 * Average 31 years (1872-1902). Effect of Nitrogenous Manures The effect of nitrogenous manures upon the barley crop is best seen by comparing the yields of the various Plots 4, all of which receive the same mineral manures ; the diagram, Fig. 11, shows this comparison in a graphic form. Effect of Mineral Manures The diagram, Fig 12, shows in a graphic form the effects of the various mineral manures, the nitrogen supply being the same in all cases. The great importance of phosphoric acid to the barley crop is seen on comparing Plots 3 and 4, which only differ from one another in the omission of phosphoric acid on Plot 3. In the tield the most striking effect is seen in the hastened maturity brought about by the phosphoric acid. By comparing Plot 2 with Plot 4 we can see the effect of omitting potash from the manure. Where nitrate of soda is used as the source of nitrogen the soda liberates sufficient potash from the soil to supply the needs of the crop, but with ammonium-salts the omission of potash has latterly begun to tell upon the yield, though it did not do so in the earlier years of the experiment. : C 34 HOOS FIELD Total Produce per Acre. 6000 |b. $000 ISS SSA Plot 10 40. 4A. 4N. 4:Ce 7-2 Unmanured Minerals Minerals Minerals Minerals Farmyard only. +43 Ib.N. +43 1b.N. +49 |b. N. Manure asAmmonia. as Nitrate. as Rape Cake. Grain per Acre, |b. eee Straw per Acre, |b Fie. 11.—Yield in Barley (Grain and Straw) with different sources of Nitrogen. Averages for 51 years (1852-1902). The figures in the labels indicate bushels of Grain and cwt. of Straw. BARLEY 35 Total Produce er Acre. oe 5000 Nitrogen Nitrogen Nitrogen Nitrogen, and and only. PhosphoricAcid Phosphoric Potash. and Acid. Potash. S Ee | WS Grain per Acre, |b. Straw per Acre, |b. Fic. 12.—Kffect of Mineral Manures on the yield of Barley (Grain and Straw). Mean of Series A. N. and C. 51 years (1852-1902). The figures in the labels indicate bushels of Grain and cwt. of Straw, Season 1906. F.—Hoos Field Leguminous Plots. ‘9O06/ UMOSAI ‘$OG/ AEW UI UMOS JAAO/D A¥IS/Y ‘O06! UMOSAU ‘HO6) ACW Ul UMOS JIAO/D PIY POG] ABW UI UMOS aUIIINT 906! jiudy umosat %Ob6I /28G907IO Ul UMOS SIYI72AA HOG] MO//E4 ‘906! P? G06l SAY4II9/ DO6/ MO//©4 [Total area under experiment about 3 acres. ] G.—Plan of the Plots in Hoos Field, on“which Potatoes were grown without Manure, and with various Manures. 26 years, 1876-1901. In 1902 and 1903 Barley, and in 1904 Oats, were sown, without manure, to determine the duration of the residues of the previous manuring. In 1905 Barley was again sown on Plots 1-4 without manure. Plots 5-10 sown with Leguminous seeds. Total area of ploughed land about 2;'; acres. Area of each plot } acre. The double lines indicate division paths between plot and plot. eZ HOOS FIELD LEGUMINOUS PLOTS 1848-9 onwarpDs ‘The small plots (see Plan on page 36) represent portions of the original plots on which attempts have been made to grow leguminous plants continuously since 1848. Various combinations of mineral manures have been used up till 1898, but after the first few years very small crops have been grown, and the clovers in particular generally fail. After fallowing in 1903 to clean the plots, they were resown as before in 1904. The remainder of the area was formerly occupied by similar small plots of the same leguminous plants. These were ploughed up in 1898, and five crops of wheat were taken without manure in order to test the amount of nitrogen accumulated by the leguminous crop and left in the soil. In 1904 black tartarian oats were sown, and in the oats, lucerne, red clover, and alsike clover were sown on three strips; a fourth strip, fallowed in 1904, was sown with vetches in October of that year, as shown in the Plan on page 36. ‘The new plots run across the old ones at right angles. The following table shows the crop obtained in 1905, after which the clover and vetch plots were broken up and resown in a barley crop in 1906. TaBLE XVII.—Produce per acre, as Hay. Season 1905. Gap ec Rone |- eae | Cwt. Cwt. Cwt. Lucerne . Diheeby 16°6 | 38°1 Red Clover 2537, | 21°5 | 47°2 | Alsike Clover . 36°9 | 36°9 | Vetches . 45°8 45°8 | HOOS FIELD—POTATO PLOTS Restpve oF Manvres On ten plots potatoes were grown with various manures for 26 years (1876-1901), with the results set out in Table XVIII. In 1902 the manuring was discontinued and barley sown; this was again followed by barley in 1903, and by oats in 1904. The yield produced by the residues of the manures applied to the potatoes is shown in Table XVIII. 38 HOOS FIELD “BISOUDB]L PUB BpoOg ‘[svyod Jo soyeyding pur ‘oyeydsoydaodng « OANUBIL [RIOWI POXIW 5, » omuryy | , amuepyy | ISTT 9.06 188 8-31 OL9T 8-6 6-3 / ; : : * ATWO aMURIY [RAIOUTT, poxT, FOLT 1.66 068 &-8T II8T 1.98 1G 2 Amo teraydeondiodrie Gg9T 9.68 SPLT 69% 6Z9P 0-49 og d : ; ; ; : : : : [eroul, PeXTAL Puv ‘uosoryIN “Q] 98=~epog ayvAqIN J §69T 6-08 VE9T 6-86 98GP b-F9 6-9 ; ; ; . ; ; = c - [ROUT POXIPA, puv ‘ussorIN “q] 98 = S}[es-tniuoTAUTY f S961 1-86 T16 9-81 GLGd 6-69 | LZ - : ; : : uasOI}IN “q] 98 = BPOg 2}eA}IN, OLIT L4G SLOT 3-61 PLLS L-6¢ 4 oa " UISOTIN “] 98 =S}[es-uNTUOWULy 896E G19 98PE 6-0F cIIS ¥-6L I-& : : : * osje uasoajIN “q] 98= "pos come | Ajsnotaoad pue [gst ul pur ‘‘soydaadng Ajsnoroa pue ZEgT ‘douls puv ggg] ‘suo, FL ‘omuBp pavcuaeg | 0908 @.g¢ FLEE 6-96 91%S 0-1 8-4 ot tone ofeydsoquednige A[SNOIAdIg ‘aOUIS pue EgeT ‘suoy FT ‘ounue yA, pavAurreyy f 9LIT G1 0ZOL BGT 3181 p-98 8-6 Nike Pat ye. pk SUPPL Sa ha preAuey A[snoracig ‘souls pue ZggT ‘poanuewu oJ OPEL I-84 DPS 9-6 66LT 6:&& tL ¥ ; 3 : : * 90UIS pue 9/87 ‘painueuU ‘qT “ysng ‘a1 “YySng ‘aT “ysug "Smo, “MBIYS “UIRIy "MRIYS “UIRLD “MERIYS “ULBID “aro” tod 1®40., pessoerqy 1®40, poessoay 1e40., passer SIOqU, (-ayevydsoydaedng jo proqsur qynoySnoryy 1vjOf, Jo POST SBM STS OISVE “QT OOF LOGT 04 LEST ‘Sava g 9q9 uy) = aa a 19°2 14°7 + 4°5 WO 55 (1856-65) : D 26°1 15°9 +10°2 LOM s5 (1866-75) . : - 13°5 11°9 + 1°6 ORs (1876-85) é : ‘. 14°8 11°3 + 3°5 10, (1886-95) 3 - ; 15°1 121 + 3:0 LOW; (1896-1905) . 5 14°3 | 17 + °2°6 50) ag (1856-1905) 5 3 16°7 125 + 4:2 Last year (1905) . : : 12°9 18°0 = 5:1 AveracEs—Produce after Fallow, reckoned at the yield per Acre of the whole area, half in Crop and half Fallow. 5 years (1851-55) 9°6 14°7 | - 51 10 ,, (1856-65) 13°0 15°9 | — 2°9 10 ,, (1866-75) 6°8 11°9 | = yal 10% (1876-85) © 74 11°3 — 3:9 ira) StLS8G-06) 7°5 12°1 | - 456 10 9 (1896-1905) (2 ilalsy/ = 4°5 50 ,, (1856-1905) 8°4 12°5 —- 4°1 Last year (1905) 6°4 18°0 | —11°6 bie “Ee OO's” FLED Resipuat VatuE oF Manures The object of the experiments in this field is to test the residual value of certain typical manures, z.c., the value of the residues left in the soil after one or more crops have been grown since the time of their applica- tion. 'To eliminate the effect of season, the result yielded by the residue is in all cases compared with that of a new application of the same manure, as well as with a continuously unmanured check plot. The ordinary dung is made by feeding beasts with hay and roots only, the beasts making the cake-fed dung alongside receive also an ordinary allowance of linseed and cotton cake. The two lots of dung are then laid up in heaps for a short time, and weighed out immediately before applying. The yields obtained so far are not given as trustworthy; conclusions can only be drawn when the average over a long period can be taken. H.—Ittle Hoos Field. Plan of Rotation Plots arranged to test the Residual Value of various Manures—one, two, three, and four years after their application. Crops selected—Swedes (1904), Barley (1905), Mangels (1906), and Oats (1907). Third Year, 1906—Mangels. 4 3 Dung Dung 9 g (Cake-fed), (Cake-fed), 16 tons per acre, [ IG tons per acre, in 1906. 05 N in 1904. Shoday, ! ton per acre, /ton peracre, | / ton per acre, in 1906. in l905 in 1904. 2 / Guano, Guano, 8 cwl. peracre,|8cwt.peracre,| 8 cwt peracre, in 1906. inlg9o05. in 1904. 3 2 Rape-cake, /0 cwt.peracre, Ee Sulphate of Potash tn 1906 Each plot received 8 cwt. Swperphosphate per acre in 1904, and 8 cwt. of Adjoins Hoos Field 7 3 | Superphosphate, 600 |b peracre. | 600/b. peracre, in 1905. 4 Bone Meal, 430 /6. per acre, In 1906. 2 cwt. in 1906, with 8 cwt. of Sulphate of Potash. Basic Slag, Basic Slag Basic Slag, 600 Ib. per acre} 600/b. peracre, | 600 1b per acre, Each plot received 1 ewt. of Sulphate- Ammonta per acre in 1904 and 1905, and in 1906. in 1905. in 1904 Adjoins Broadbalk Field. Area of each plot 4th acre. Series A deals with the residual effects of Ordinary Dung. ” B 9 ” ” Cake-fed Dung. s9 G 9 39 3 Shoddy. 33 D ” ” rr Guano. » > 9 “- Rape-cake. » F 3% 13 99 Superphosphate. hi] G 33 °° os Bone-Meal. H ” Basic Slag. In each series the manure is applied to one plot in 1904, to another plot in 1905, to a third plot in 1906, and to a fourth plot in 1907. All the plots in the Series A to E, which deal with Nitrogenous Manures, receive, as necessary, equal amounts of Phosphates and Potash. Similarly, all the plots in the Series F, G, H, dealing with Phosphatic Manures, receive equal dressings of Nitrogenous or Potassic Manures as required. \ Horie ay Benes A to E no Nitrogen throughout, Series F PRINTED BY OLIVER AND BOYD EDINBURGH For a General Account of the whole of the Experimental Work at Rothamsted, see The Book of the Rothamsted Experiments By A. D. HALL, Director PUBLISHED BY JOHN MURRAY, Lonnon, 1905 10/6 net