186 



Experiments on continuous grooving of grain at Woburn, 

 England, J. A. Voelcker ('Jour. Roij. A<il. Sor. <>/ Etif/land.S scr.,;^,}^^- 

 ■ lUx^—'JOaj. — These experiments were eoiiinieiiced in 1877, and were 

 designed to show the effects of varions arriticial niannres and barnyard 

 manure upon grain crops grown year after year on the same land. The 

 results are here reported for the j^ears 1880 and 1800, the thirteenth 

 and fourteenth years of the exijerimeuts. The plats were one fourth 

 acre each, and the same fertilizers have, exeei)t in a few easivs, lu-en used 

 each year since 1877 on the respective plats. 



Continuous growth of irhcKt. — The variety of wheat grown was IJro- 

 wick Ked, of which ]»('cks ]M'r acre were dilihlcd in l)y liand in the 

 fall of each year. Tlie fertilizers applied i)er acre consisted of anuno- 

 nium salts (sulphate and chloride in equal parts) and nitrate of soda, 

 each in amounts ecjuivalent to ."»0 pounds of ammonia ]ier acre, used 

 singly; a mixture of L*(K) i)ounds of potassium suli)hate, 100 pounds 

 of sodium sulphate, 100 pounds of magnesium sulphate aiul 3."»(» 

 pounds of superplu)sphate of lime, which was used alone and to which 

 was added, in separate cases, anunoninn) salts (Miuivalent respectively 

 to 50 and 100 i)ounds of ammonia, and nitrat«' of soda eipiivalent 

 to 50 and 100 pounds of ammonia; rape cake, 800 and l,r>00 pounds 

 respectively, furnishing nitrogen equivalent tr) 100 and IMM) i»ounds of 

 anunonia; and l)arnyard manure estimated to contain nitrogen eiiuiv- 

 alent to -00 pounds of ammonia. Two jtlats have rep<'ived no fertilizer 

 whatever since 1877, and one plat has receivi'd (udy tlie mineral ferti- 

 lizers (potassium, sodium, and magnesium sulphates, and sup(M'plios- 

 phate of lime). The mineral manures wer*' applied Just before seeding, 

 the top-dressings of ammonia salts and nil rat*' of soda in the spring 

 (Ai)ril), the barnyard manure early in February, and the rape cake in 

 the latter part of .January. 



Tlie yields of the duplicate iinm.inured plats ajjroe very closely in 1889; in 1890 

 plat 7 is rather higher. Minerals alone, without nitrosjen. have as usual tjiveu no 

 increase. In 1889 ammonia salts, whether used alone or with mineral manures, ]»ro- 

 duced a larger crop than nitrate of soda, hut in the drier year, 1890, the exact 

 reverse was the case, nitrate of soda in each instance then showing the higher 

 return. The appearance of the jilats on which these nitrogenous to])-dressings are 

 used is in the earlier stages very poor, and the plant is very uneven; nevertheless, 

 toward harvest they seem to ]>ull up wonderfully, and the yield is much more than 

 it has seemed likely to he. The small increase (J hush els) from ]iuttiiig on in 1S?<9 

 the d<»uhle dressing of nitrate of soda is very noticealile, and while the omission of 

 amnuniia salts for a single year reduces the grain to 21 bushels, the ettect of leaving 

 out nitratt; of soda is to take it as low as 11.4 hushels, which is even below the 

 unmanured yield. This greater diminution in the case of nitrate of soda is also very 

 marked in 1890. The effect of rape cake, applied so .is to give 100 pounds of 

 anunonia per acre, is greater than that of farmyard manure estimated to contain 

 double that amount. Plat 11a [unmanured, having been manured last in 1882 with 

 baruyaril manure] still seems to show the presence of some unexhausted fertility 

 from the farmyard m.anure put on in former years. 



Continuous growth of harlcjf. — The fertilizers used in this experiment 

 were the same in kind and amount as those iu the experiment with 



