FIELD EXPERIMENTS WITH FERTILIZERS. 1 33 



seem to indicate that the appHcation of the hme to the soil 

 with the large quantit}^ of the sulphate was beneficial. It will 

 be noticed, however, that in all cases except one the 3uelds 

 were greater on the sections of .series A than on corresponding 

 sections of series F, which would suggest that the lime had 

 some direct beneficial effect upon the fertility of the soil, in 

 addition to its action in neutralizing acidity; for on the nitrate 

 of soda plots the residue from the nitrate in accumulating 

 would tend to cause an alkaline rather than an acid condition 

 of the soil. 



The results seem to favor the hypothesis that a soil may 

 become injuriously acid by the continued use year after year 

 of large quantities of sulphate of ammonia, and that lime may 

 be employed to correct the acidity. They also seem to indi- 

 cate that lime may often prove beneficial in other ways than in 

 the correction of acidity of the soil, especially where commer- 

 cial fertilizers have been used for a long time without stable 

 manure or organic material. 



T/ie amounts of nitrogen in the fertilizer and the proportions 

 of protein in the crop. — The results given in Tables 68 and 69 

 show the effects of the fertilizer on the yields of dry substance 

 of the crop, and on the proportions and yield of protein. They 

 are intended to show particularly the effects of the nitrogen in 

 the fertilizer on the yields of protein and its influence on the 

 feeding value of the crop. The data included in the tables are 

 the yields of crop per acre as harvested, the percentages of dry 

 matter and of protein, and the calculated yields of dry matter 

 and of protein per acre. In the last two columns of the table 

 the yields of dry matter and of protein per acre from the plots 

 where the different amounts of nitrogen were used in addition to 

 the minerals are given in percentages of the average of yields 

 from the two plots where only mineral fertilizers were used. 

 This gives an opportunity to observe the effect of nitrogen on 

 the total yields of protein. 



In discussing the results it has seemed best to omit the con- 

 sideration of plots where no fertilizers were used, as the results 

 are probably abnormal. The percentages of nitrogen in the 

 crops grown without fertilizer were in some cases greater than 

 where fertilizers were used. This seems to have been due to 



10 



