2^^ Illinois State Dairymen's Association. 



of wheat except the plowing just after the harvesting of one crop 

 and just before the sowing of the next. 



The crop of wheat harvested from plots 1, 2, 13, and 13 

 (which were not preceded by a crop of cowpeas) gave an aver- 

 age yield of 10.72 bushels of wheat per acre, while plots 2, 4, 



10, and 11, that were preceded by cowpeas, produced 15.85 

 bushels of wheat per acre, an increase of a little more than 50 

 per cent induced by the cowpeas. The fertilizer applied to plot 

 9 (800 pounds) cost $11.20 delivered at Fayetteville, yet this 

 heavy application caused an increased production of only .05 of 

 a bushel more than the average increase of plots 2, 4, 10, and 



11, sown to cowpeas. Plot No. 11, fertilized Avith only the 

 stubble of cowpeas, produced .03 of a bushel more than plot 9, 

 to which was added 800 pounds of commercial fertilizer valued 

 at $11.20. 



These remarks have taken into consideration only the first 

 year's results which conform closely to those published in Bulle- 

 tin No. 62 of this Station. Plot No. 1 shows a decrease each 

 year from the first year's yields, and plot No. 12 each year 

 after the second . These two plots must be used as stand- 

 ards for comparison, by which the measure of the good effects of 

 the commercial fertilizers and of the cowpeas may be determined. 

 The slight falling off in yield in 1901 is attributed to the decided 

 deficiency in precipitation for that year, and has no bearing upon 

 the fairness of the conclusions. 



The average yield for the four years of plots (1 and 12) 

 upon which no fertilizers were used or cowpeas grown, was 

 10.05 bushels per acre. The whole cowpea plant plowed in 

 (plots 3 and 10) gave an average increased yield of 16.55 

 bushels per acre, and the stubble (plots 4 and 11) an increase of 

 10.45 bushels per acre for the four years. These increases re- 

 sulted from growing cowpeas but once, and before the first crop 

 of wheat was sown. Cowpeas planted between each crop of 

 wheat" (but not before the first) gave an increase of 17.65 

 bushels per acre for the four years against an increase of 

 only 12 bushels from 800 pounds of fertilizer applied to the first 

 crop of wheat. Two hundred pounds of nitrate of soda applied 

 to the first of four successive crops gave a gross yield of only 

 one bushel more than 100 pounds. The average yield of the two 

 nitrate of soda plots gave only 3.4 bushels more in four years 



