1907.] 



PUBLIC DOCUMENT — No. 33. 



45 



Average Yields per Acre (Potinds). 



It will be noticed that the haj crop on the combination of 

 manure and potash is less than on the larger quantity of 

 manure alone in both cases, the average difference being at 

 the rate of G-i6 pounds jier acre. The rowen crops are more 

 nearly equal, the average difference amounting to only 118 

 pounds per acre in favor of the larger application of manure. 

 The heavier application of manure means, of course, a larger 

 application of nitrogen. It is not surprising, therefore, that 

 the first crop, which includes a considerable proportion of 

 timothy and redtop, is heavier where the manure is most 

 largely used. The rowen crop is made up in much larger 

 proportion of clover, and the proportion of clover is greater 

 where the lesser quantity of manure and the potash salt are 

 applied. Estimating the manure to cost on the land $5 per 

 cord and the high-grade sulfate of potash at the market 

 rates, the usual annual difference in cost of materials ap- 

 plied has amounted to about $6 to $6.50 per acre, the lesser 

 amount of manure and potash costing about that amount less 

 than the larger application of manure. 



This experiment has now continued sixteen years. Dur- 

 ing this time ten corn crops have been raised. The average 

 yields per plot and the averages for the two systems of 

 manuring are shown in the following tables : — 



Average Yields per Acre. 



