118 HATCH EXPERIMENT STATION. [Jan. 



The crops, as in previous years, are of substantially equal 

 value, the manure alone giving 1.1 bushels more grain than 

 manure and potash, while the latter gave 160 pounds more 

 stover. The combination, 4 cords of manure and 160 pounds 

 sulfate of potash j)er acre, will cost about $6.40 less than 6 

 cords of manure alone. We have now grown eight corn 

 crops on this field, and the average yields are at the rate 

 per acre for the two manurings : — 



Average of Eight Crops. 



The money cost of the materials applied to the plots re- 

 ceiving manure and potash for the ten years during which 

 the experiment has continued is at the rate of about $81 less 

 than on the other plots. The manure alone, however, has 

 produced yields exceeding the combination of a smaller 

 amount of manure and potash, at rates per acre amounting 

 to shelled corn 34.4 bushels and stover 2,600 pounds. 

 During two years since the experiment l>egan the field has 

 been in grass, and the yields on manure alone exceed those 

 on manure and potash at rates per acre amounting to hay 

 2,244 pounds and rowen 1,170 pounds. Such an amount 

 of corn and hay at average prevailing market prices would 

 have been worth about $44.18. In using the large amount 

 of manure alone, then, one would, in effect, allowing the 

 manure to cost $5 to the cord on the land, have expended 

 about $81 for products worth but little more than one-half 

 that sum. 



This field has now been seeded to mixed grass and clover 

 seeds. The stand on all plots is good, but the clover is 

 proportionally more abundant on the plots receiving the 

 manure and potash. 



It is believed that these experiments conclusively indicate 

 that corn may be more cheaply grown on a combination of 

 manure and potash than on manure alone. 



