ORGANIC MATTER FOR CORN LAND 



133 



are on newer land, where as large increases are not yet to 



be expected as on old cultivated land. 



Again, the Ohio station ' has shown that the value of 



manure may be increased by adding and composting a 



small amount of mineral fertilizer with it. The following 



table summarizes the data, showing a marked increase 



in the value of the manure where treated with mineral 



fertilizer. 



TABLE XXV 



Value op Barnyard Manure treated with 40 Pounds per 

 Ton op Different Minerals. Applied to Crops in 

 A Three-tear Rotation op Corn, Wheat, and Hay at 

 the Rate op 8 Tons per Acre. Average for Fourteen 

 Years 



In this case, the mineral was mixed with the manure as it 

 was removed from the barns. A part was applied directly 

 to the land in each case, and a part allowed to decay in the 

 yards for about three months. The former method 

 seemed to be the better. 



SUMMARY 



96. In the foregoing discussion on the theory of applying 

 fertilizers and manures for raising cereals, it appears that 

 the permanent maintenance of the soil in a productive 



1 OUo Agr. Exp. Sta., Circ, 1^0 : 112. 1912. 



