16 



might be supposed, winter crops fare better with this procedure than 

 spring crops. By plowing in fresh manure several months before 

 seeding, a much better result is obtained, because the nitrates are on 

 hand and are being formed at the growing period of the crops. 

 Experience has abundantly proven that it is better to plow manure 

 into the soil and allow it to lie there rather than in the pile. Whether 

 it is better to leave manure spread upon the surface of the 

 land rather than to plow it in or leave it in the pile, depends chiefly 

 on the amount of loss caused by surface drainage. This may be 

 small, but if the ground is frozen, the surface inclined, and the man- 

 ure half-rotted or more, the loss will be considerable. The nitrate 

 destroying bacteria are of several species and have thus far been 

 found in straw and various other litter, in soils, and in the dung of 

 herbivorous animals. They have not been found in human excre- 

 ment or that of the carnivora or birds. 



When barnyard manures are made with bedding devoid of much 

 decomposable organic matter, the nitrate-destroj'ing bacteria cannot 

 work in them, for they cannot obtain the soluble organic food neces- 

 sary for their subsistence. Anything like sand, loam or turf, there- 

 fore, may be used for bedding without incurring the disadvantage 

 due to litter. 



Wherever much nitrate of soda is applied to crops, there is pro- 

 duced a relatively large yield of straw, which, in turn, leads to a 

 large use of this material as litter. This excessive quantity of straw 

 in the manure materially lessens its value in the manner described. 



CONCLUSIONS : 



Of the three common conditions of barnyard manure, half-rotted 

 manure is the most valuable, and well-rotted manure the least, 

 because of their relative amounts of nitrates. 



Manure should be kept i)acked away from the air as tightly as 

 possible, and if netted should be plowed under just before planting, 

 otherwise several months before that time. 



The more litter used in the manure, the greater liability to loss of 

 nitrogen. 



The use of bedding material free from decomposable organic mat- 

 ter is a means of protection against loss of nitrogen. 



