152 



etable matter, very materially increases the water-hold- 

 ing capacity of our soil. The more humus we have in 

 the soil, the greater is the number of particles, conse- 

 quently the greater amount of surface to hold water. 

 It also aids in the movement of moisture through the 

 soil, and in the encouragement and development of root 

 growth. 



. The existence of the humus in the soil we know to 

 be absolutely necessary to successful growing of crops. 

 It is where this humus abounds that we find the great- 

 est development of nitrates in the soil, not alone because 

 nitrates are carried into the soil with the fertilizer as a 

 part of it, but because of the chemical action which takes 

 place in the soil. A good deal is said about the carrying 

 of nitrates into the soil, and in certain crops gathering 

 the nitrogen from the air and storing it in the soil, but 

 the fact is that the greater portion of the nitrates in the 

 soil are prepared there by the chemical action which is 

 always stimulated by barnyard manures. 



PERMANENT EFFECTS. 



There is one great advantage in the practical use of 

 barnyard manures in the semi-arid belt. The effect is 

 more lasting when the manure is properly applied 

 than in the soils of the more humid regions. In these 

 latter regions the greater rainfall lias a tendency to wash 

 out the humus below. This trouble of washing out is 

 especially perceptible in the gravelly soils of New York 

 and the New England states. There is another advan- 

 tage of the semi-arid belt which will be appreciated when 

 these facts are better understood by the masses, for our 

 observations so far clearly show that manures are even 

 more valuable here than in the east, not that our soil is 

 not fertile, but the more humus we have in the soil the 



