66 PRACTICAL CORN CULTURE 



wheat one year and clover one year. As we have said be- 

 fore, the straw should be returned to the land if the beans are 

 hulled. The clover is often worth more for pasture than it 

 would be if allowed to rot down as a humus and fertilizer. 

 If the clover seed is hulled the straw should of course be 

 returned to the land. If the clover fields are not needed 

 for pasture it is a good plan to cut the first crop early and let 

 it lay to enrich the land. This early cutting of the first crop 

 will often double the yield of seed in the second crop. 



HUMUS 



Humus may be defined as decaying vegetable matter. It 

 varies in composition and quantity in different soils. The 

 productive capacity of land is measured largely by its phys- 

 ical conditions and the physical condition depends largely 

 upon the amount of humus and nitrogen in the soil. When 

 old land is packed and breaks up cloddy it is often due to the 

 fact that the humus has been exhausted. While the grain 

 crops are dependent on several elements it is usually the 

 supply of nitrogen which limits the crop production. All 

 the nitrogen used in the growing of corn crops is taken from 

 the humus in the soil, while the legumes get a certain amount 

 from the air. 



Since the grain crops are dependent on humus, it can 

 readily be seen that every effort should be made to restore 

 as much humus to the soil as is taken out by the crops and 

 the rapid decay which results from open culture. Vegetable 

 or animal trash of any kind will make humus, although some 

 kinds, like clover hay, and stable manure will make a great 

 deal more than will straw, corn stalks or leaves. 



The drouth-resisting qualities of a soil depend largely 

 upon the amount of humus in it. 



