98 GROWING LEGUMES FOR SOIL BETTERMENT 



under in the autumn. Even corn and sorghum have been 

 used for this purpose. They produce large amounts of 

 humus when thickly planted. Sufficient time should be 

 given after plowing in such rank growth to allow the soil 

 to settle and the resulting acids to wash out of the soil 

 before planting another crop. In southern California, 

 fenugreek and Canadian field peas are used extensively 

 as winter cover crops in orchards. They are then plowed 

 under in spring as green manure. 



The quickest way to build up a worn-out soil when 

 barnyard manure is not plentiful is to give it a course 

 of treatment like that just described; then grow only 

 forage crops, buy grain to feed with them, and return 

 all the manure thus produced to the land. Dairy farm- 

 ing permits such a system to be practiced. No other type 

 of farming builds up land so rapidly. 



Another type that gives fairly quick results is to grow 

 a succession of pasture crops for hogs, keep the hogs on 

 these pastures and feed them a fourth to a half ration of 

 grain. 



There are three general methods of supplying humus 

 to the soil. The first and best is the addition of stable 

 manure. When properly managed it adds large quantities 

 of both plant food and humus. But manure is not always 

 available. When such is the case, the best thing to do 

 is to make it available. Raise more forage, keep more 

 stock, and make more manure. But this takes time and 

 capital, so that other means are sometimes necessary. 

 When stable manure is not to be had, we may plant crops 

 for the purpose of turning them under, thus adding 

 large quantities of humus at comparatively little cost. 

 Plowing under green crops is called green manuring. 

 Under certain conditions this is an excellent practice. 



A third method of adding humus is to grow crops like 

 clover and timothy. These crops are usually left down 

 for two years or more. During this time their roots 



