PEAS FOR DRY-FARMING 249 
Alfalfa is a leguminous crop and gathers nitrogen 
from the air. It is therefore a good fertilizer. The 
question of soil fertility will become more important 
with the passing of the years, and the value of lucern 
as a land improver will then be more evident than it 
is to-day. 
Other leguminous crops 
The group of leguminous or pod-bearing crops is of 
great importance; first, because it is rich in nitroge- 
nous substances which are valuable animal foods, and, 
secondly, because it has the power of gathering ni- 
trogen from the air, which can be used for maintain- 
ing the fertility of the soil. Dry-farming will not be 
a wholly safe practice of agriculture until suitable 
leguminous crops are found and made part of the 
crop system. It is notable that over the whole of the 
dry-farm territory of this and other countries wild 
leguminous plants flourish. That is, nitrogen-gather- 
ing plants are at work on the deserts. The farmer 
upsets this natural order of things by cropping the 
land with wheat and wheat only, so long as the land 
will produce profitably. The leguminous plants 
native to dry-farm areas have not as yet been sub- 
jected to extensive economic study, and in truth very 
little is known concerning leguminous plants adapted 
to dry-farming. 
In California, Colorado, and other dry-farm states 
the field pea has been grown with great profit. In- 
