422 DRY LAND FARMING 



like the alfalfa crop, is too valuable for such burial. 

 There is the further objection that the price paid for the 

 seed of peas makes such feeding costly. But when peas 

 are thus buried the available nitrogen thus brought to 

 the land is very considerable and much of it has been 

 obtained from the air. 



The results from growing and burying the cow pea 

 are quite as significant as the results from growing the 

 Canadian field pea, but the domain for the cow pea is, 

 of course, in latitudes that would be too warm for grow- 

 ing the Canadian field pea at its best. The objection also 

 applies to the cow pea, that its food value is such as to 

 preclude the advisability of growing it for burial, saVe 

 in certain instances that are more or less exceptional 

 in character. 



The area in which the sand vetch will grow with 

 sufficient success to justify growing it in the dry area 

 has not been sufficiently determined as yet. If it should 

 prove true that the sand vetch may be sown with a 

 spring crop without detriment to the same, and that 

 it will grow on subsequently and furnish a large amount 

 of organic matter for burial the following season, then 

 it will follow that the mission of the sand vetch in fur- 

 nishing humus in dry areas will be one of much sig- 

 nificance, as (1) it would start in its growth without 

 detriment to other crops; (2) it would furnish humus 

 for burial without necessitating the loss of a crop, which 

 would be true of it even when buried on land that is to 

 be summer-fallowed, for such land would not in any 

 case furnish a crop that season, and (3) it would fur- 

 nish nitrogen from the air in plentiful supply. 



The place for, the growing and the burial of sweet 

 clover as for. the growing and burial of sand vetch has 

 not been well worked out, but especially under hard 

 conditions the place for the growth of this plant in order 

 to supply humus would seem to be a large one. As 



