EROSION AND PLANT GROWTH 



187 



ments of the field peas, native bromegrass. and cultivated wheat 

 grown in the two soils. 



Pounds of Water Required by Peas, Bromegrass, and Wheat per 

 Pound of Dry Matter Produced 



Summary of Plant Growth and Water Requirements of Peas, Brome- 

 grass, and Wheat 



" The length of stem of the peas is given instead of the length of leaf. 



The first table shows that a much greater amount of water 

 was required on the eroded than on the noneroded soil for the 

 production of a unit of dry matter of each of the three plants 

 tested. This fact is particularly significant, inasmuch as the 

 eroded soil can retain only a comparatively small amount of 

 water for the growth of vegetation. 



Figure 61 was prepared from the data given in the second table 

 and summarizes the vegetative growth and water requirements 



