160 ALFALFA FARMING IN AMERICA. 



somewhat greater danger of souring land when 

 green crops are turned under than when they are 

 left to ripen and decay somewhat on the surface be- 

 fore being turned under. It is not easy to account 

 for this fact. It is always well when turning under 

 cover crops where alfalfa is to be sawn to* use a 

 larger application of lime than one otherwise would 

 use, since thus he avoids the danger of souring the 

 land. 



Cowpeas however, may do soils good and may pos- 

 sibly do them harm. It has been taught that cow- 

 peas always build soil, whether the vines are taken 

 away or left on the soil to be turned under. Prof. 

 C. A, Mooers of the Tennessee Station has shown 

 that cowpeas when cut and removed from the soil 

 have a marked effect in depleting it of fertility. 

 Probably they rob it rapidly of available phos- 

 phorus. It is plain that when cowpeas are grown 

 to prepare the land for alfa'lfa seeding they ought to 

 be turned under, not taken away from the land. 

 "Cut them and put the manure back!" Yes, but 

 would it come back? 



The Soy Bean. An easier crop to grow than the 

 cowpea is the soy bean, and it also is a soil enricher 

 and affords much humus when turned under. Soy 

 beans are of many sorts. The large growing kinds, 

 like the Mammoth Yellow, make the most vegetation 

 for turning under, while smaller growing sorts make 

 most seed in northern latitudes. Soy beans to do 

 well need soil inoculation. It will come of itself if 

 they are continuously grown on the same land. Soy 



