Effect on Succeeding Crops 263 



available nitrogen compounds undoubtedly retard the 

 proper ripening of the fruit. 



In the case of cereal crops, a green-manure may lead 

 to the same result as that caused by a very heavy ap- 

 plication of animal manure or of nitrate. The grain 

 crop may develop the dark green color so characteristic 

 of plants generously fed with nitrogen, and may finally 

 lodge and prove a partial or total loss to the farmer. 

 Again, in the case of crops like the sweet-potato, the 

 growers are careful not to plant it immediately after 

 the soil has been enriched by a heavy growth of some 

 leguminous green-manure. There is always danger under 

 such conditions that the forcing effect of the readily 

 available green-manure nitrogen may result in the 

 production of sweet-potato vines at the expense of the 

 roots. 



It may be safely stated that the successful utili- 

 zation of green-manures must always reckon with the 

 bacterial activities that concern their decomposition. 

 A proper understanding of the principles involved will 

 help the farmer to secure larger yields of superior quality. 

 Ignorance and indifference will lead to inferior products, 

 and, not infrequently, to smaller yields. 



