Nature-Study Agriculture 



A partner- 

 ship that 

 is mutually 

 helpful 



How the 

 farmer may 

 help nature 



W. T. Skilling 



FIG. 29. Nodules on the roots of a peanut plant. Each nodule is the home 

 of a colony of nitrogen-fixing bacteria. 



longing to the legume family, he will find upon the 

 roots little swellings, or " nodules," about as big as 

 pinheads (Figs. 29 and 30). It is in the nodules that 

 colonies of the nitrifying bacteria live, and these can 

 be seen with the aid of a powerful microscope. The 

 bacteria draw much of their own nourishment from the 

 plant but do it no harm, and they give to the plant the 

 nitrogen that it could not get alone. (Exp. 3.) Nitro- 

 gen thus taken from the air is added to the ground when 

 the plant decays. 



Now comes the farmer's part in this process. If 

 he plants vetches, clover, field peas, or some such legUv 

 minous crop, and plows it under, he may expect the sue 



