286 



BOARD OF AGRICULTURE. [Pub. Doc. 



July is the best guarantee the farmer can have against 

 weeds. A field not sown down will, as is too often the case, 

 be covered with Roman wormwood, pigweed, and other 

 undesirable growths. The plowing in of green crops should 

 be practised on all land subject to cultivation whenever 

 there is a possibility of so doing. With corn, a crop of red 



Horse Bean. Red Clover. 



Fig. 1. Nodules on the roots of legumes. 



clover, mustard or melilotus (sweet clover) can be sown 

 after the last cultivation, and this can be cut and utilized 

 for feeding, and the roots plowed under just before the next 

 year's planting. The common red clover and sweet clover 

 possess an advantage over mustard, as their roots are pro- 

 vided with nitrogen-containing nodules, the product of 

 bacterial activity (see Fig. 1). In this case a certain 

 amount of nitro<ren is added to the soil, whereas with such 



