14 Weeds. 



escape of nitrates more effectively than a 

 crop of weeds, owing to its greater uni- 

 formity. Whenever weeds grow spontane- 

 ously in sufficient numbers to be of much 

 service in either of the ways named above, 

 they are sure to give trouble to whatever 

 useful crop is grown upon the same land, 

 much more than will offset any advan- 

 tage to be gained from them. 



In good farming weeds should not be 

 tolerated at all, because ( i ) they rob the 

 useful, cultivated plants of their due share 

 of plant food and moisture; (2) they also 

 injure them by crowding and shading; 



(3) they harbor insects and plant diseases; 



(4) they add greatly to the labor of clean- 

 ing grain for market and for seed ; ( 5 ) they 

 frequently interfere with a regular rotation ; 

 and (6) they are usually not of much value 

 as food. To all these things may be added 

 the statement that the longer they are left 

 to grow unchecked, the greater is the work 

 required to completely subdue them. 



/. Weeds rob useful plants of their due 

 share of plant food and moisture. Weeds 

 feed upon precisely the same kinds of food 

 as the useful plants among which thev 

 grow, and they draw heavily upon the avail- 



