THE ETERNAL BATTLE WITH WEEDS 101 



of summer weather some of our choicest pasture plants give off 

 as much as twenty times their own weight in water. Many- 

 weeds are equally heavy users of water and mineral matter, 

 both so essential to the proper development of the grass crop. 

 A strong invasion of the pasture by weeds indicates misman- 

 agement of the paddock in some particular. As a rule a heavy 

 weed cover indicates a depleted soil (Fig. 28). 



Fig. 28. — INVASION OF A FARM PASTURE BY UNPALATABLE ASTERS, RELIABLE 

 INDICATOR PLANTS OF A DECLINING FORAGE YIELD. 



It is highly important to mow the pasture once, or better 

 still, two or three times during the summer, before the weeds 

 ripen their seeds. The work should be done thoroughly, with 

 the use of a mowing machine. The mowing machine should be 

 set to run moderately high, in order not to cut too much of the 

 grass feed. In some pastures this will necessitate some clean- 

 ing up and clearing, which in itself makes for better pasture. 

 Mowing prevents the weeds from spreading. It conserves the 

 moisture and mineral matter of the soil for the grass crop, and 



