CHAPTER 18 



Weeds and Their Eradication 



Weeds are the farmer's most active and persistent enemy. If he would 

 keep them under control, he must wage a continual warfare against them. 

 Seldom is there soil so poor that it will not grow weeds, and the richer the 

 soil, the greater the weed crop. They seem to have been equipped by nature 

 to hold their own in the struggle for existence, for they manage to thrive 

 despite heat or cold, drought or flood. 



Some may ask: Why do weeds exist? They undoubtedly have a 

 place in nature's great plan. They are her agents in restoring fertility to 

 the soil. If unmolested they will cover the soil as a blanket, first as weeds, 

 then as brush and finally as a forest. In fact, in some parts of our country, 

 land is farmed until crops are no longer profitable, and then abandoned. 

 Weeds then take possession, and by returning nitrogen to the soil, they 

 become restorative agents. Give nature time enough and she will restore 

 any land to its normal fertility. 



Damage Done by Weeds. — It is impossible to calculate the damage 

 done yearly in the United States by weeds. Investigators roughly esti- 

 mate it to be hundred's of millions of dollars. 



Weeds Reduce Crop Yields. — Weeds are more rapid of growth and 

 more tenacious of life than cultivated plants. They crowd out the rightful 

 occupants of the soil, depriving them of air and sunshine. Being more 

 vigorous, they absorb from the soil the plant food that should be used by 

 the crops, thus reducing the yield. A ton of dried pigweed contains as 

 much phosphoric acid, twice as much nitrogen and five times as much 

 potash as a ton of ordinary manure. 



Weeds also absorb moisture in greater quantities and more rapidly 

 than crop plants. They are more drought resistant, for, having appro- 

 priated all the moisture to themselves, they continue to thrive while the 

 plant beside them dies. Experiments prove that some weeds transpire 

 250 to 270 pounds of water to develop a pound of dry matter. 



In addition to this, it is a well-established fact that weeds exert an 

 injurious effect upon crop yields by giving off from their roots substances 

 which are poisonous to crop plants. 



Weeds cause a direct money loss by reducing land values. A would-be 

 purchaser is not so apt to buy a farm where the fields are thickly covered 

 with mustard, wild carrot or the ox-eye daisy. Naturally, the loss in value 

 should be borne by the man who has allowed his land to be so abused. 



Weeds increase the expense of harvesting the crop. A field overrun 

 with weeds calls for extra labor and entails extra strain on the machinery. 

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