32 THE MONTHLY BULLETIN. 



REDUCTION OF PLANT FOOD SUPPLY. 



When a farmer clears a piece of land of the brush and weeds he does 

 not expect to get a crop the first year. He plows and harrows, leaves the 

 soil open to the air and rain, turns it over in the spring and sows a 

 (;rop. Usually the third year is the best. The twigs and leaves have 

 rotted by that time, and the combined action of the elements has turned 

 them into available plant foods. Provided with this and the rapidly 

 growing supply, as the new soil is exposed to the oxidizing effect of the 

 air, the new crops yield great returns. The weeds that grew there, 

 l)efore the man cleared the land, had absorbed the plant food in the 

 surface layers, and were one of the causes of the poor crops the first 

 year. 



The following is an extract from Canadian Experiment Station, 

 Bulletin 128 : 



"Weeds naturally make use of the same foods as the cultivated plants anions; 

 which they grow. Consequently they deprive a crop of a large amoiiut of the avail- 

 able nourishment ; and they rob the succeeding crop as well. For example, au 

 analysis of the Russian thistle by Snyder shows that it contains from 12 to 17 per 

 emit as much nitrogen as there is in clover; and an ordinary thistle of this kind cov- 

 ering a square yard takes more potash and lime from the soil than two good crops 

 of wheat from the same area." 



In 1905 Minnesota produced approximately 200,000,000 ])ushels of 

 small grain. This grain was docked 1 pound per bushel l)ecause of 

 weed seeds, or 200,000,000 pounds. A. D. Wilson, of the Minnesota 

 Experiment Station, says : 



"Had the land been free of weeds the same amount of plant food, moisture, and 

 labor would have produced over three million bushels of wheat, or the equivalent in 

 other grains. This makes an annual loss due to weeds of about two and one half 

 million dollars, or an annual rental of about 30 cents per acre on every acre on which 

 small grain is grown." 



Since, therefore, all of our grain and vegetable crops, and most of 

 our tree crops, draw their nourishment from the first two feet of soil, 

 it is vitally necessary that we conserve as much as possil)le the resources 

 of our lands for our best paying crops. 



ABSORPTION OF AVAILABLE MOISTURE. 



When you consider that it requires from 225 to 1,000 pounds of water 

 to produce one pound of dry matter, you can get some idea as to the 

 importance of keeping the weeds out of the garden. In Southern Cali- 

 fornia this is especially true. Every ounce of water is needed and every 

 extra irrigation costs and lowers the net returns of the crop. It has 

 l»een estimated that it takes 7,000 pounds of water to produce one box 

 of navel oranges, and 589 pounds of water to produce one pound of 

 corn, or to make it more significant, it requires 35.3-10 pounds of water 

 to produce one bushel of corn, and 714,000 pounds of water to produce 

 one ton of oat hay. The yield of potatoes in Wisconsin in a test plot 

 was 450 bushels per acre, and this represented a water requirement of 

 1310.37 tons. 



