TIME OF PLOWING SMALL-GBAIN" STUBBLE. 13 



ing and spring plowing were nearly equal. At harvest there was a 

 small amount of moisture in plat A to a depth of 6 feet, while that 

 in plat B had been exhausted. 



The remainder of the moisture in plat A was used by weeds, and 

 at the time plat B was plowed, September 18, 1912, the moisture in 

 both plats was equal. In the spring of 1913 the first determination 

 showed there had been a slight increase in the water content of plat 

 A to a depth of 3 feet, while there had been an increase in only the 

 first foot of plat B. The water in plat B was so nearly exhausted 

 by the first week in June that the crop was burned beyond recovery, 

 while plat A had water enough, supplemented with a light precipita- 

 tion, to produce 4.8 bushels of wheat. The yields from all plats were 

 very low, but the average yield was higher for all three crops on 

 spring plowing. 



The fight precipitation of August and September, 1913, did not put 

 the soil in condition for plowing until October 14. There was very 

 little weed growth in the fall and the sampling of October 2 shows 

 very little stored water. The water content of plat A in the spring 

 was twice as great as that of plat B, but neither had an appreciable 

 amount of available water below the second foot. While there was 

 but a small difference in the moisture content of the two plats, the 

 yield of grain from plat B was only 55 per cent of that from plat A. 

 The yield of straw was the same from each. The slight difference in 

 water content in favor of plat A, with the smaller number of weeds 

 in the grain and a normal precipitation during the growing season, 

 had enabled it to produce a good crop of grain, while plat B had 

 dried up before maturing. 



SUMMARY. 



The average yields from spring and from fall plowing show that 

 the blind following of a rule prescribing any particular time of plow- 

 ing might cause a reduction as often as it does an increase in the 

 yields of the three spring crops of wheat, oats, and corn. The very 

 small difference in yield each year from plats plowed at the same 

 time, when compared with the greater difference from plats plowed 

 at different times, indicates that the time of plowing is one of the 

 most important of the controllable factors in crop production. 



The great variation in the time and amount of precipitation is the 

 important climatic characteristic of this region in eastern Colorado 

 that must be kept constantly in mind when considering the time of 

 plowing. No dependence can be placed on a heavy precipitation in 

 August and September, yel ii frequently occurs. When there is such 

 precipitation, measures should he taken to conserve it. Weeds being 

 the important factor in its dissipation, cultivation to destroy them 

 should be given us soon as possible after Hie occurrence of rains in 



