PLOWING UNDER VS. DISKING IN MANUEE 219 



tive material to mix with manxire; but the results have not been 

 sufficient to encourage its use.^ 



Lime of any kind should not be mixed with manure when it 

 is being stored, because it favors fermentation. It also liberates 

 the ammonia. 



Good Practice to Mix Horse and Cow Manures. — ^Horse 

 manure is a warm, dry manure, and cow manure, cold and wet. 

 The mixing of these two manures in a manure shed is advantageous, 

 since the one will absorb the liquid of the other, and the resulting 

 mixture is much more easily handled. 



Light Applications Better Than Heavy. — It has been clearly 

 shown that, in general farming, it is better to use medium to light 

 applications of manure rather than heavy. In a thirty-five year 

 test made at the Pennsylvania Station, a twenty-ton application 

 per acre in a four-year rotation resulted in crop increases valued 

 at only $5.38 per acie more than when twelve tons were applied. 

 The applications were made twice in the rotation or at intervals 

 of two years, at the rate of ten and six tons per acre, respectively. 

 Corn, oats, wheat and mixed clover and timothy were the 

 crops grown. 



Similar results were secured at the Ohio Station in a seventeen- 

 year test in which eight-ton and sixteen-ton applications, made once 

 in five years, were compared; and at the Indiana Experiment 

 Station, where comparisons were made between 14.2-ton and 8-8- 

 ton applications, extending through twenty-three years. These 

 results show that when the supply of manure is limited, it is better 

 to cover as much land as possible at the rate of six to eight tons 

 per acre than to get over comparatively few acres with a heavy 

 application (Fig. 148). Herein lies the great value of the manure 

 spreader (Fig. 146). It is also well worth remembering that 

 frequent light applications prove more profitable than heavy 

 applications at long intervals. 



Plowing Under vs. Disking in Manure. — The plowing under 

 of manure is usually recommended, especially on the heavier soils, 

 largely because of the loosening effect produced in addition to 

 its fertihzing value. It is best to plow under coarse fitter (in the 



9 In a 15-year test made at the Ohio Station m which forty pounds of 

 gypsum were mixed with each ton of manure used, the average results showed 

 a gam, above the cost of the gypsum, of eighteen cents m case of yard manure, 

 and a loss of five cents per ton when it was mixed with stall manure. The 

 gypsum cost six dollars per ton. 



