VALUE OF MANURE 11 



phosphorus and nitrogen, and there will in time result 

 a deficiency of these elements in the soil as compared 

 with potassium unless the supply of this also is reduced 

 by the selling of hay and straw, or of leafy plants, such 

 as tobacco. If mixed farming be practiced, including 

 the growing and fattening of live stock, most of the 

 potassium will be retained on the farm; but there will 

 still be a heavy loss of phosphorus in that carried away 

 in the bones of animals grown on the farm." It might 

 be added in this latter instance that the older and more 

 mature the animals fed the less will be this loss of phos- 

 phorus. This indicates that many soils under average 

 conditions require more phosphorus in proportion to 

 nitrogen and potassium than that contained in manure. 

 In other words, to make farm yard manure well bal- 

 anced, phosphorus in some form should be added to it. 

 This is done by the use of acid phosphate, steamed bone 

 meal, or finely ground phosphate rock. 



MANURE TESTS IN OHIO 



At the Ohio Station under Professor Thome's direc- 

 tion tests of farm yard manure have been running for 

 nine years, in which it was used in different rotations, 

 both alone and in combination with some carrier of 

 phosphorus and other elements. Eight tons of manure 

 per acre was the standard application. The average 

 yearly increase per acre of this one application in a 

 three-year rotation of corn, wheat, and clover was for 

 the untreated manure 14.70 bushels of corn and 744 

 pounds of stovei , a money value of $7, figuring the corn 

 at 40 cents per bushel and the stover at $3 per ton. 

 For the wheat following the corn the increase for the 

 untreated manure was 8.36 bushels of wheat and 897 

 pounds of straw, representing a money value of $7.58, 

 figuring wheat at 80 cents per bushel and straw at $2 

 per ton. For the clover following the wheat the increase 

 in yield for the manured plot was at the rate of 686 



