406 ANNUAL REPORT OF THE Off. Doc. 



The table shows that under all the treatments the manure has 

 produced a greater effect during the second period than during the 

 first. This has been partly due to the use of lime during the second 

 period, but aside from this, there has been a steady increase in the 

 effectiveness of the manure from the earlier years of the test, such 

 season's results, as a rule, having raised the average for the entire 

 period of the experiment. 



As between the two carriers of phosphorus the superiority of the 

 acid phosphate over the floats has been greater during the second 

 period than during the first. 



It will be observed that the untreated manure has made a greater 

 relative gain than either of the phosphated manures, though still 

 far behind them. This fact, and the gain of the acid phosphate over 

 the floats, may possibly be due to an increasing demand for nitrogen 

 in the soil. In untreated manure, nitrogen is found in considerable 

 excess over phosphorus, and the treatment with acid phosphate has 

 a tendency to conserve the nitrogen. 



Acid phosphate is made by mixing sulphuric acid with the raw- 

 phosphate rock. When mixed with manure, and the heap begins to 

 heat, with evolution of ammonia, there may be a decomposition of 

 the phosphate resulting in the formation of sulphate or phosphate of 

 ammonia. 



Our experiments have shown that a ton of manure, reinforced dur- 

 ing accumulation with phosphorus, and taken directly from the 

 stable to the field, may produce increase in ordinary farm crops to 

 the value of five dollars and more, over and above the cost of its 

 treatment. It would not be fair, however, to say that the ton of 

 manure is worth five dollars, for parallel experiments have shown 

 that one dollar judiciously expended in chemical fertilizers may 

 produce an increase in the same crops to the value of two dollars, 

 and that there may be an increasing eft'ectiveness following the use 

 of such fertilizers very closely approximating that observed in the 

 use of the manure. Hence we conclude that the value which should 

 be placed upon manure in comparison with fertilizers, should be 

 about two dollars and a half per ton, which would be approximately 

 the value of fresh cattle manure Tvith bedding, if we rate it nitrogen, 

 phosphorus and potassium at the price at which they may be pur- 

 chased in such fertilizing materials as tankage, acid phosphate, or 

 steamed bonemeal and muriate of potash. 



The feeding experiments of the Ohio station have shown that in 

 feeding cattle on cemented floors we may expect to recover about 

 sixty pounds of manure and bedding per day for one thousand pounds 

 live weight, or about two pounds for each pound of air dry substance 

 in the feed. This would amount to about five tons of manure for 

 six months' feeding. 



In our experiments in the use of manure, we have obtained an 

 eighteen year average of 67 bushels of corn, 27 of wheat, and 2| tons 

 of clover hay from an application of eight tons of phosphated fresh 

 manure to the corn crop, the whole amounting to nearly eight and 

 a half tons, including the stover and straw, and the yield is steadily 

 increasing. This is being done on land that, when left continuously 

 unmanured, has produced by 36 bushels of corn, 11| bushels of wheat 

 and 2740 pounds of hay. 



