18 FARMERS' BULLETIN 851. 



Borax had no injurious effect on the composition of the manure; 

 in fact, in some cases the ammonia and water-soluble nitrogen seemed 

 to be increased ; nor was there any permanent decrease in the number 

 of bacteria. Borax- treated manure was less subject to the growth of 

 molds and consequent firefanging. Now, although borax does not 

 have any deleterious effect on the chemical composition of manure, 

 yet when added to the soil with the manure it acts directly on plants, 

 and large applications will cause considerable injury. On the other 

 hand, certain investigators have shown that small amounts of borax 

 have a stimulating effect. The question is, therefore, whether any 

 injury to plants will result from the application of manure treated 

 at the rate of 1 pound per 16 cubic feet. To answer this point 

 numerous tests were carried out, both in the greenhouse and under 

 field conditions, using borax-treated manure for fertilizing a number 

 of different crops, such as wheat, potatoes, peas, beans, lettuce, and 

 others. As far as these experiments have gone they indicate that if 

 manure so treated is applied at a rate of not more than 15 tons per 

 acre, no injury, as a rule, will follow. Some plants are more sensi- 

 tive to the presence of borax than others, however, and the effects 

 are more noticeable on some soils than on others. All crops have 

 not been tested, nor has the cumulative effect of borax treatment 

 been worked out. It is necessary, therefore, to repeat the warning 

 issued in connection with a previous bulletin on this subject, that 

 great care be exercised, in the application of borax, that the manure 

 does not receive more than 1 pound for every 16 cubic feet, and 

 that not more than 15 tons of manure so treated are applied to the 

 acre. 



In view of the possible injury from the borax treatment as a result 

 of carelessness in applying it, or from other unforeseen conditions, it 

 is recommended that horse manure and other farmyard manures 

 which are to be used as fertilizer be treated with hellebore. Borax, 

 on the other hand, is such a good larvicide that it can be used with 

 advantage on the ground of soil-floor stables, in privies, on refuse 

 piles, and on any accumulations of fermenting organic matter which 

 are not to be used for fertilizing purposes. 



TREATMENT WITH CALCIUM CYANAMID AND ACID PHOSPHATE. 



Many experiments with mixtures of commercial fertilizers were 

 tried to determine whether fly larvae would be killed by any sub- 

 stance the addition of which would increase the fertilizing value of 

 the manure. A mixture of calcium cyanamid and acid phosphate 

 was found to possess considerable larvicidal action. Several experi- 

 ments showed that J pound of calcium cyanamid plus J pound of 

 acid phosphate to each bushel of manure gave an apparent larvicidal 

 action of 98 per cent. The mixture in the form of a powder was 



