410 State Horticultural Society. 



lation, there is no need for the employment of a very quick acting, 

 readily available and high-priced dissolved bone black; besides, the 

 cheaper form of acidulated rock will furnish quite as readily available 

 phosphoric acid. 



Under many circumstances the choice would lie between the two 

 forms of bone meal, namely, pure raw bone meal, and steamed bone 

 meal. The essential differences are, the raw bone meal is more readily 

 available, contains a higher content of nitrogen, from 3 to 4 per cent, 

 and a smaller content of phosphoric acid, from 18 to 22 per cent, and 

 these ingredients cost somewhat more per pound than in the steamed 

 bone. Steamed bone is the residue after the extraction of the glue from 

 the bone, and leaves it poorer in nitrogen, containing only from i^ to 

 234 per cent, but richer in phosphoric acid, containing from 23 to 26 per 

 cent, but neither of these ingredients is so readily available, the fertilizer 

 being what would be termed slow acting, and is the cheapest form of 

 finely ground bone. 



At the present time the cheapest source of phosphoric acid is the 

 finely ground raw rock, which contains from 28 to 32 per cent of phos- 

 phoric acid, and will cost, laid down at an average point in Missouri, 

 about $7.50 or $8.00 a ton, in car lots. This means that a ton of rock 

 contains from 560 to 650 pounds of phosphoric acid, making this ma- 

 terial cost, laid down at the farmer's station, 1.2 to 1.3 cents a pound. 



If the orchardist buys this material after it has been treated with 

 sulphuric acid, the best that he can hope for is for a ton to contain 300 

 pounds of phosphoric acid, for which he will be obliged to pay, laid 

 down at his station, from $15.00 to $18.00, which means that the avail- 

 able phosphoric acid in this form will cost from 5^ to 6 cents per 

 pound. In other words, for the same money that 300 pounds of available 

 phosphoric acid can be purchased, about 1270 pounds of unavailable ma- 

 terial can be secured, or about half the quantity usually found in the first 

 ten inches of an acre of our good land. 



Experiments conducted at the Pennsylvania Experiment Station and 

 a number of other places, extending over a long series of years, clearly 

 indicate that this material can be renderd available rapidly enough for 

 all crop requirements by good tillage and by keeping a goodly supply 

 of humus in the soil, both of which are necessary for other reasons in 

 orchard management. 



In the matter of the amount of phosphoric acid to apply, it will 

 depend necessarily upon the extent to which the soil has been depleted 

 and the age and condition of the orchard, and what other crops are in the 

 near future to be removed. If the trees are just coming into bearing 



