MANURING ORCHARDS. 161 



factory growth cannot be obtained, and if the soil is in any waj' 

 deficient in organic matter, the amount of nitrogen will probably 

 be rather small. As a rule, a bearing orchard should have, once 

 in two years, from 300 to 500 pounds of ground bone, 200 to 300 

 pounds of muriate of potash, and 150 pounds of nitrate of soda 

 per acre ; or in place of these 25 tons of decomposed stable 

 manure will be beneficial if the soil is light. In addition to 

 their value for supplying plant food, the chemical fertilizers have 

 an additional value, which is, perhaps, equally important, as, by 

 supplying soluble plant food early in the season, they enable trees 

 to make their growth during the first of the season and ripen their 

 wood thoroughly before winter. The growth is, as a rule, much 

 more firm than that obtained by the use of stable manure, or from 

 the natural fertility of the soil. In fact the chemical manures can 

 be used as correctives, since if those containing potash and phos- 

 phoric acid are added to soils that have been highly enriched with 

 stable manure, or that are naturally quite rich in organic matter, 

 they will have a tendenc}' to make the new wood more firm and 

 compact. It can then be claimed that the proper use of chemical 

 manures will increase the hardiness of the trees, and will both 

 render the fruit buds less susceptible to sudden changes in the 

 weather, and lessen the danger of their winter-killing." 



These statements, while general rather than specific in charac- 

 ter, agree in their main points : First, that orchards should be 

 liberally- fertilized ; second, in giving prefei'ence to artificial 

 manures ; and third, in urging that great care be exercised in the 

 use of nitrogen. Those in reference both to the unfavorable 

 effect of too much nitrogen, and to the importance of superphos- 

 phate and potash salts, are in a measure verified by the New 

 Jersey experiment already quoted, — that is, nitrogen used alone 

 and, therefore, in excess, was not particularly useful, while the 

 combination of phosphoric acid and potash was more serviceable 

 than any other combination of two elements. The nitrogen was, 

 however, of very great value when used in connection with the 

 mineral elements, as the accompanying statement will show. 



VI. — Money Value of Crops, Less Cost of Manure. 



Per year. 



Unmanured, 10 years, value of crop, $301.85 .... $30 18 

 Nitrogen alone, 10 years, value of crop, $307.30 ... 30 73 



