64 Bush-Fruits 



with potash and other bases which leach away if not taken 

 up by plants, thus depleting the soil of basic ingredients. 

 The use of less manure, supplemented with chemical? 

 containing phosphoric acid and potash, is often wiser. 



According to the analysis of raspberries published from 

 Washington 1 a crop of one hundred bushels of raspberries 

 would remove only about six pounds of nitrogen, twenty 

 pounds of phosphoric acid and fourteen pounds of potash 

 from the soil. This being true, the importance of fertili- 

 zers may be easily overestimated. Fifty pounds of nitrate 

 of soda or slightly more of dried blood, one hundred and 

 fifty pounds of acid phosphate and fifty pounds of muriate 

 of potash would more than supply this need. The un- 

 avoidable losses in the soil make it necessary to furnish 

 more than the plants take away; yet this may serve as a 

 suggestion regarding the possible demands. The individ- 

 ual qualities of the soil may modify the validity of cal- 

 culations of this sort, since soils differ so much. 



One factor in soil-fertility is not supplied by chemicals. 

 That factor is humus, a more important one than the 

 others. In this stable-manure has the advantage, but the 

 same results may be obtained by the judicious use of 

 green-crops before planting and of cover-crops afterward. 



PROPAGATION 



In practice, there is but one way of propagating black- 

 caps. That is from the tips formed where the ends of 

 the canes take root. Plants can be grown from root- 

 cuttings, or by burying the entire cane and cutting it 

 1 Year Book, Dept. of Agr., 1895, 568. 



