10 Dei'.. 1917.] Fertilizers in the Orchard. 765 



FERTILIZERS IN THE ORCHARD. 



In M jiaper dealing with fertilizers in the orchard, read before a 

 recent niccting of the Spencer Branch of the Agricultural Bureau of 

 New South Wales, Mr. TJeuben Daniel said that many farnier.s and 

 orchardists fought shy of manuring, contending that it cost too much. 

 For others it held a certain amount of mystery. With these contentions 

 he did not agree. Fertilizers should be regarded as a means of supply- 

 ing plant food, and if the increased returns were figured out it would be 

 realized that it was cheaper to manure than to leave the land hungry. 

 It was quite impossible to get full development of the soil's resources 

 without thorough cultivation. A deficiency of plant food could not be 

 made good by even the most perfect cultivation alone. 



For practical purposes it might be said that the chief constituents 

 of plant food were three in number — nitrogen, phosphoric acid, and 

 potash. For this reason the principal manures were divided into three 

 classes — (1) nitrogenous manures, containing chiefly nitrogen; (2) 

 phosphatic manures, containing phosphoric acid; (3) those containing 

 potash. 



Nitrogen was very important because it entered largely into the 

 composition of a fertile soil. Most plants derived nitrogen from the 

 soil, although a few — such as lucerne, peas, beans, clover, &c. — got a 

 large share from the atmosphere. It was a matter of determining the 

 elements of plant food which required replenishing in the soil. Some 

 manures, such as dried blood, sulphate of ammonia, nitrate of soda, and 

 superphosphate were quickly dissolved in damp soil, and thus entered 

 into action soon after application. For this reason they were best 

 ai>i)licd in the spring, while, on the other hand, boncdnst, guano, and 

 sulphate of potash took longer to dissolve; therefore it was advisable 

 to apply them in the autumn, and they were then ready to be absorbed 

 by the plants in spring, when the growth was faster. 



Some orchardists used bonedust only, others blood and bone. This 

 was a grave error. Bonedust contained no potash, which was a very 

 important constituent of all fruits. Bonedust and blood and bone could 

 suj^ply nitrogen and phosphoric acid, but potash must be added if a 

 good crop was to be assured. 



Mr. H. J. Woodbury expressed the opinion that orange and man- 

 darin trees growing in virgin soil required more potash than nitrogen, 

 while lemons required more nitrogen. Apples, pears, and ]ieaches re- 

 quired phosphoric acid and potash, and if the .soil happened to be 

 deficient in these properties, a heavy dressing would be needed. Cover 

 crops of pears, and, in fact, of any of the legume family of plants, if 

 ploughed in at the correct time, would supply the soil with nitrogen. 



— Frvit World of Australasia — May, 1917. 



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