48 MANURES FOR FRUIT TREES 



are organic soils poor in mineral constituents, 

 several of which are entirely absent ; consequently 

 they are barren or sterile soils. 



Barren soils, however, can be rendered fertile 

 by the judicious use of manures. 



The following analysis, by the late Dr. 

 A. Voelcker, also illustrates the composition of a 

 barren sandy soil : — 



Organic matter 5 '36 per cent. 



Clay . . . 4-57 



Sand 89-82 



Lime . 0"25 ,, 



Alkalis and magnesia . . . 0'49 ,, 



Phosphoric acid .... a trace 



This soil would be rendered fertile by applying 

 farmyard manure and .3 cwts. of superphosphate 

 of lime, Ig- cwts. of kainit, ^ cwt. of iron sulphate 

 and 2 cwts. of sodium nitrate per acre. Nitrogen 

 is required by all fruit trees. It increases the 

 chlorophyll in the leaf, and promotes growth 

 generally. Iron is also required for the proper 

 growth of fruit trees, and if a soil is deficient in this 

 ingredient, wood, leaf and fruit are all stunted in 

 growth. Cheal states that a calcareous clayey 

 surface soil is improved by adding 1 cwt. of iron 

 sulphate per acre, as it gives colour to the fruit. 

 This is in accord with the author's investiga- 

 tions. 



