176 



MANUEES AKD MANUBINd. 



The fruit-grower, having secured fruit trees and vines suitable 

 for the purpose he has in view, will find few more profitable invest- 

 ments than the expenditure of a few shillings per acre in suitable 

 manures for the purpose of adding to the fertility of the soil or 

 restoring the elements of plant food extracted from it by the crop. 



The science of agricultural chemistry has thrown such light on 

 the question of fertilisers and in the study of the requirements of 

 cultivated plants that we are now able, with a certain amount of 

 certainty, for every pound spent in suitable manures to expect a 

 good return. 



Few soils can do without manure of some sort in order to yield 

 a maximum crop. Occasionally some, however, are, if anything, too 

 rich and too forcing for the purpose of fruit-growing; they induce an 

 extravagant growth of leaves and wood to the detriment of the 

 fruit. Wine grapes on such soils produce a thin must of little value 

 for the purpose of wine-making as compared with must from similar 

 grapes grown on poorer ground. 



Most soils respond liberally to the application of suitable 

 manures, and in order to satisfy the requirements of the crops 

 entrusted to them, some knowledge of what is plant food and how 

 plants feed must necessarily prove helpful. 



WHAT is PLANT FOOD. 



Plants, in order to live and fructify, require certain elements 

 of food, fourteen in number, some of which are supplied by 

 the air, and some are found in the soil. Those supplied from the 

 air are combinations and compounds of carbon, hydrogen, and 

 oxygen, they constitute, with the compounds of nitrogen and 

 sulphur, which, in the case of fruit trees, are drawn from the soil, 

 the organic part of the plant, which on combustion, either by fire, 

 fermentation or putrefaction, return entirely or partly to the air. 

 The mineral part of the plant which is represented by the ashes 

 left behind after complete combustion constitute the inorganic 

 constituents, they consist of potassium, phosphorus, calcium, 

 magnesium, iron, silicon, sulphur, sodium, chlorine, and manganese. 



Some knowledge of the composition of the tissues of plants and 

 fruits will be useful for understanding in what proportion the 

 different elements indispensable for plant growth occur in most 

 crops. 



Nearly two-thirds consist of water which disappears on dessi- 

 cation, and the balance is made up of combustible organic matter 

 (carbo-hydrates), such as fibre, starch, sugar, gum, oils, alkaloids, 

 and albuminoids, gluten, albumen, etc. ; and also one to three per 

 cent, of mineral or inorganic matters represented by the ashes. 



