242 BOARD OF AGRICULTURE. 



It is seldom however, that crops utterly fail from the with- 

 holding .of heat and moisture. Our fields are lean because of 

 starvation, because we do not supply through the soil, the food 

 which plants require. 



Chemistry teaches what had already been learned from obser- 

 vation and experience, that in feeding vegetable growths, the 

 kind of aliment demanded differs in different organisms. There 

 are certain great families of plants which have diversified appe- 

 tites, and they must be gratified in their tastes or they refuse to 

 bring forth their like. We know what they require, and we 

 obtain hints as regards the best method of supplying their 

 wants. 



It is safe to follow the guidance of chemistry in fertilizing 

 trees and vines. Careful examination of the wood and fruit 

 shows what substances they most largely consume. 



They differ from grains and roots not so much in the food 

 they require, as in circumstance of condition. They are placed 

 in the soil to remain for a series of years, and the consumption 

 of certain elements is to be gradual but constant. Therefore it 

 is better to supply generously the specific aliment they require, 

 and trust to soil decomposition for those articles of which the 

 structure needs but a trace. 



About twenty months since, I prepared a grape border 

 sufficiently large for thirty vines. It was arranged in strict 

 accordance with the chemical structure of the vine and fruit. 

 Lime, phosphoric acid, potash, predominate in these, therefore 

 to meet the first want, mortar from the walls of an old building 

 was used ; for the second, well rotted bone-dust ; for the third, 

 ashes. But little animal excrement was employed, decayed 

 sods supplying the needed humus. 



Entertaining the idea that it is better not to make a homo- 

 geneous mixture of border materials, they were arranged in 

 very thin strata or layers ; first of soil, then bone, then soil with 

 sand, then ashes, soil and sand again, then lime. The layers 

 constituted but a mere sprinkling, and due regard was had to 

 requisite qualities of each. 



This bed was not disturbed with the shovel after it was com- 

 pleted. Arranged in this way, it seemed reasonable to suppose 

 the roots would not be required to travel so far for food in the 

 early stages of growth, and that extending as the supply failed, 



