8 BOARD OF AGRICULTURE. 



the growth of their roots, they seek out such substances as are 

 adapted to their nourishment. Hence it follows that in order 

 to produce the best result in the production of any crop, the 

 food intended for it should be so placed as to be at once and 

 always available to the plants. To ascertain where this is, we 

 must find the distance to which various plants send their roots 

 in search of food. It may be enough for our present purpose 

 to state, that the roots of all our commonly cultivated plants 

 extend to, and interlace with, those of the neighboring plants, 

 so that, practically, the whole ground is occupied with roots 

 before the plants are fully grown. These roots are not made 

 up of simply single, horizontal branches, but by their subdivision 

 into rootlets and fibres, seek for nourishment upwards, down- 

 wards, and in all directions, more or less completely filling the 

 ground from the immediate surface to a depth dependent upon 

 the condition of the deeper soil. Hence it may be laid down 

 as a rule universally applicable, everywhere, and under 1 

 circumstances, that the more thoroughly and intimately the 

 plant food is diffused through and mixed with the soil, the 

 greater will be the growth of any plant placed therein in a given 

 time. 



Here the question suggests itself, "What is the food of plants '( 

 It is generally conceded that plants are incapable of taking up 

 substances by their roots, unless such substances are in a state 

 of solution. Plants may be said to drink, but never to eat. 

 All their food is taken up dissolved in water, and until it is 

 soluble in water it is not plant food. A manure heap, as we 

 ordinarily find it, is a compound of the excrementitious matter 

 of animals, mixed with straw. According to the investigations 

 of Dr. Voelckcr, chemist of the Royal Society of England, 

 fresh manure of this kind contained nearly twelve per cent, of 

 its dry matters in a soluble form. After six months' fermen- 

 tation, the soluble matters had increased to upwards of twenty- 

 one per cent. What we usually call manure, then, is only in 

 part fitted for the nourishment of vegetable growth. As fast 

 as it decomposes and becomes soluble, just so fast it becomes 

 plant food. 



Keeping these views in mind, we are now prepared to ask the 

 question, how is manure to be applied to the land, in order to 

 present its nutritious portions to plants in the most profitable 



