490 INFLUENCE OF THE METHOD OF CULTDRE, 



In each of these cases, therefore, and especially in the last, a striking 

 difference presented itself both in the absolute and in the relative weights 

 of grain and of straw reaped under precisely similar circumstances, by 

 the use of different varieties of the same species of seed. Nor are the 

 above by any means extreme cases. In the same field I have known 

 the Golden Kent and the Flanders Red varieties, sown in the sarne 

 spring, to thrive so differently, that, while the former was an excellent 

 crop, the latter was almost a total failure. It will require a very refined 

 chemistry to explain the cause of such diversities as tliese. 



§ 3. Influence of the method of culture upon the produce of food. 



In addition to the circumstances above alluded to, the quantity of food 

 tliat is raised depends very much upon the method of culture which is 

 adopted. Thus, in land of medium quality, our opinion in regard to the 

 quantity of food it is likely to yield would be greatly affected by the 

 answers we should obtain to the following questions ; — 



1°. Is the land in permanent pasture, or is it under the plough? — 

 With the exception of rich pasture, it is said that land, under clover or 

 turnips, will produce three times as much for cattle as when under grass. 

 If such a green crop then alternate with one of corn, the land would 

 every two years produce as much food for stock as it would during three 

 years if lying in grass, besides the crop of corn as food for man, and 

 of straw for the production of manure. 



This statement may possibly be a little exaggerated, or may represent tru- 

 ly the comparative produce of food in special cases only — yet there seems 

 sufficient reason for believing, as a general rule, that a very much larger 

 amount of food may be reaped from land under arable culture, than 

 when laid away to permanent pasture. 



2°. What kind and quality of manure is applied 1 — Every practical 

 man knows the importance of manuring his land, and how much the 

 abundance of every crop he sows depends both upon the quantity and upon 

 the kind of manure he is able to add to it. 



3°. In what way is it applied ? — But much depends also upon the 

 manner in which the manure is expended, or the kind of crop to which 

 it is applied. 



I have already (p. 477) directed your attention to the loss which must 

 necessarily be sustained by top-dressing with farm-yard manure, and yet 

 how in certain modes of cropping and manuring the land, it may be 

 not only advisable but necessary to do so. Yet the comparative return 

 of food obtained from the use of such manure, when applied as a top- 

 dressing to grass land for instance, and when buried with the turnip crop 

 in the usual manner, is very unlike. 



Thus, suppose an acre of grass land, of such a quality as to produce 

 annually without manure 1| tons of hay, to be top-dressed ^ery spring 

 or autumn with 5 tons of farm-yard manure per acre — and suppose 

 another acre of the same land in arable culture to be manured for turnips 

 with 20 tons of farm-yard manure at once. Then the grass land, by 

 the aid of the manure, would not produce more than double its natural 

 crop, or 2^ tons an acre, that is, 10 tons of hay in the four years. This, I 

 believe, is making a large allowance for the effect of the manure. 



But the arable land, in the four years, if of the same quality, may be 



