44 



THE MANURING OF ARABLE LAND 



[CH. 



There are two common cases: 



(1) 40 bushel crops possible, 30 bushels or less usual. There 

 is a great amount of land of this description, e.g. much of the 

 boulder clay of the Midlands and the flinty clay of the Home 

 Counties. In days gone by it was accounted good wheat land, and 

 the old men still tell of wheat crops growing so vigorously in the 

 spring that they had to be eaten down by sheep because they 

 threatened to be too rank, but nevertheless coming out well in 

 the end. Dung, of course, was liberally supplied in autumn and 

 often top dressings of soot in spring. 



When the bad times came the pride in wheat growing was 

 lost. For years wheat had to do without farmyard manure and 

 it only got a spring dressing when it was looking really bad. 

 This is all changed by the war. Wheat is so high in price that 

 it can now go back to the place it had in the farming of the 'sixties. 

 But the methods have obviously to change : farmyard manure is 

 wanted for potatoes and roots, and soot cannot always be had. 

 Their place must be taken by a dressing of artificials. 



In ordinary circumstances the increase produced by a spring 

 dressing may cost more than it is worth, but at the present time the 

 risk may well be taken. The Rothamsted results are as follows : 



Influence of increased dressings of Nitrogenous Manures on Yield 

 of Wheat, Broadbalk Field ; Average of 61 years 1852-1912. 



Mineral manure alone 



Mineral manure + 200 Ibs a 

 monium salts ... 



Mineral manure + 400 Ibs a 

 monium salts ... 



Mineral manure + 600 Ibs am- 

 monium salts 36-6 4-5 41-1 



8-2 



Cost and Value of Increased Produce. 



(a) Ordinary circumstances. Wheat at 305. Straw at 20s. 



Value of increase ... 

 Cost of extra manure 



Profit on extra manure 



15 11 



1 14 10 



1 13 10 



