AirOUXT OF FARJ[-YARD MAN'URE REQUIRED. '219 



plots witli the qiuiiitity of farm-yard niaiiiirc applied, we 

 iiud :— 



Clover crops in ISS-i. 



•Cimncrsilort MUiisegast Kotitz Oberboliritzsch Oberscliijim 



Pounds . 9144 5583 1095 911 _ 



Quant iti/ of manure applied in 1851. 

 Cwt. . 180 194 229 314 897 



The field at Cunnersdorf which contained the largest 

 store of dung-constituents received the smallest ; the 

 field at Oberbobritzsch which gave the smallest crop of 

 clover, the largest quantity of farm-yard manure. 



The crop of clover, however, is not the only factor to 

 determine the amount of farm-yard dung required for 

 manuring ; for one of the clover-constituents, silicic acid, 

 which is indispensable to the cereal plants, is present 

 only in trifling proportion, and hence the quantity of 

 farm-yard manure (straw-manm-e) must bear a definite 

 ratio to the quantity of straw-constituents ah'eady present 

 in the ground. 



If, in the Saxon experiments, we compare the increased 

 produce of corn and straw obtained from the fields 

 manured with farm-yard dung, we find : — 



Increase of produce hy farm-yard manuring, per acre. 



Cunncrstlorf Kotitz Obcrbol)ritzsch 



Quantity of farm-yard manure . 180 cwt. 229 cwt. 314 cwt. 



Corn 347 lbs. 352 Ibs^ 452 lbs. 



Straw 1743 „ lOOG „ 914 „ 



The field in Cunnersdorf, manifestly the richest in sub- 

 stances nutritive for straw, gave the largest straw-crop, 

 although it had received the smallest quantity of farm- 

 yard manure. In the increased produce, corn was to 

 straw as 1 : 5, clearly showing that sparing application 

 of straw-manure was the proper course to pursue here. 

 This fact readily ex])lains also why the field at 01)('r- 



