TVlTH AND WITHOUT MANURE. 



39 



years, the following is the weight in pounds of 

 an average crop : — 



The soils here are exactly similar and in the 

 same field, strong land on clay with a sub- 

 stratum of chalk ; the management is the same, 

 in so far as culture is concerned ; both crops are 

 kept equally clean and free from weeds, the 

 same seed is used, and they are exposed to the 

 same changes of weather. The only difference 

 is, that in the one case nature has for thirty 

 years been unassisted by manure, and in the 

 other the soil receives every year the various 

 kinds of manure which have been found most 

 suitable to the crop. The result of this treat- 

 ment is a return of three times the weight 

 of corn and four times the weight of straw, 

 for an expenditure in manure which leaves a 

 profit of 100 per cent, on its cost. In both 



