CHEMICAL CORN-GROWING. 



95 



also pointed out that the crop cannot remove from the soil all 

 the fertilizer applied. Therefore, in practice, in applying to 

 the soil what we expect a large crop to remove, we do not 

 obtain necessarily the large crop that we expect, and the 

 balance of fertile element is retained in the soil ; or should 

 the large crop be obtained, it is not produced from, although 

 it may be caused by, the chemicals we apply. 



However, we can answer this question for the practical 

 farmer, in a practical way. If we look over the experiments 

 at Rothamsted in England, we find on record one experiment 

 in growing wheat on the same land for twenty years without 

 manure. We present the yields in full, as indicating how 

 much fertility may be depended upon to be furnished by 

 climatic and natural influences in each year, from some 



soils : — 



Winter Wheat. 



Average for first ten years, 15 bushels 3 pecks ; for second ten years, 

 16 bushels 2 pecks. Average for the 20 years, 16.2 bushels. 



The land is what may be called in England, fair average 

 wheat land, and under ordinary management in the district 

 may be rated at from twenty-five to twenty-seven bushels per 

 acre. The soil is a somewhat heavy loam, with a subsoil of 

 raw yellowish clay resting upon chalk, which furnishes good 

 natural drainage. 



In another plot, marked 16a in Mr. Lawes' tables, portion 

 of the same experimental field given above, we have the yearly 

 crops, for twenty years, as given below, the manure used being 

 entirely chemical. In transcribing, I give the result approxi- 



