14 



ESSAY. 



These statements may serve to explain some of the 

 apparently contradictory results arising from the appli- 

 cation of special manures. A farmer gives a piece of 

 land a dressing of lime. The effect of lime is to render 

 a portion of the humus in the soil, soluble, and vegeta- 

 tion appropriating it, a large crop is the result. Hence 

 the inference, that lime is a valuable manure. He 

 therefore repeats the application the following season, 

 but neglects to use any humus producing material in 

 connection with it. The crop in this case falls short 

 of his expectation. A third trial exhausts nearly all 

 the humus in the soil, and the land becomes barren. 

 Hence, lime exhausts the soil. If there had been 

 applied the second season an amount of humus equiva- 

 lent to the quantity appropriated by the first crop, 

 there would have been little or no falling off in the 

 product. 



The practical view deducible from these considera- 

 tions is, that humus, or vegetable matter in a state or 

 condition of decay, is the great want in the way of 

 successful agriculture. Without humus, soil is abso- 

 lutely barren. With an abundance of it, any crop 

 may be grown by means of some of the artificial 

 manures as additions. The soil of the Western prairies 

 is made up in great measure of humus, the product of 

 ages of decayed vegetation. A growing crop takes 

 humus from the soil, but if allowed to mature and decay 

 where it grows, there comes to be an absolute addition 

 of humus to the soil, and the land becomes richer and 

 capable of giving larger results. Where this action 

 goes on from year to year and from century to century, 

 as in the case of the prairies, the upper portion of the 



