CHEMICAL CORN-GROWING. 97 



I think a careful examination of what appears here, and I 

 know of no contradictory evidence elsewhere, will satisfy any 

 candid mind, that the use of chemical fertilizers need not 

 necessarily be destructive to land. 



After this presentation of our experiment, it may be useful 

 to consider each element of our fertilizer separately, and 

 applying such knowledge as we possess, indicate the manner 

 in which they are supposed to have acted in the soil. 



Sulphate of ammonia.* When first applied, it remained 

 inert until it became dissolved either by the moisture of the 

 soil or by rains ; as soon as dissolved, the soil commenced to 

 act upon it, separating it into its component parts, sulphuric 

 acid and ammonia. The ammonia became somewhat fixed 

 within the soil, for most soils have some retaining power over 

 ammonia, and even on highly-farmed land, but a third escapes 

 with the drainage. The sulphuric acid, after its separation 

 from the ammonia, passed downward with the water, and 

 probably in combination Avith lime passed into the subsoil. 



It is a curious fact that, although ammonia is largely 

 retained by the soil, thus furnishing a supply of nitrogen for 

 the growing crop, yet if the nitrogen be supplied in the form 

 of nitric acid, this passes readily through the soil, and escapes. 

 Thus, if nitrate of soda be applied in solution to a soil, both 

 the acid and the base penetrate the soil, and pass downward 

 with the water of filtration. If nitrate of potash be in like 

 manner applied, the potash is in large measure retained, but 

 the nitrogen pursues its path downward with the water. We 

 thus see, that when nitrogen is supplied to the soil through 

 an acid, rather than a base, the progress downward with the 

 water is free, and consequently it can be in a position to afford 

 nutriment to the plant for but comparatively a short time. 

 Nitric acid may, however, be retained longer in some soils 

 than others ; but in a light soil, such as ours, theory bids us 

 avoid nitrogen in the form of an acid, and seek it in the form 

 of a base. Hence the sulphate of ammonia is the preferable 

 source of supply over nitrate of soda. 



* Sulphate of ammonia is not entirely retained by soils, but only largely : nitrate 

 of soda but little. Under conditions as they occur in England, chemical nitrogen is 

 disposed of as follows : One-third to the crop, one-third remains inert in soil, and one- 

 third is lost through drainage. 



13* 



