160 MANURES. 



ingredients contained in the ash of plants ; it contains 

 plenty of organic matter ; and it contains no one of 

 the mineral substances, as oxide of iron or common 

 salt, in such quantities as would be likely to prove 

 hurtful. The second has also a large supply of or- 

 ganic matter ; and it has all the mineral substances 

 required for any crop, except potash, soda, and chlo- 

 rine. This also is free from any hurtfal excess of one 

 or two ingredients. The amount of oxide of iron in 

 it is more favorable even than in the first soil. 

 When we look at the third, we find it not only desti- 

 tute of those ingredients which are the most expen- 

 sive to furnish, but abounding in oxides of iron to an 

 injurious extent. 



279. The owner of three such soils as the foregoing, 

 could he be informed how they are constituted, would 

 naturally cultivate crops of the most valuable kind on 

 the first, as wheat, corn, clover. With regard to the 

 second, he would look into the analyses of crops, and 

 select for it those which contain least of those mineral 

 matters in which the soil is deficient. After selecting 

 a rotation for perhaps three years, he would next 

 inquire how the wanting ingredients could be most 

 readily supplied. If he were to resort to barn-yard 

 manure, he would supply to the land a large amount 

 of organic matter which this land does not need, be- 

 cause already well supplied with it. He would also 

 supply several mineral substances with which the soil 

 was before abundantly supplied ; and he would fur- 

 nish in this way but comparatively little of those 

 ingredients which are really wanted. The use of 



