MANURES, THEIR KINDS AND USES. 19 



emitted by plants, and the more abundant the foliage, 

 the greater the quantity. By the action of this ozone, 

 the nitrogen of the air may be converted into nitric acid. 

 Perhaps the cow pea, the clover, etc., are more active in 

 this respect than any other plants. 



These preliminary observations bring me to the first 

 and most simple and cheapest manner of conveying fer- 

 tility to the soil. 



GREEN MANURING. 



As soon as life is extinct, all organic substances begin to 

 decay, and the richer these substances are in albuminoids, 

 or such as contain nitrogen, the better are they adapted for 

 fertilizing, and the more rapid will be the process of de- 

 cay. Under like circumstances, albuminoids of animal 

 origin will decompose more rapidly than those of vege- 

 table origin. All green succulent plants containing 

 saccharine and mucilaginous matters and woody fibre, fer- 

 ment readily, hence the advantage of plowing in green 

 crops, whether of natural growth, or sown for the pur- 

 pose. No plant is better adapted to be used at the South 

 for restoring fertility by green manuring than our cow 

 pea. The analyses here given show it to be rich in 

 albuminoids; it makes in our climate a heavier growth 

 than clover in any part of the world, and grows on soil 

 much too poor for a fair crop of the latter, answering 

 thus both the demands of quality and quantity. When 

 plants are in flower, they contain the largest quantity of 

 soluble matter; it is, therefore, when plowed under at 

 this season, under ordinary circumstances, that they will 

 afford the greatest amount of soluble nutritive matter. 



In heavy, impervious soils, especially, they should not 

 be turned under too deeply, or else the absence of air will 

 retard decomposition. No applications of commercial 

 fertilizers will continuously prove beneficial without the 

 presence, in the soil, of decaying vegetable matter, or hu- 



