Nitrogen Bacteria and Legumes

Nitrogen Bacteria and Legumes - With special reference to red clover, cowpeas, soy beans, alfalfa, and sweet clover, on Illinois soils

Among the several different classes or groups of bacteria there are two which are of special importance to agriculture because of their relation to the element nitrogen, this being commonly considered the most valuable element of plant food.[1] These two classes of bacteria are, first, the nitrifying bacteria, and, second, the nitrogen-gathering bacteria. The nitrifying bacteria are those which have the power to form nitrates. In the following brief discussion of this subject we include at least three species of bacteria which by their combined or successive action have the power to transform organic nitrogen into nitrate nitrogen, which is a suitable form of nitrogen for plant food. For the exact information which we now have regarding the nitrifying bacteria we are indebted to the researches of Pasteur and Schlsing and Mntz of France, Winogradsky of Russia, Warington of England, and others. The nitrogen in the soil is almost entirely in organic compounds; that is, the nitrogen (which is a gas in the free, or uncombined, state) is united or combined with other elements, notably with carbon, hydrogen, and oxygen, in the form of partially decayed vegetable or organic matter. (By organic matter we mean matter which has been formed by the growth of some organism, either plant or animal, as grass or flesh.) Plants cannot use the free nitrogen of the air as plant food, neither can they use the organic compounds of nitrogen which occur in the soil. There[308] are at least three different kinds of bacteria, and also three different steps or stages involved in the process of nitrification, the nitrogen being changed from the organic compounds first into the ammonia[2] form, second, into the nitrite form, and third into the nitrate form. During the process the nitrogen is separated from the carbon and other elements composing the insoluble organic matter, and is united or combined with oxygen and some alkaline element (as calcium) to form the soluble nitrate, such as calcium nitrate, which is one of the most suitable compounds of nitrogen for plant food. Calcium is the alkaline element contained in lime or limestone. The name calcium nitrate indicates just what elements this compound contains; namely, calcium, nitrogen, and oxygen. (In the names of compounds the ending -ate always means oxygen.) ......Buy Now (To Read More)

Product details

Ebook Number: 56472
Author: Hopkins, Cyril G. (Cyril George)
Release Date: Jan 31, 2018
Format: eBook
Language: English