Nitrates are one of the commonest plant nutrients, applied either as artificial fertilisers or organic manures. Nitrogen

Nitrogen is an essential component of proteins and it is normally absorbed by plants as inorganic chemicals, usually as nitrates. Nitrogen deficiency shows as poor growth and a general light green colour. Nitrogen is mobile nutrient. Nitrogen fixation

Although the atmosphere consists mainly of nitrogen, plants are unable to absorb it directly. Many micro-organisms fix atmospheric nitrogen in forms that plants can use, but the most important by far are the nitrogen-fixing nodules formed by Rhizobium on the roots of legumes. Nitrogen-fixing root nodules

Nodules formed on the roots of plants of the botanical family Leguminoseae, by bacteria called Rhizobium. These nodules are able to convert atmospheric nitrogen into protein. This is a symbiotic association in which the bacteria provide protein, and the plant provides carbohydrates. This is one of the reasons why pulses and fodder legumes are such valuable crops. It is possible to isolate the bacteria from these nodules, and culture them in order to inoculate the seed of leguminous crops. Commercial cultures of Rhizobium are known as legume inoculants. Some species of legume have Rhizobium strains in common, while other have their own special strains. It has become fashionable to use the plural name 'Rhizobia' but this usage should be discouraged. We might just as well refer to crocuses as 'croci'. Nitrogenous fertilisers

All crops need nitrogenous fertilisers, either in the form of artificial fertilisers, organic manures, green manures, or by nitrogen-fixing micro-organisms and legumes. Nocturnal

During the hours of darkness, as opposed to diurnal. Node

A joint in a plant stem that bears one or more leaves, usually with an axillary bud between the petiole and the stem.

Growing Soilless

Growing Soilless

This is an easy-to-follow, step-by-step guide to growing organic, healthy vegetable, herbs and house plants without soil. Clearly illustrated with black and white line drawings, the book covers every aspect of home hydroponic gardening.

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