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Nitrogen deficiency is a deficiency of nitrogen in plants. This can occur when organic matter with high carbon content, such as sawdust, is added to soil. [1] Soil organisms use any nitrogen available to break down carbon sources, making nitrogen unavailable to plants. [1] This is known as "robbing" the soil of nitrogen.
Nitrogen directly affects soil respiration in several ways. Nitrogen must be taken in by roots to promote plant growth and life. Most available nitrogen is in the form of NO 3 −, which costs 0.4 units of CO 2 to enter the root because energy must be used to move it up a concentration gradient. Once inside the root the NO 3 − must be reduced ...
The total nitrogen content depends largely on the soil organic matter content, which in turn depends on texture, climate, vegetation, topography, age and soil management. [40] Soil nitrogen typically decreases by 0.2 to 0.3% for every temperature increase by 10 °C. Usually, grassland soils contain more soil nitrogen than forest soils, because ...
Nitrogen is plentiful in the Earth's atmosphere, and a number of commercially-important agricultural plants engage in nitrogen fixation (conversion of atmospheric nitrogen to a biologically useful form). However, plants mostly receive their nitrogen through the soil, where it is already converted in biological useful form.
Nitrogen fixed by crusts has been shown to leak into surrounding substrate and can be taken up by plants, bacteria, and fungi. Nitrogen fixation has been recorded at rates of 0.7–100 kg/ha per year, from hot deserts in Australia to cold deserts. [11] Estimates of total biological nitrogen fixation are ~ 49 Tg/year (27–99 Tg/year). [10]
Approximately 78% of Earth's atmosphere is N gas (N 2), which is an inert compound and biologically unavailable to most organisms.In order to be utilized in most biological processes, N 2 must be converted to reactive nitrogen (Nr), which includes inorganic reduced forms (NH 3 and NH 4 +), inorganic oxidized forms (NO, NO 2, HNO 3, N 2 O, and NO 3 −), and organic compounds (urea, amines, and ...
Soil gases (soil atmosphere [1]) are the gases found in the air space between soil components. The spaces between the solid soil particles, if they do not contain water, are filled with air. The primary soil gases are nitrogen, carbon dioxide and oxygen. [2] Oxygen is critical because it allows for respiration of both plant roots and soil ...
In general, organic matter contacting soil has too little nitrogen to support the biosynthetic needs of the decomposing soil microbial population. If the C:N ratio of the decomposing organic matter is above circa 30:1 then the decomposing microbes may absorb nitrogen in mineral form as, e. g., ammonium or nitrates. This mineral nitrogen is said ...