Search results
Results from the WOW.Com Content Network
Nitrogen is the most critical element obtained by plants from the soil, to the exception of moist tropical forests where phosphorus is the limiting soil nutrient, [36] and nitrogen deficiency often limits plant growth. [37] Plants can use nitrogen as either the ammonium cation (NH 4 +) or the anion nitrate (NO 3 −).
Plant nutrition is the study of the chemical elements and compounds necessary for plant growth and reproduction, plant metabolism and their external supply. In its absence the plant is unable to complete a normal life cycle, or that the element is part of some essential plant constituent or metabolite .
This is especially important when nitrogen fertilizer is not used, as in organic rotation schemes or in some less-industrialized countries. [8] Nitrogen is the most commonly deficient nutrient in many soils around the world and it is the most commonly supplied plant nutrient. The supply of nitrogen through fertilizers has severe environmental ...
Rhizobium is a genus of Gram-negative soil bacteria that fix nitrogen. Rhizobium species form an endosymbiotic nitrogen-fixing association with roots of (primarily) legumes and other flowering plants. The bacteria colonize plant cells to form root nodules, where they convert atmospheric nitrogen into ammonia using the enzyme nitrogenase.
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 ...
Most plant nutrients, with the exception of nitrogen, originate from the minerals that make up the soil parent material. Some nitrogen originates from rain as dilute nitric acid and ammonia, [44] but most of the nitrogen is available in soils as a result of nitrogen fixation by bacteria. Once in the soil-plant system, most nutrients are ...
Biological soil crust in Natural Bridges National Monument near Sipapu Bridge. Biological soil crusts cover about 12% of the earth's landmass. [8] They are found on almost all soil types, but are more commonly found in arid regions of the world where plant cover is low and plants are more widely spaced.
In wetlands, nitrogen is used by the vascular and non-vascular vegetation to grow, therefore removing the nitrogen naturally and preventing a large amount of nitrogen from entering the coastal region creating anoxic habitats in the ocean. [28] Conservation of the brackish marsh wetlands can be a last resort to help prevent these potential problems.