What is the role of microorganisms in soil fertility nitrogen cycle and effect of denitrifying bacteria on soil fertility?
The roles of soil microorganisms in soil fertility nitrogen cycle can not be overemphasized.The pseudomonas converts organic N to ammonium N, nitrosomonas converts ammonium nitrate to NO2 and nitrobacter converts NO2 to nitrate form which is taken up plants for good growth and yield.The roles of bacteria in symbiotic N fixation ís also important and enhances healthy root growth as noticed in legumes root nodulates.The effects of denitrifying bacteria are important because in a flooded agricultural fields Rhidospirillus a denitrifying bacteria will convert soil nitrates to atmospheric nitrogen which is a loss in soil nitrogen,also,it will encourage the presence of sulphide in the soil which encourage production of acidic soils through reduction in soil pH, also, the acidity will increase fixation of soil P and increases soil micronutrients.All of them affect soil fertility maintenance and disruption of good soil health
Yes, soil microbes catalyze most of the transformations of soil nitrogen into plant-usable forms. Diverse microbes use different processes and sometimes work together. Knowing the various styles of soil microbes, and linking microbes to specific soil processes, can be important knowledge for farmers. Bacteria play a central role: Nitrogen-fixing bacteria, which convert atmospheric nitrogen to nitrates. Bacteria of decay, which convert decaying nitrogen waste to ammonia and nitrifying bacteria, which convert ammonia to nitrates/nitrites. The process of fixing the atmospheric nitrogen into the soil is called nitrogen fixation. Microorganisms like Rhizobium are present in the root nodules of the leguminous plants.Bacteria such as Rhizobium, Azotobacter, and certain blue-green algae present in the soil fix atmospheric nitrogen in the soil. But Rhizobium plays a vital role in nitrogen fixation. Microbes are critical in the process of breaking down and transforming dead organic material into forms that can be reused by other organisms. This is why the microbial enzyme systems involved are viewed as key 'engines' that drives the Earth's biogeochemical cycles. Nitrogen-fixing bacteria are prokaryotic microorganisms that are capable of transforming nitrogen gas from the atmosphere into “fixed nitrogen” compounds, such as ammonia, that are usable by plants. The rhizosphere serves as the microbial seed bank where microorganisms transform organic and inorganic substances in the rhizosphere into accessible plant nutrients as plants harbor diverse microorganisms such as fungi, bacteria, nematodes, viruses, and protists among others. The process of denitrification can lower the fertility of soil as nitrogen, a growth-limiting factor, is removed from the soil and lost to the atmosphere. This loss of nitrogen to the atmosphere can eventually be regained via introduced nutrients, as part of the nitrogen cycle. The positive effect of denitrification is that it decreases the leaching of nitrate to ground and surface waters. The negative effect is that denitrification is a major source of the greenhouse gas N2O and a loss of N otherwise available for the growth of plants. Bacteria increase soil fertility through nutrient recycling such as carbon, nitrogen, sulphur and phosphorus. Bacteria also help in the decomposition of dead organic matter and then give out simple compounds in the soil, which can be used up by plants. Denitrification is a microbial process occurring in soils, both producing and consuming the potent greenhouse gas nitrous oxide (NO), competing for nitrate with plants and hydrological leaching pathways, removing nutrients and reactive nitrogen from the biosphere, and closing the global nitrogen cycle. Denitrifying bacteria, microorganisms whose action results in the conversion of nitrates in soil to free atmospheric nitrogen, thus depleting soil fertility and reducing agricultural productivity.
Soil microorganisms help in the decomposition of organic matter to release plant nutrients such as nitrogen for growth and yield. No microorganisms in the soil, no life.
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