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  2. NOx - Wikipedia

    en.wikipedia.org/wiki/NOx

    Atmospheric constituents such as nitrogen oxides can be stratified vertically in the atmosphere. Ott noted that the lightning-produced NO x is typically found at altitudes greater than 5 km, while combustion and biogenic (soil) NO x are typically found near the sources at near surface elevation (where it can cause the most significant health ...

  3. Soil gas - Wikipedia

    en.wikipedia.org/wiki/Soil_gas

    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 organisms. Other natural soil gases include nitric oxide, nitrous oxide, methane, and ammonia. [3]

  4. Nitrogen cycle - Wikipedia

    en.wikipedia.org/wiki/Nitrogen_cycle

    Nitrogen is present in the environment in a wide variety of chemical forms including organic nitrogen, ammonium (NH + 4), nitrite (NO − 2), nitrate (NO − 3), nitrous oxide (N 2 O), nitric oxide (NO) or inorganic nitrogen gas (N 2). Organic nitrogen may be in the form of a living organism, humus or in the intermediate products of organic ...

  5. Nitrogen and Non-Protein Nitrogen's effects on Agriculture

    en.wikipedia.org/wiki/Nitrogen_and_Non-Protein...

    In its natural state, nitrogen exists primarily as a gas (N2) in the atmosphere, making up about 78% of the air we breathe. Nitrogen finds extensive usage across various sectors, primarily in the agriculture industry, and transportation. Its versatility stems from its ability to form numerous compounds, each with unique properties and applications.

  6. Human impact on the nitrogen cycle - Wikipedia

    en.wikipedia.org/wiki/Human_impact_on_the...

    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 ...

  7. Plant nutrients in soil - Wikipedia

    en.wikipedia.org/wiki/Plant_nutrients_in_soil

    Nutrients in the soil are taken up by the plant through its roots, and in particular its root hairs.To be taken up by a plant, a nutrient element must be located near the root surface; however, the supply of nutrients in contact with the root is rapidly depleted within a distance of ca. 2 mm. [14] There are three basic mechanisms whereby nutrient ions dissolved in the soil solution are brought ...

  8. Denitrification - Wikipedia

    en.wikipedia.org/wiki/Denitrification

    Denitrification can lead to a condition called isotopic fractionation in the soil environment. The two stable isotopes of nitrogen, 14 N and 15 N are both found in the sediment profiles. The lighter isotope of nitrogen, 14 N, is preferred during denitrification, leaving the heavier nitrogen isotope, 15 N, in the residual matter.

  9. Leaching (agriculture) - Wikipedia

    en.wikipedia.org/wiki/Leaching_(agriculture)

    how much nitrate is already present in the soil. [3] The level of nitrous oxide (N 2 O) in the Earth's atmosphere is increasing at a rate of 0.2 to 0.3% annually. Anthropogenic sources of nitrogen are 50% greater than from natural sources, such as, soils and oceans.