Nitrogen

Nitrogen  - - Soil. Organic and Natural Products - Fertilizer
Nitrogen - Soils. Organic and Natural Products - Fertilizers
Nitrogen (N) in Soil -
N = NITROGEN - For soils that are nitrogen deficient. Natural and organic sources of include : treat, manure, weeds, grass clippings, and other garden wastes with CBPA and add the resulting compost to the soil. This will result in a simultaneous improvement in humus and nitrogen content.
Nitrogen (N) is probably the most widely recognized nutrient, known primarily for its ability to “green up” lawns. Nitrogen mainly affects vegetative growth and general health. Chlorophyll, the green substance in plants responsible for photosynthesis, is largely composed of nitrogen. It is also used heavily in new shoots, buds, and leaves. Air contains about 78% nitrogen, but atmospheric nitrogen is not readily available to plants. They must absorb it through the soil. Ammonium and nitrate are both readily available forms of nitrogen, but they are common in chemical fertilizers and leach heavily and quickly out of the soil. Nitrogen can be applied organically in many ways, including composted manure, blood meal, canola meal, fish powder and various liquid organic fertilizers. Keep in mind that many organic dry fertilizers are slow-release, helping the long-term nitrogen content and building up organic matter in the soil.
Nitrogen deficiency is recognized by the yellowing of older leaves, slowing or stopping of growth. Leaves may drop sooner than expected. Excess nitrogen is recognized by extremely fast growth, resulting in long, spindly, weak shoots with dark green leaves.
Nitrate Nitrogen - N0-3-N: Nitrate nitrogen is a measure of the nitrogen available to the plant in nitrate form. In high rainfall areas, sandy soil types and areas with warm winters, this measurement may be of limited value except at planting or side dress time. In the areas with lower rainfall, the nitrate test may be very beneficial.
Organic Matter and ENR (Estimated Nitrogen Release) - Percent organic matter is a measurement of the amount of plant and animal residue in the soil. The color of the soil is usually closely related to its organic matter content, with darker soils being higher in organic matter. The organic matter serves as a reserve for many essential nutrients, especially nitrogen. During the growing season, a part of this reserve nitrogen is made available to the plant through bacterial activity. The ENR is an estimate of the amount of nitrogen (lbs/acre) that will be released over the season. In addition to organic matter level, this figure may be influenced by seasonal variation in weather conditions as well as soil physical conditions.
Soil Macro-nutrients include : nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) and sulfur (S).
pH
Nitrogen (N)
Phosphorus (P)
Potassium (K)
Calcium (Ca)
Magnesium (Mg)
Sulphur (S)
Copper (Cu)
Iron (Fe)
Manganese (Mn)
Zinc (Zn)
Sodium (Na)
Boron
Salt Salinity
N-P-K  -
Soil
Fertilizer Soil Nitrogen 2022
Fertilizers cause more than 2% of global emissions Phys.org
The interacting effects of irrigation, sowing date and nitrogen on water status, protein and yield in pea (Pisum sativum L.) | Scientific Reports Nature.com
Effect of slow-release nitrogenous fertilizers on dry matter accumulation, grain nutritional quality, water productivity and wheat yield under an arid environment | Scientific Reports Nature.com
Farming and fertilizers: how ecological practices can make a difference Phys.org