What Neutralizes Nitrogen in Soil?

Nitrogen Cycle

• Nitrogen levels fluctuate because of environmental factors and the introduction of organic matter into soil. These factors contribute to the nitrogen cycle, a biological system that introduces, removes and reintroduces nitrogen into soil. Nitrogen enters soil through atmospheric gases, rainwater, pollution and organic matter. Once in soil, nitrogen is processed by bacteria and other microorganisms into ammonium and nitrates. Ammonium and nitrates are used by plants during the growing process. After plants grow, they die and their organic matter returns to the soil, along with nitrogen. Limiting the amount of organic matter in soil is one way to limit the amount of nitrogen in soil. Bacteria take in nitrogen during the transformation from nitrogen to nitrates and ammonium. This "locking" of nitrogen takes the nitrogen out of the soil, essentially neutralizing it. Groundwater and rainwater wash nitrogen from upper soil levels and also help in neutralizing the amount of nitrogen present in soil.

Organic Nitrogen

• Organic nitrogen enters soil through animal and plant waste. Fresh manure provides highly concentrated forms of nitrogen that can potentially harm soil structure and burn young plant's root systems. Fresh manure is neutralized, over time, as it degrades. Bacteria and microorganisms are essential to the degradation process. They are also essential to the neutralization of nitrogen. Bacteria and microorganisms consume nitrogen, lessening the amount present. They transform it into inorganic nitrates and ammonium. It is then taken in by plants. Plants further help neutralize nitrogen by taking it out of the soil and using it to manufacture leaves and shoots.

Inorganic Nitrogen

• Inorganic nitrogen enters soil through rainwater, chemical fertilizers and the atmosphere. If fertilizers are placed on the ground's surface, then nitrogen will be released back into the air. This process is called volatilization. Other processes through which nitrogen leaves the soil are leaching and denitrification. Denitrification occurs when some bacterial forms ingest inorganic nitrogen into a gaseous form and release it back into the atmosphere. Leaching occurs when excess nitrogen is washed deep within the soil and enters groundwater systems. This is a dangerous occurrence because excess nitrogen can infect fish and other aquatic life, causing fish kills and toxicity.

Considerations

• High-nitrogen soils have the potential to burn crops and disrupt soil structure. Nitrogen also encourages foliar growth at the expense of fruiting and flowering. If you have high nitrogen in your soil, neutralize it by refraining from adding nitrogen fertilizers. Amend soil with organic matter and mulch. Plant a cover crop of nitrogen-binding grasses and legumes. Once the crop is harvested the excess nitrogen will be taken with it.