The What, How And Why Of Nitrite Poisoning

Although the atmosphere is made up of 79% nitrogen (N2), living organisms cannot utilise this form of nitrogen due to the inactive property of the gas. Nitrogen-fixing bacteria in the soil convert nitrogen into ammonia, which in turn is converted to nitrite and then nitrate by the same bacteria.

- Dr Ockert Einkamerer

Nitrate is an essential nutrient for plants as it is used as a precursor for protein synthesis. Plant enzymes convert the nitrate commonly found in growing plants back to ammonia, which then drives the process of protein synthesis.

During the production of green grazing and its fertilisation, the nitrogen and nitrate content increases. Nitrate forms under normal growth conditions, but because it is converted into plant protein, excessive accumulation does not occur in plants.

Causes of increased nitrate

However, any conditions that impede the growth of the plant can lead to accumulation. This includes stress factors such as cloudy or cooler weather as well as reduced water supply. Hot, humid weather and hot winds result in the same reaction. Hail, frost, and herbicides can also hinder photosynthesis and raise nitrate levels in the plant.

After periods of water stress and drought that is followed by rain or irrigation, the plant accelerates its uptake of nitrate from the soil, which tends to overwhelm the conversion thereof to proteins. This results in raised nitrate levels in the plant. When normal growth conditions return, nitrate is converted to protein at an accelerated rate; this may take weeks to normalize.

Soil remains the primary source of nitrate in plants and fertilisers, and urine and manure from animals can cause nitrate to accumulate in the soil.