Nitrogen – Why We Need to Stop and Consider!
There is currently a massive push towards an increase in awareness as to nitrogen efficiency and the problems it can cause.
Agriculture’s Contribution to Greenhouse Gas Emissions
Looking at climate change, agriculture produces around 9% of the UK’s green house gas emissions with the emissions from Methane, Nitrous Oxide, Ammonia and Carbon Dioxide.
The Problem of Nitrogen Loss in Agriculture
The efficiency of some of the nitrogen applications we have seen and it’s getting worse in some places is a 60-80% loss of applied nitrogen. This is through the lack of consideration and knowledge on how, when and why people are applying nitrogen to crops.
Denitrification and Global Warming
Denitrification is the biggest contributor to Global Warming from soils which we can easily reduce by good practice.
Understanding and Reducing Denitrification
Denitrification which is the conversion on nitrate to nitrite to nitrogen gas and Nitrous oxide, happens from conditions when soils are in wet, anaerobic states. The process is accelerated when >60% of the soils pores are filled with water and improved drainage can help greatly. Aerobic bacteria in the soil need to breathe and get oxygen from somewhere. So if in compacted or waterlogged conditions they will begin to convert nitrate into a form which they can release the oxygen, leading to a huge loss of nitrogen as gasses. Consider soil drainage, soil texture and climate, ensure a good soil structure and avoid areas of compaction and waterlogging, improve proportion of nitrogen taken up by the plant (ensure good crop rooting for best uptake), match Nitrogen applications with requirements (split doses) and time applications for crop uptake.
Other Nitrogen-Related Emissions: Urea and Ammonia
In the process of Urea breakdown it also releases the green house gas CO2 that was added into the product during manufacturing. There is also risk of ammonia loss which is greatest in warm, dry soil with a high pH and least in moist, cool soils. Ammonia is also released from manure applications and spreading equipment makes a big difference.
Reducing Ammonia Emissions Through Good Practice
We can reduce the ammonia emissions simply by good practice by incorporating organic manures and slurry within 12 hours, use injection, trailing shoe or trailing hose equipment for slurry or digestate, cover slurry stores, apply Urea in the right conditions, use an inhibited Urea with a source of carbon such as Humates, use cover crops and enhance soil organic matter levels.
The Impact of High Nitrogen on Plant Health and Yield
High levels of nitrogen to the plant create plant stress and imbalance. Following this we see nutrient deficiencies, pest attack and disease. Apply the nitrogen according to yield potential. Yield potential compared to previous years is down. Where we would usually see a 10-12 tonne crop of wheat, in a lot of areas we are only seeing 8-9 tonne crops or less. This is where there is very minimal roots on plants, only 2-3 leaves and no tillers. Without first establishing the crop properly to take up nitrogen applications (certainly large doses), we might as well pour the nitrogen down the drain instead for all the good it will do and the money it would save us on applying it.
The Role of Humates and Fulvic Acid in Nitrogen Management
All nitrogen should be applied with a Humate and Fulvic acid this next month. This will help to chelate and sequester the nitrogen in the soil and hold it in the root zones until it is taken up, reducing drastically the levels of nitrogen lost by volatilization or leaching.
