• Isik Ozturk

Here today, gone tomorrow: Saving wheat from climate change

Over the last century, the modern agriculture has changed the global nitrogen cycle dramatically as a consequence of intensification. This poses severe challenges that currently defy solutions. First off, the value of our cultivated plant material as food that relies on nitrate as their primary source of nitrogen is diminishing. Second off, the detrimental effect on the environment causes nitrate leaching to water bodies resulting in harmful algal blooms; ammonia volatilization, causing eutrophication and reductions in plant biodiversity; and nitrous oxide emissions, contributing to global warming and ozone depletion.

An estimated 45% of the nitrogen applied to mono-cultured C3 cereal plants is converted to plant biomass. This is a low nitrogen use efficiency. Science indicates that optimum N fertilizer application rate for the wheat is about 105 kg nitrogen per ha, which is much below the threshold value of 170 kg per year as defined by most EU countries. So, we are already giving too much nitrate to the crops that is not being used, and it is detrimental to the environment. In addition, we live in a world where the concentration of the carbon-dioxide in its atmosphere is rising at an increasing rate. The researchers observe that carbon-dioxide directly inhibits the assimilation of nitrate into organic N compounds in C3 plants.

So what to do? New fertilization methods/technologies are to be explored. The use of nitrification inhibitors for ammonium fertilization in C3 plants is being studied to remedy the current nitrogen cycling problem in intensive agriculture. The studies identify how nitrification inhibitors affect crop growth and grain N content with ammoniacal N fertilization at elevated carbon-dioxide levels.

The lab studies do indicate increased N use efficiency. The field trials with FACE (Free-Air Carbon Enrichment) technology are under way.

#ammonia #fertilization #climatechange