Money tap must open further for research into ammonium-based plant nutrition

Wild rye roots release potent nitrification inhibitors. Plant breeders have transferred the chromosome segment carrying the responsible genes to hexaploid wheat varieties. Scientists have high expectations of the suppression of nitrifying microbes in the rhizosphere by root-released nitrification inhibitors as it is expected to improve nitrogen use efficiency and boost crop yields. Research into this phenomenon is in full swing in wheat, sorghum, maize and rice.

A temporarily increased ammonium level in the soil is not new. It occurs, for example, after spreading nitrogen fertilisers to which a urease and/or nitrification inhibitor has been added. This is mainly about saving nitrogen, not about increasing crop yields per se. However, for some scientists is boosting crop yields with ammonium-based plant nutrition a target itself. Given the rapidly growing world population, the increasing problems with nitrogen pollution and the already observable climate change, the proposal of a higher share of ammonium in the nitrogen nutrition deserves a fair chance. This includes generous research financing, because there are still many open questions that cry out for an answer.

Indeed, there is a lot of work to be done. The agricultural pros and cons of ammonium-based fertilisation need to be further examined, including possible effects on pests and diseases. Also, the ecological footprint of ammonium-, nitrate- and ammonium nitrate-based fertilisation deserves attention. A comparison with the world’s most widely used fertiliser urea should not be forgotten. The possibility of differences in response to ammonium between crops (and between varieties!) should be considered when designing experiments. And so there are many other aspects to consider. This requires generous research funding. It is up to governments to come up with money for this research. Since society as a whole will benefit from a more economical nitrogen use and reduction of nitrogen losses, financing from public funds is more than desirable. And if ammonium-based fertilisation is good for people and the environment, but not for farmer’s income, then financial compensation is appropriate.

More information about ammonium-based plant nutrition and biological nitrification inhibition in the Plant nutrition courier magazine 2021-05 issue.