EFFECTS OF AMMONIUM-STABILIZED N-FERTILIZERS ON YIELD AND QUALITY OF VEGETABLES

Cultivated plants normally take up nitrogen in the form of nitrate, so even when ammonium based fertilizers are applied, N has to be nitrified by bacteria before uptake can take place, however, this normally takes place within a few days.
The advantage of nitrate is its immediate availability, the disadvantage is its high vertical mobility.
The leaching of nitrate reduces N fertilizer efficiency and leads to nitrate accumulation in ground water.
Ammonium stabilizers inhibit the nitrification of ammonium for a certain time.
The new nitrification inhibitor dimethylpyrazole phosphate (DMPP, commercial name ENTEC) retards nitrification for 4 – 10 weeks according to environmental conditions.
In addition to reducing N losses by leaching, the addition of DMPP to ammonium based fertilizers leads to some ammonium uptake by the crop which results in lower nitrate contents and greener leaf colour.

Tests conducted in various European countries in the last few years have showed that DMPP containing fertilizers, when compared to conventional fertilizers in field-grown vegetables and fruit trees, reduced N leaching-loss and increased crop yield.
Even when the number of applications of DMPP containing fertilizer was reduced, crop yield was the same or higher than with standard application of conventional fertilizer.
Plants receiving DMPP-containing fertilizer were a darker green leaf colour and had a reduced nitrate content.

These effects can benefit the grower by maintaining an even supply of N to the crop, reducing the labour demand, and providing higher crop yields of better quality.

International Conference on Environmental Problems Associated with Nitrogen Fertilisation of Field Grown Vegetable Crops

R. Hähndel, W. Zerulla

nitrification inhibitor, DMPP, N leaching, N efficiency, NO₃ content

https://doi.org/10.17660/ActaHortic.2001.563.9