Making the most of Nitrogen

Reducing nitrogen loss in grassland

A group of 15 dairy farmers are getting a new field lab underway, looking at maximising the efficient absorption of nitrogen-based fertilizers. The Exe Vale Farmers are comparing fertilizer formulations and their effect on grass yield.

Five of the group members will be hosting trials on their own farms, meaning the results are replicated across different sites and soil types. Each plot is divided into four buffered sections. Three of the sections will have different formulations of a nitrogen-based fertilizer (ammonium nitrate, urea, urea with urease inhibitor) and the fourth as a control plot with no additives. Different levels of fertilizer are being applied each month and plate meter grass measurements will monitored throughout grazing.

Urea inhibitors are fairly new and were particularly interesting to the group as they had not used them before. They have the potential to be really interesting in reducing the amount of nitrogen via ammonia loss by blocking urea converting to ammonia gas, which evaporates into the atmosphere. By slowing this down, the ammonium has more time to penetrate into the soil so that the nitrogen can be taken up by the plant. 

The project is coordinated by Briony Burge of Creedy Associates who helped the farmers get funding for the study and plays a pivotal role in running the group. The Exe Vale Farmers hope to discover the fertilizer type and application levels that maximize fertilizer efficiency. The goal is to decrease artificial fertilizer use without sacrificing yield, reducing their costs and their environmental footprint. With approximately 95% of farmers using fertilisers the pilot has great potential. 

Find out more about the field lab here >

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