Nutrien Ag Solutions investing in nitrogen use efficiency trials for cotton growers

Ongoing trials lead by Nutrien Ag Solutions are investigating ways that cotton growers can increase the amount of cotton lint grown per kilogram of applied nitrogen.

Nitrogen is one of the biggest inputs for cotton growers, but it is also often lost from the cropping system in high quantities, particularly in high soil clays and flood furrow irrigation systems.

Nutrien Ag Solutions Technical Services Manager Bill Adams said recent research had shown almost half of the applied nitrogen to irrigated cotton systems was lost.

“We see significant losses caused by denitrification in cotton fields, so we are conducting collaborative research with Jon Baird (New South Wales Department of Primary Industries and CottonInfo), to help understand and manage these losses, in order to improve nitrogen use efficiency of applied fertiliser,” said Bill.

“One of the strategies to manage denitrification losses is to use a nitrification inhibitor and/or a polymer coated urea. Our trials are testing lower rates of applied nitrogen with two different treatment options – a polymer coated urea and nitrification inhibitor treated urea blend; and a straight nitrification inhibitor treated urea.”

These treatments are compared against the standard rates of applied nitrogen to gain a deeper understanding of the fate of nitrogen in commercial fields by conducting in season comprehensive soil and plant analysis.

“Analysing these key nitrogen indicators will provide added insights into the fate of the applied fertiliser and how products like nitrification inhibitors and polymer coats can influence this,” said Bill.

“The trials are measuring plant and soil nitrogen throughout the crop, pre plant in-crop and after maturity to measure the impact of supply both on the current crop and the organic nitrogen supply available for the next season.”

Nitrification inhibitors aim to preserve nitrogen in the stable ammonium form, reducing the risk of losses from denitrification and off field movement. It does this by impacting the microbial process of nitrification. These trials compared the following nitrogen inhibitors, across multiple irrigated cotton sites on the Darling Downs and Namoi Valley:

  • DMP-G, commercially available as eNpower® from Incitec Pivot Fertilisers. DMP-G works by inhibiting nitrifying bacteria in the soil, slowing down the conversion of ammonium N to nitrate which is more prone to loss.
  • Nutrien’s ESN® is a polymer coated granule designed to protect the nitrogen and depending on temperature allow it to release over 50 – 90 days. By slowing the release the theory is we can more closely synchronize the supply of nitrate to the crop demand, thereby reducing the amount of nitrate in the soil and reducing the denitrification risk.

Nutrien Ag Solutions will be performing more cotton nitrogen use efficiency trials next cotton season with CenturoTM, a new nitrification from Koch Agronomic Services which contains the active Pronitiridine and can be applied to urea, anhydrous ammonia, or any other liquid nitrogen products.

Dan Skerman, Nutrien Ag Solutions Agronomist and cotton grower at Skerrman Farming on the Dalring Downs said he is very interested to understand how to increase the amount of cotton lint grown while using less applied nitrogen.

“These types of initiatives provide growers with more confidence in using new technology like nitrification inhibitors. At the end of the season when we analyse the data from our plant and soil samples, we will be able to get a good indication of how the different treatments have performed under different conditions,” he said.

For more information on these trials, contact: Bill Adams, Plant Nutrition Technical Services Manager, Nutrien Ag Solutions