NUE trials of biostimulants continue to show results

Nutrient use efficiency (NUE) is the phrase on everyone’s lips this season. Whilst fertiliser prices have come down from last year’s high, many growers bought nitrogen at over £700/t last autumn and so need to recoup some of that cost by improving nutrient use efficiency in their crops.

Nutrient use efficiency is the ability of crops to take up and utilise nutrients and growers need to aim for at least 70% NUE to deliver a solid return on investment for those expensive inputs. There are a number of factors that influence NUE, starting with soil health. At a pH of nearly neutral, 100% of applied NPKs will be available to the crop, so soil analysis is advisable to see if soil conditioning is required. Other factors include fertiliser choice, application timing and spreader calibration.

More recently, it has been recognised that biostimulants can also help improve NUE. Trials of IntraCrop’s Nutrino Pro foliar nitrogen with biostimulants at Newcastle University in 2022 demonstrated that yield and quality can be maintained under a reduced nitrogen regime. The trial investigated the effect of Nutrino Pro applied either alone or as part of a Yieldbuilder biostimulant sequence on plant growth and yield, when applied with 100% and 85% of the recommended nitrogen rate. A zero N control was also included to provide an accurate baseline of the fertiliser response.

Normalised Difference Vegetative Index (NDVI) is a measure of the amount and vigour of crops and can be directly related to leaf area index (LAI), biomass and photosynthetic capacity. Reducing the nitrogen from 100% to 85% reduced the NDVI from 0.845 to 0.83. Nutrino Pro applied at BBCH39 increased the NDVI to 0.853, with the highest recorded where Nutrino Pro was applied as part of a Yieldbuilder sequence.

The reduced biomass translated into lower yields. Decreasing the nitrogen rate from 100% to 85% (=21 kg/ha) of the recommended dose reduced yield by 1.55 t/ha (11.85 to 10.3 t/ha). A single application of Nutrino Pro 20 l/ha at BBCH39 increased yield by an impressive 0.84 t/ha and reduced carbon impact (t/CO2e/ha) by 8%. Using Yieldbuilder, a combination of recommended biostimulants applied in sequence, most notably outperformed the 100% nitrogen rate, with a 12.1 t/ha yield, giving a greater return on investment as well as an environmental impact reduction.

For 2023, IntraCrop is focusing on further NUE trials to determine the most appropriate timing for biostimulant applications. Partnering with research institutes, the field trials will measure results for biostimulant applications, alone or in sequence and how well they perform under different rates of nitrogen. Intracrop is conducting trials on winter wheat, OSR, spring oats & spring barley across the UK to help give clear agronomic advice on the use of biostimulants to improve NUE.

27th June 2023