The 2025 Brian Chambers award

Information about the winners in 2025

The 2025 award attracted another selection of varied and high quality entries. Unusually, the judges decided to award four prizes, as there was a tied score between two of the finalists. 

The judges concluded that the poster presentation that justified winning the first prize of £1,000 was by Lillian Hearn, studying at Melbourne University, Australia. Her research examined the effects of oxygen scarcity and also the legacy effects of crop rotations on nitrogen turnover dynamics, particularly denitrification. This is particularly important in the heavy clay soils common in Victoria. 

Her key findings were that partial anaerobic conditions resulted in denitrification losses dominated by N2O, whereas under fully anaerobic conditions (90% water-filled pore space), denitrification was dominated by full reduction to N2. In addition, increasing dissolved organic carbon (DOC) levels in the soil also showed a positive relationship with N consumption (denitrification + immobilisation).

Lillian’s webinar presentation can be seen by clicking the button below. 

First 2025 runner-up, David Clarke of NIAB/ Cranfield University, in the UK, presented his research on crop simulation modeling for on-farm N
management. Crop N use efficiency (NUE) in the UK is about 55-70%, whereas the optimum is considered to be 90%. Whilst using crop canopy sensors can help to increase NUE, they cannot determine whether variability in soils is a cause.  David’s work used an existing crop model, SIRIUS, initially evaluating the model to see if it could explain sub-field variation in yield and N uptake across soil, weather, and N-rate differences. Testing the model on a long-term experiment site showed good results, with grain yield, protein, and grain N uptake across
soil types, N rates, and years being accurately reproduced, indicating sufficient model performance to support sub-field N management on farm. 

The model is now being evaluated in on-farm trials, and shows potential to reduce N use as well as increasing N recovery, alongside increasing the financial margin and reducing N-related greenhouse gas emissions. 

David’s presentation for the webinar can be seen by clicking the button below. 

One joint runner-up was Bright Laboan, of Cranfield University, in the UK. His research examines the potential for development and use of site-specific organo-mineral fertiliser (OMF) for sustainable cocoa nutrition in West Africa. Soils in the West African cocoa belt  are characterised by: low pH, high Al and Fe, resulting in P fixation, and reducing the availability of conventional fertiliser P for cocoa plant
uptake. Cocoa bean yield in the region is low, affecting both global cocoa demand and farmers’ livelihood. By using OMFs, it was expected that the carboxylic groups of the organic compounds would chelate the AL and Fe, also increasing pH, cation exchange capacity and soil organic carbon. As a result P availability to the crop should improve, increasing yield and therefore income.   

An OMF made of composted cocoa bean husk and poultry manure, with a small amount of NPK mineral fertiliser was evaluated. The OMF resulted in an increase in yield of 130-209%, compared to a mineral NPK fertiliser alone, also improving yield when compared to compost use alone. Importantly, the OMF also gave a large residual effect, with yield in the second year of cropping being significantly larger than those from a crop with NPK fertiliser. his enhances the economic benefit to farmers. Trials are continuing to evaluate whether this effect lasts for more than one additional season.   

Bright’s presentation for the webinar can be seen by clicking the button below. 

The remaining joint runner-up was Wilfred Adjadeh, of Aarhus University in Denmark. His work seeks to optimise N fertiliser use through balancing the trade-off between  crop yield and nitrate leaching. 

There is limited work evaluating the yield-leaching trade-off. As N use, and therefore yield, increases, the rate of leaching loss also increases, so called marginal leaching. These losses differ by soil type, crop sequence, N rates, and legacy N. Using multi-year farm trials, the effects were quantified on 5 main crops: winter wheat, spring barley, maize, triticale and sugar beet.

The highest losses occurred in year 3 of winter wheat on a clay soil, probably driven by legacy N build-up, whilst the second highest loss was from a maize crop on a sandy soil. N leaching increased with increasing N rate, with greater increases at higher N rates.  A clear yield-leaching trade-off was demonstrated, which must be used to guide N use decisions. 

Wilfred’s presentation is not available at the moment, due to publication reasons.