Llyn Rhys

Exploring the potential of digestate as an agricultural fertiliser

Project aims:

Given the pressure to increase yields to feed a rapidly-expanding population, our soils are going to be under ever-increasing demands to perform consistently year in, year out. Fertiliser replacement products such as digestate, a bi-product from Anaerobic Digesters (AD), may be able to provide a suitable alternative to compound fertiliser. This alternative may also help to address the commercial and environmental requirements by offering low environmental impact, with effective and sustainable solutions by nutrient cycling.

The number of AD plants are on the increase, therefore farmers are being offered digestate at competitive prices of between £5-7.00 per tonne, although this is dependent on location and distance from the AD plant. This project aims to further inform farmers of the potential use of digestate as a bio-fertiliser and an alternative to artificial fertiliser, as well as best practice to promote grass growth and minimise environmental impact.

The project will evaluate the benefits of using anaerobic digestate compared to compound fertiliser, and compare the efficiency and effectiveness of 3 different application rates for the digestate. Grass growth will be measured for each application rate, as well as on a control and artificial fertiliser plot for comparison in productivity. Fresh grass samples will also be taken during the duration of the project, and soils will be tested following the trial.

We hope this project will also provide an opportunity to raise the awareness and understanding of soil fertility, so that farmers consider options of how to improving soil performance in sustainable ways, such as using environmentally-friendly materials to enhance the nutrient profile and conditioning of soils.

The Potential for Balansa Clover in Wales

Project aims:

• A viability study into the suitability of Balansa clover to Welsh climate and conditions for forage and grazing compared to other forage crops.
• FIXatioN Balansa clover is an annual legume that can tolerate a variety of soils and is capable of producing large amounts of biomass. Its rosette growth patterns allow it to be persistent for intensive grazing or cutting. Balansa clover is also resilient to cold and dry conditions. In terms of feed value, Balansa clover can produce up to 5,882 kg/ha DM and 28% crude protein on a dry matter basis.
• The project will also evaluate the potential of using diverse seed mixes as biological soil aerators in grass-based livestock systems in Wales. This method can improve soil structure and fertility where soil degradation is becoming an ever-increasing problem.
• The biological aerator seed mix contains spring oats, Daikon Raddish, Crimson Clover, Winter Vetch, white mustard, buckwheat, Phacelia, Italian ryegrass, Balansa clover and Frosty Berseem Clover, which all have varied root structures. The project will evaluate how well the species and mix perform in Wales.