KindHarvest summary: Research coordinated by Rothamsted Research found that crop diversity, legumes and organic amendments can help maintain high yields while reducing synthetic-fertiliser use. The evidence came from more than 30 long-running field experiments in Europe and Africa.
What the trials showed
Rotations containing nitrogen-fixing crops such as beans and clover improved soil fertility. A wider range of crops helped suppress weeds and diseases, while manure, compost and plant residues added nutrients and organic matter.
Across the trials, manure generally had a stronger yield effect than compost or plant cuttings. High synthetic-fertiliser treatments did not automatically outperform systems that combined ecological practices with lower input rates.
Why it matters
Lead author Chloe MacLaren described the approach as ecological intensification: strengthening natural processes while using external inputs more efficiently. Lower fertiliser dependence could reduce exposure to price shocks as well as nutrient losses to water and greenhouse-gas emissions.
Limits and farm application
The study supports a direction rather than a universal replacement rate. Nutrient supply from manure and legumes varies, and reducing fertiliser without measuring crop demand, soil reserves and nutrient removal can create deficiencies. Local trials and multi-year budgets remain essential.
Related KindHarvest reading
KindHarvest has a companion brief covering the same research through another news report. Read āStudy: Less is more when it comes to chemical fertilizerā.
Source and credit
This KindHarvest Team research brief is based on reporting by Jonathan Riley for Farmers Weekly, published 27 June 2022. Read the Farmers Weekly report or view the peer-reviewed study in Nature Sustainability.