KindHarvest summary: A study drawing on long-running field experiments found that farms can sometimes use less chemical fertiliser while maintaining yields when they combine inputs with practices such as diverse crop rotations, manure and compost.
What the study examined
The researchers analysed 30 long-term experimental plots in Europe and Africa. Study lead Chloe MacLaren described the approach as ecological intensification: using ecological processes alongside carefully targeted inputs rather than relying on fertiliser alone.
Across the experiments, practices that improved nutrient cycling and soil function reduced the amount of chemical fertiliser needed to sustain production. The findings offer evidence that yield and lower input use do not always have to move in opposite directions.
Limits and practical context
None of the experimental sites was in the United States, and researchers interviewed for the report cautioned that large Midwestern farms face different soils, climates, labour needs and financial pressures. Cover crops and longer rotations can also carry short-term costs or risks.
The practical lesson is to test combinations locally, measure yield and profit over several seasons, and treat fertiliser reduction as a managed transition rather than a fixed prescription.
Source and credit
This KindHarvest Team research brief is based on reporting by Dana Cronin for Harvest Public Media and KOSU, published 9 August 2022. Read the original KOSU article.