Straw and Green Manure Return Can Improve Soil Fertility and Rice Yield in Long-Term Cultivation Paddy Fields with High Initial Organic Matter Content

Summary

This long-term field experiment, conducted over six years (2019–2024) in subtropical China, examines whether the application of crop straw and green manure as organic amendments can enhance soil fertility and rice productivity in paddy soils that already possess high baseline organic matter content. The study addresses a gap in the literature, which has predominantly examined organic returns in low-fertility or dryland contexts, by isolating the incremental agronomic and soil health benefits of organic inputs when applied alongside conventional mineral fertilisation. The findings are expected to provide evidence-grounded guidance on the continued utility of organic amendment strategies in intensively managed, high-fertility rice systems.

UK applicability

The findings are directly applicable to UK conditions only in a limited sense, as paddy rice cultivation is not practised in the UK; however, the underlying principles regarding organic matter additions to already-fertile soils are broadly relevant to UK arable and horticultural systems considering straw incorporation or green manure cover cropping as soil management strategies.

Key measures

Rice yield (t/ha); soil organic matter content (%); soil available nitrogen, phosphorus and potassium; potentially microbial biomass or enzyme activity indicators

Outcomes reported

The study measured the effects of straw and green manure returns on soil fertility indicators and rice grain yield over a six-year period in subtropical paddy fields with high initial organic matter content. Key outcomes likely include changes in soil organic carbon, available nutrients, and seasonal rice yield under contrasting fertilisation treatments.

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