Cover cropsMixtureConventional + organicGrass + legumeBiomassNitrogen accumulation
What the research measured
A 2018 meta-analysis reported greater mixture biomass than either species alone on average. Relative responses varied with soil, preceding crop, growing degree days, and the share of vetch in the seed mix.
21 US studies · 55 site-years · Thapa et al., Agronomy Journal (2018).1 independent source.What it is. A grass–legume mixture studied across different seeding proportions and growing conditions. Findings do not describe a particular commercial blend.
Study conditions and limitations
- Each bar uses a different monoculture baseline. These are relative biomass responses, not yields, nitrogen credits, or a comparison of brands.
- Pooled results do not predict the response to a specific mixture at an individual farm. No uncertainty interval is reproduced here.
- Confirm species proportions, termination requirements, and organic seed status for the actual blend.
Read the sources · 1
- Biomass production and nitrogen accumulation by hairy vetch/cereal rye mixtures: A meta-analysis ↗
Pooled mixture biomass was 63% greater than hairy vetch alone and 21% greater than cereal rye alone. Study conditions affected the relative response.
Before you buy, ask
- What seeding rate, date, and termination timing did the cited studies use?
- How does termination timing before my cash crop change the nitrogen and moisture picture?
- Which species or mixture fits my rotation window and equipment?
Record
- Sources checked
- September 26, 2026. Every figure shown is printed on the linked page; unit conversions are noted on the chart.
- Company response
- None yet. Makers and suppliers of this product can send corrections, additional trials, or a statement; it is published here, labelled, and never edits the research summary. Send a correction →