Pulse Brain · Growing Health Evidence Index
Tier 3 — Observational / field trialPeer-reviewed

Effects of cover crops on soil aggregate‐associated organic carbon and nitrogen characteristics in a cotton–corn rotation system

Wei Dai, Gary Feng, Ardeshir Adeli, John P. Brooks, Johnie N. Jenkins, Xi Zhang

Soil Science Society of America Journal · 2025

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Summary

This three-year field study evaluated winter cover crop treatments—including elbon rye, daikon radish, Austrian winter field peas, and mixed species planted sequentially—on soil health in a no-till dryland cotton–corn rotation. Whilst aggregate size distribution did not differ significantly among treatments, sequential planting of mixed cover crops and pea monoculture enhanced SOC and TN stocks overall, with greatest benefits concentrated in fine aggregates (<0.25 mm), suggesting that strategic cover crop selection can improve soil carbon sequestration and nitrogen retention in dryland systems.

UK applicability

The findings may have limited direct application to UK farming, as the study was conducted under dryland conditions in a cotton-corn rotation system not typical of British agriculture. However, the mechanistic insights regarding cover crop species effects on soil organic matter accumulation and aggregate-bound nutrient storage could inform cover crop selection strategies in UK arable and mixed farming systems, particularly in drier regions or under climate change scenarios.

Key measures

Soil organic carbon (SOC) stock (Mg ha⁻¹), total nitrogen (TN) stock (Mg ha⁻¹), aggregate size distribution (mm fractions), aggregate stability, C and N preservation capacity by aggregate fraction, proportion of SOC and TN within specific aggregate size classes

Outcomes reported

The study measured topsoil aggregate size distribution, stability, and the stocks of soil organic carbon and total nitrogen in bulk soil and aggregate fractions under different winter cover crop treatments over three years. It assessed how cover crop species and sequential planting strategies influence the spatial distribution and preservation of carbon and nitrogen across soil aggregate sizes.

Theme
Farming systems, soils & land use
Subject
Soil carbon & organic matter
Study type
Research
Study design
Field trial
Source type
Peer-reviewed study
Status
Published
Geography
United States
System type
Mixed farming
DOI
10.1002/saj2.70137
Catalogue ID
SNmov0ffjn-14ijya

Topic tags

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