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Soil thermal properties can influence several soil processes important for crop productivity. This study was conducted to evaluate the influence of cover crops on selected soil physical and thermal properties. The field site was set up using a randomized complete block design with two levels of cover crops (cover crops versus no cover crops). The soil thermal properties measured included thermal conductivity, volumetric heat capacity, and thermal diffusivity. The physical properties of the soil studied included bulk density, volumetric water content, total pore spaces, water-filled pore spaces, air-filled pore spaces, gas diffusion coefficient, and soil pore tortuosity factor. Soil organic carbon was also measured. The results showed that soil organic carbon was 26% higher under cover crops management compared to no cover crops management. Thermal conductivity and thermal diffusivity were positively correlated with soil bulk density and these properties (soil thermal conductivity and soil thermal diffusivity) were higher under no cover crops management compared with cover crops management probably due to the proximity between soil particles. The volumetric heat capacity was positively correlated with soil organic carbon, with soil organic carbon being higher under cover crops management compared with no cover crops management. Results from the current study show that cover crops can improve soil physical and thermal properties which may benefit crop productivity as corroborated via laboratory measurements. [ABSTRACT FROM AUTHOR]

Soil thermal properties play an important role in crop productivity, but the influence of a multi-species cover crops (CCs) on these properties are not well understood. This study evaluated the effects of no-till CCs (winter wheat [ Triticum aestivum L.], crimson clover [ Trifolium incarnatum L.], triticale [ Triticale hexaploide Lart], hairy vetch [ Vicia villosa ], oats [ Avena sativa ], and cereal rye [ Secale cereale L.]) on soil physical (bulk density [BD], and volumetric water content [ϴ] at 0, −33, and −100 kPa soil water pressures) and thermal properties (thermal conductivity [λ], volumetric heat capacity [ C V ], and thermal diffusivity [ D ]). Soil samples were collected just before CC termination at 0–10, 10–20, and 20–30 cm depths from CC and no cover crop (NC) plots during 2021 and 2022. Results showed that, after 2 years, CCs reduced BD by 17% and increased ϴ at 0, − 33, and − 100 kPa soil water pressures by 23%, 25%, and 28%, respectively relative to NC management. Thus, λ under NC was 16%, 19%, and 20% higher at 0, − 33, and − 100 kPa soil water pressures, respectively, compared with CC management. Conversely, C V was 17%, 14%, and 15% higher under CC compared with NC management at 0, − 33, and − 100 kPa soil water pressures. Regression analysis further demonstrated that while plant root was the most important factor influencing λ at saturation, ϴ played the greatest role in λ at other soil water pressures. Expectedly, ϴ was the most important factor influencing C V at all measured soil water pressures. Conclusively, no-till CCs can improve laboratory measured soil thermal properties by moderating heat transfer. • CCs reduced BD and increased ϴ at measured soil water pressures relative to NC. • NC management significantly increased λ, while CC management improved C V. • At saturation, plant roots determined λ, while ϴ influenced λ at lower soil water pressures. • ϴ was the most important factor influencing C V at soil water pressures measured. • Multi-specie CCs can reduce extreme heat transport in a changing global climate. [ABSTRACT FROM AUTHOR]