Influence of no-till cover crop management on soil thermal properties

Soil thermal properties influence soil health parameters and can help determine crop productivity with changing global atmospheric climate. This study investigated the influence of no-till (NT) and cover crop (CC) management on soil thermal properties. The study site was managed with NT. The CCs used included hairy vetch (Vicia villosa Roth.), crimson clover (Trifolium incarnatum L.), winter wheat (Triticum aestivum L.), winter peas (Lathyrus hirsutus L.), oats (Avena sativa), triticale (Triticale hexaploide Lart.), barley (Hordeum vulgare L.) and flax (Linum usitatissimum L.). Soil samples were collected at 0–10, 10–20, and 20– 30 cm depths just prior to CCs being planted and also collected just before CCs were terminated. Treatments included NT CC and NT no cover crop (NC). Soil thermal properties (thermal conductivity [λ], volumetric heat capacity [CV], and thermal diffusivity [D]) were measured at 0, −33, and −100 kPa soil water pressures. CV at saturation was 13% higher under CC management compared with NC management. Averaged over all depths just before CC termination, λ and D at saturation were 21 and 35% higher, respectively, under NC management compared with CC management probably due to closer contact between soil particles. Results from this study suggest CCs with NT management may be able to resist extreme soil temperature changes which could improve soil health and crop productivity in these systems. NT and CC could improve crop productivity in the future but more in situ studies of soil thermal properties under these systems are needed.