ABSTRACT

Soil thermal properties play many major roles in a soil as they influence the soil temperature and define the soil microclimate, which regulates many soil health parameters as well as life cycles of soil biota. Although cover crops (CC) can affect soil thermal properties, they are one of the least studied areas. This study compared the effects of CC on soil thermal properties in a corn (Zea mays L.) cropping system at the Elsberry Plant Material Center–USDA in Missouri (USA). The study design consisted of (a) no-till CC (NC), (b) conventional till no CC (CN), (c) no-till no CC (NN), and (d) grass (G) treatments. The first CC establishment in the NC treatment was done in October 2019. Soil cores were collected in April 2021 from 0-to-40-cm depth at 10-cm increments (96 samples) and analyzed for volumetric heat capacity (Cv), soil thermal conductivity (λ), soil thermal diffusivity (α), soil organic carbon (SOC), bulk density (BD), and volumetric water content (θ). As per the results, NC did not significantly improve SOC, BD, or soil thermal properties, because the biomass accumulation by CC was not enough due to the lack of CC establishment duration. The G treatment showed significantly higher Cv and lower λ in several soil depths. The study outcomes suggested that long-term maintenance of CC with cropping systems are needed in quantifying the effects of CC on soil thermal properties.

AUTHORS:
Sidath Subodha Mendis
Ranjith Udawatta
Stephen H. Anderson
Jamshid Ansari