Tillage Effects on Soil Thermal Properties

Abstract

AbstractTheoretical considerations indicate soil thermal properties may be altered by tillage, but few field studies have been conducted to compare soil thermal properties as affected by conservation or notill management systems. Surface‐soil thermal properties were determined in the row zone for three soils in three tillage systems: conventional till, chisel plow, and no‐till. The apparent thermal diffusivity was determined by harmonic analysis of soil temperature data, volumetric heat capacity from the volume fraction of the soil components, and thermal conductivity by the line source heat‐probe method. Soil volumetric heat capacity was similar for all tillage treatments. Thermal diffusivity was significantly greater in the notill system than in conventional and chisel plow tillage systems, indicating that thermal conductivity also was greater in the no‐till system. Direct determination of thermal conductivity by the line source heat‐probe method at one site indicated that thermal conductivity was more than 20% greater in no‐till than in the conventional till system. Percentage surface residue cover had a greater influence on soil temperature and soil heat flux than soil thermal properties.