Effects of a straw layer over bare soil on surface and soil variables in Southern Brazil

Resumo

Changes in land use can have significant impacts on physical processes that act between the surface and atmosphere. Crop residues deposited on the soil surface can affect soil response to environmental variables. In this work, we analyze the effects of straw layers (SL) bare soil (BS) soil on surface and soil variables in a subtropical climate region in southern Brazil. We analyze measured data of surface temperatures, soil temperatures, soil volumetric water content and soil heat flux from May to November 2015, , with straw layer replaced three time. The presence of a straw layer increase soil volumetric water content (VWC) by 5% to 15%, decrease the surface and soil temperatures and the soil heat flux, besides present a lower thermal amplitude than bare soil. The soil and surface temperature are more sensitive to VWC variations in bare soil. These results can be applied in land surface and agricultural models to better represent the thermal soil behavior.