Effects of soil tillage and mulching on thermal performance of a Luvisol topsoil layer

Abstract

Important heat transfer processes occurring on soil surface control the thermal environment within the topsoil layer and the boundary layer above. Soil management practices such as the application of mulches or the formation of a soil micro relief through tillage modify the thermal regime of soils. The aim of this study was to compare the effects of soil tillage and the application of stubble mulch and different amounts of straw mulch on the thermal behaviour of a Luvisol. The experiments were performed from January to May 2007, in a field sown with winter wheat. Temperature was measured with copper-constantan thermocouples placed over straw and over stubble, at soil surface and at 2, 4 and 8 cm depths. Compared with tilled bare soil, the application of straw mulch seems to affect the soil thermal regime more significantly than that of stubble mulch. The topsoil under straw mulch showed the lowest thermal amplitudes and the highest minimum temperatures. From March to May, the mean temperatures in the profiles covered by straw were significantly lower than those recorded on the remaining plots. Implications of these techniques for soil temperature control in crop growing are discussed too.