Effects of different tillage systems on soil hydrothermal regimes in rain-fed field of Inner Mongolia

Soil hydrothermal regimes can be used for assessing the sustainability of agricultural ecosystems. The objective of this study was to determine the influence of five tillage practices ( no tillage low stubble ( NL),no tillage high stubble (NH),no tillage high stubble with residues (NHS),no tillage low stubble with residues (NLS) and conventional tillage (CT)) on soil temperature and soil moisture content in a degraded oat slope field under dry conditions. Samples taken were at soil depth of 0 80 cm and 0 100 cm layer in the Qing Shuihe county of Inner Mongolia for a period of 4 years. Data were analyzed by the Kriging interpolation method in the SUFER software. The results showed that:(1) There was a significant effect of no tillage with residue on soil temperature and soil temperature followed diurnal variation depending on the season although the magnitude decreased with soil depth. Maximum value of the surface soil layer (0 10 cm) was 17. 6 34. 0℃ ; the soil temperature was lowest at 06:00,the maximum value at 15:00; (2) During whole growth period,soil moisture content of NHS increased by 7. 37% ,NLS by 5. 93% compared to CT:At seeding stage,soil moisture content increased with soil depth up to a depth of 100 cm,at the tillering stage,it was low in 0 20 cm,at flowering stage it was low in 0 40 cm depth,followed by a gradual increase up to 100 cm depth. The moisture content also was affected by season and with the rainfall. (3) Thermal capacity increased as soil organic matter increased and the NHS had a buffering effect on the soil temperature. ( 4 ) In rain-fed areas of the Yellow River basin this study will help the farmland management.