Crop productivity has been decreasing continuously in the northeast of Thailand due to impacts of microclimate and some soil properties conditions. Two experiments were trials in the farmer’s fields at Wang-wa (L1) and Phea-fan (L2) villages, which are located in rain-fed upper paddies of Khon Kaen province. This study aims to investigate effects of tied ridging and surface mulching on soil moisture and soil temperatures in the cassava fields. The field monitoring system (FMS) has been run to monitor and record the climatic data, soil moisture and soil temperatures. Tied ridging and surface mulching by rice straws were designed as a soil management. The results indicated flat cultivation provided soil moisture higher than tied ridges in these present experiments. While ridging provided higher soil temperatures compared to flat soil cultivation. Mulching is benefit on soil moisture in contrast it produced higher soil temperatures than flat cultivation. For cassava grown under rain-fed condition, soil moisture and suitable soil temperature are important. In the study areas showed changes in soil moisture and soil temperature are highly relatives to rainfall and air temperature in ridging and mulching treatments rather than flat soil and non-mulching. Hence, the management practices should be adopted considering to microclimate and soil property conditions.