Temporal processes of soil water status in a sugarcane field under residue management

The knowledge of soil water storage is vital for rational agricultural management, and in soil-plant-water relations. This study was conducted to evaluate the temporal processes of soil water status of a sugarcane field under residue management during the 2011/2012 and 2012/2013 growing seasons in southern Brazil. Soil water storage (SWS) and matric potential (I) were monitored in the 0-10 and 10-20 and 40-60 cm layers using time domain reflectometer sensors and tensiometers while precipitation (P) and potential crop evapotranspiration (ET) were obtained using rainguage and daily weather data. There was significant temporal variation of soil water status with soil depths. SWS was lower while matric potential was higher in no mulch treatment than in mulched treatment in both growing seasons. SWS cross-correlated with other variables, however, results were not the same for the different soil depths and treatments. Classical regression of SWS from combinations of log (I), ET and P gave satisfactory results, however state-time analysis was better with higher R-2 values and incorporated errors. State-time analysis, combined with state-space could be a useful tool for good predictions of soil water status. Residue mulching influenced soil water status, thus proved to be a sustainable soil management practice.