REGULAR ARTICLE Temporal processes of soil water status in a sugarcane field under residue management G. O. Awe & J. M. Reichert & L. C. Timm & O. O. Wendroth Received: 1 August 2014 /Accepted: 12 October 2014 /Published online: 25 October 2014 # Springer International Publishing Switzerland 2014 Abstract Background and aims The knowledge of soil water storage is vital for rational agricultural management, and in soil-plant-water relations. This study was con- ducted 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. Methods Soil water storage (SWS) and matric potential (Ψ) 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. Results 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 combina- tions of log (Ψ), ET and P gave satisfactory results, however state-time analysis was better with higher R 2 values and incorporated errors. Conclusions 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. Keywords Soil water storage . Soil-atmospheric variables . Residue management . Classical regression . State-time analysis Introduction Among the soil properties, soil water storage is the most important state variable in hydrologic and biological processes (Choi and Jacobs 2007). In the superficial layer, soil moisture plays a significant role in water dynamics and energy flow (Vereecken et al. 2007). It controls the partitioning of precipitation (Pachepsky et al. 2003) into infiltration, surface runoff and deep percolation, which are important components of the soil water balance. Soil moisture is very important in crop production. Of the four physical conditions (water, tem- perature, aeration and mechanical resistance) directly related to plant growth, water is the dominant control- ling factor as others are affected by water content (Letey Plant Soil (2015) 387:395–411 DOI 10.1007/s11104-014-2304-5 Responsible Editor: John McPherson Cheeseman. G. O. Awe (*) : J. M. Reichert Department of Soil Science, Center for Rural Sciences, Federal University of Santa Maria (UFSM), Av. Roraima 1000, 97105-900 Santa Maria, RS, Brazil e-mail: gabrielolaawe@yahoo.com L. C. Timm Department of Rural Engineering, Federal University of Pelotas (UFPel), C.P. 354, 96001-970 Pelotas, RS, Brazil O. O. Wendroth Department of Plant and Soil Sciences, University of Kentucky, Agricultural Science Center, 1100 South Limestone St., Lexington, KY 40546-0091, USA