Soil tillage systems to reduce the harmful effect of extreme weather and hydrological situations

Soil as the largest potential natural water reservoir in the Carpathian Basin has increasing importance under conditions of predicted climate change resulting in increase of probability of extreme hydrological events. Soil management changes soil structure and has a major effect on soil water, heat and nutrition regimes. In this study the effect of four tillage treatments in combination with catch crop management was studied on soil hydraulic properties and water regime under semi-arid conditions. Investigations were carried out in a long-term soil tillage experiment established on Calcic Chernozem soil in Hungary. Tillage variants comprised mouldboard ploughing, disking, loosening combined with disking and direct drilling. The crop sequence between September 2003 and September 2004 comprised maize (main crop), rye (catch crop) and pea (forage). In May 2004, disturbed samples and undisturbed soil cores were collected from each tillage treatment/catch crop combination. The main soil physical and hydrophysical properties were determined in laboratory. In each treatment, capacitive soil moisture probes were installed up to 80 cm depth to ensure continuous measurement of soil water content. Total soil water amounts of chosen soil layers and soil water content dynamics as a function of depth were evaluated for selected periods in order to quantify the effect of the studied management systems on soil water regime. The main conclusion from the experiment is that under such (or similar) ecological conditions, the uniform, „over-standardized“ adaptation of tillage methods for soil moisture conservation is rather risky, their application needs special care and the future is for site-specific precision technologies. These are, in combination with catch crop application can be efficient measures of environmental protection and soil structure and water conservation.