Can Long-Term Crop Rotation Improve Soil Hydro-Physical Quality and Production Under No-Tillage.

Adoption of new conservation practices generally demonstrate short-term or transient and long-term or relatively stable impact on soil and environmental quality and yield production. The long-term interactive effect of cropping system and tillage management on soil physical quality and its relation with crop yield is largely unknown. We hypothesized that diverse cropping system may increase the no-tillage potential improving soil hydro-physical properties and crop yield. Six mono and double cropping systems of continuous cotton (CCF), cotton/corn (CMF), continuous corn (MMF), corn/soybean (MSF), continuous soybean (SSF) and soybean/cotton (SCF) on a fourteen year non-tilled fine-silty, mixed, active, thermic Oxyaquic Fragiudalf were examined and compared. Two soil depth increments between 0-300mm were sampled and tested in laboratory or examined in the field in 2015 and 2016 for dry bulk density (BD), cone penetration resistance (CPR), soil water content (SWC), water retention characteristics (SWRC), pore size distribution (PSD), wet aggregates stability (WAS), aggregate size distribution (ASD), water infiltration properties and field saturated hydraulic conductivity. In general, cropping systems exhibited considerable variability along the range of soil hydro-physical factors particularly at the 150-300mm soil depth. Thus, the favorable soil physical quality was best defined based on groups of treatments instead of individual ones. In general crop rotation, did not show clear advantage over monoculture. None of the cropping systems significantly affected the bulk density and cone penetration resistance. Presence of corn in rotation increased the mean value of WAS, water infiltration and soil water content in lower matric potentials compared to treatments without corn while soybean showed an intermediate effect. This study suggests that the effect of cropping system on soil hydro-physical properties is more evident at soil surface layer and its magnitude is more related to the crop species relative to the singular or rotational cropping.