No-Tillage and Drainage Influences On Gas Diffusivity of an Alfisol.

No-tillage (NT) agriculture system improves water conservation, and increases soil organic carbon (SOC) content. However, the NT system under poorly-drained soils sometimes fails to perform well because of the poor aeration. Therefore, the present study was conducted to investigate the effects of long-term tillage and drainage systems on soil gas diffusivity. Treatments included: (i) NT with drainage (ii) NT without drainage (iii) chisel tillage (CT) with drainage, and (iv) CT without drainage. The experimental research site was located at the Waterman Farm of The Ohio State University, Columbus, USA. Intact soil cores from all the treatments at 0-10, 10-20, and 20-30 cm depths were collected during summer of 2012. Results from this study show that for the 0-10 cm depth, relative soil gas diffusion under NT (27.1 ×10^-3) system was 40% higher as compare to that under CT (19.4×10^-3). The relative gas diffusion for the 10-20 cm depth for NT (19.1×10^-3) was also significantly higher as compared to CT (16.4×10^-3). On an average, relative gas diffusion for drainage system was 21.4 and 21.1% higher as compared to that under without drainage, respectively, for the 0-10 and 10-20 cm depths. Conclusions can be drawn from this study that the NT systems with subsurface drainage under poorly-drained soils improved gas diffusion, and hence improve the crop productivity.