Tillage and drainage management effect on soil gas diffusivity

Subsurface drainage influences the gaseous exchange in soils and improves crop productivity. Thus, gas diffusivity were monitored on a long-term drainage/tillage experiment established in 1994 at the Waterman Farm of The Ohio State University, Columbus, OH, USA. Specific objectives of the present study were to compare the gas diffusion and physical properties (bulk density and water retention) of soils managed under no-till (NT) and chisel-tillage (CT) systems with subsurface drainage management. Soils of the experimental site are classified as Crosby silt loam (Fine, mixed, mesic, Aeric Ochraqualf; fine, mixed, mesic, Typic Argiaquall). Treatments included: NT with tile drainage (NT-D), NT with no-drainage (NT-ND), CT with drainage (CT-D), and CT with no-drainage (CT-ND). The research site has been under continuous corn (Zea mays L.) cropping system since the start of the experiment. Intact core samples (n = 36) from 0–10, 10–20, and 20–30 cm depths were collected during November 2011 in three replicated plots of NT and CT systems under D and ND treatments. Results from this study showed that drainage treatments significantly influencing the relative gas diffusion (Dp/D0), is defined as the ratio of the soil gas diffusion coefficient to that in free air. The Dp/D0 for NT soils (23.1 × 10−3) were 26% higher than those for CT (18.3 × 10−3). Similarly, the ratio was 22% higher for soils under D (25.0 × 10−3) compared with those under ND (20.5 × 10−3). The tillage by drainage interaction was also significant for the Dp/D0 at the 0–10 cm depth. Corn yield was positively correlated with relative gas diffusion (R2 = 0.36). It can be concluded from this study that NT system under drainage management can improve the gas diffusivity, enhance the soil structure and increase crop yield.