Influence of Three Tillage Depths on Soil Physical and Hydraulic Properties in a Sandy Loam Soil.

Over the centuries, tillage has been an important agronomic practice that mechanically alters soil properties to enhancing soil ecosystem for growth of crops. A 4-yr study investigated the impact of no-tillage (NT), shallow tillage at a 10-cm depth (ST), and deep tillage at a30-cm depth (DT) practices on soil bulk density (BD), saturated hydraulic conductivity (Ks), and moisture content (MC) in a sandy loam soil. Soil BD was not significantly influenced by tillage in the 0-to 10, 20-to 30, and 30-to 40 cm layers for all four years. However, soil BD was significantly smaller in DT than in ST and NT at the 10-to 20 cm in 2008. Mean BD profile averaged over all years and layers resulted in the lowest BD for DT relative to ST and NT, respectively. Soil Ks was not affected by tillage during the course of study except for the 10-to 20 cm layer in 2008 where Ks results corresponded with soil bulk density results. In 2008, soil Ks values were significantly greater in DT than in ST and NT at the 10-to 20 cm layer. Soil MC was not significantly impacted by tillage at any of the four depths measured during the course of the study from 2008 to 2011. We concluded that tillage did not significantly affect BD, Ks and soil MC most likely due to the unchanging  total porosity in sandy loam soil regardless of tillage type.