Influence of long-term (36 years) tillage practices on soil physical properties in a grain sorghum experiment in Southeast Texas
Prabhu Govindasamy, Jake Mowrer, Nithya Rajan, Tony Provin, Frank M. Hons, Muthukumar Bagavathiannan
Abstract
Experiments were conducted to evaluate the impact of 36 years of no-tillage (NT), compared to conventional-tillage (CT), on soil physical properties in a continuous grain sorghum experiment. Results revealed that long-term tillage treatments had minimal impact on bulk density (BD), total porosity (TP), air-filled porosity (AFP), water-filled pore space (WFPS), and volumetric water content (Θv). However, water-holding capacity (WHC) was 26% greater in NT, compared to CT. Irrespective of the tillage system, soil physical properties differed across soil depth. The BD was greater at the 0 to 5, and 10 to 20 cm soil depths, compared to the 5 to 10 cm depth; further, BD was positively correlated with Θv (r = 0.47) and WFPS (r = 0.49). However, the TP and AFP values were greater (52.4% and 52.2%, respectively) at the 5 to 10 cm depth. Penetration resistance (MI) was maximum (≥ 48.11 J cm–1) at the greatest depth tested (60 cm) in both tillage systems. Overall, results indicated that NT had a positive impact on WHC. High WHC associated with long-term NT systems is expected to increase available soil water content, thereby improve productivity, especially under limited moisture environments.