Corn productivity and soil characteristic alterations following transition from conventional to conservation tillage

Abstract

Compared to conventional tillage (CT) system (e.g. moldboard plowing (Moldboard-CT) and chisel plowing (Chisel-CT)) adoption rate of conservation tillage systems (e.g. no-till (NT) and strip-till (ST)) in surface- irrigated farms is considerably low. A three-year field study was conducted to evaluate corn (Zea mays L) productivity in four tillage systems ranging in intensity of soil disturbance (i.e. Moldboard-CT, Chisel-CT, ST, and NT) in a furrow-irrigated field. Averaged over three years, corn grain yield was higher in Moldboard-CT (2.9 Mg ha−1) and NT (12.1 Mg ha−1) systems than yields in Chisel-CT (10.9 Mg ha−1) and ST (10.3 Mg ha−1). Tillage system did not affect soil pH, EC, total organic carbon (TOC), and dissolved organic carbon (DOC) in 0–15 soil depths under Chisel-CT, ST, and NT compared with Moldboard-CT. No significant differences were found between tillage systems in terms of saturated hydraulic conductivity (Kfs) and bulk density, yet soil available water capacity (AWC) and the wet aggregate stability were positively affected by adopting reduced tillage. Economic analysis showed that Return on Investment (ROI) in NT was greater (0.93) than that in CT (0.88), although net return from Moldboard-CT was $44 ha−1 greater than that of NT. The small difference in net return between Moldboard-CT and NT, along with the positive trend observed in soil properties as a result of shifting to NT, indicates the potential of NT to improve corn production sustainability in surface-irrigated agroecosystems in mid- and long-term.