Tillage and Nitrogen Rate Effects on Corn Production and Residual Soil Characteristics

CORE IDEAS: Strip tillage had relative production advantage over other tillage practices in corn production. Strip tillage showed greater water use efficiency than conventional tillage. No‐tillage showed higher residual carryover soil moisture, NO₃–N and total N. ABSTRACT: Successful corn (Zea mays L.) production in semiarid and arid southwestern United States is limited by available resources, especially water and N, and management of such limited resources need efficient on‐farm tillage and N management decisions. A 3‐yr study was conducted at New Mexico State University Agricultural Science Center, Tucumcari, NM, to evaluate the effectiveness of three tillage strategies (conventional, strip, and no‐tillage) and two N rates (196 and 308 kg ha⁻¹) on corn yield, water use, and carry‐over residual water and N characteristics. Tillage × N‐rate interaction had no significant impact on corn yield, water use, and residual soil characteristics (P > 0.05). No‐tillage showed consistent lower grain and stover yield in all three years. Strip tillage (ST) had a relative grain yield advantage over other tillage practices in 2 out of 3 yrs. Strip tillage showed higher harvesting index and greater water use efficiency (WUE) than conventional tillage (CT). No‐tillage (NT) had 20 to 45% greater residual carry‐over soil moisture than CT during the 3‐yr study period. Percent change (draw‐down) in soil profile moisture and NO3–N in each site‐year were higher in CT than other tillage treatments at both 0 to 30 and 30‐ to 60‐cm depth increments. No‐tillage resulted in higher residual carry‐over NO3–N and total N at both incremental depths in each tested year, without exception. Overall, implementation of ST in the semiarid regions has significant advantage over other tillage practices in improving the resource use efficiency in corn production.