Conservation tillage corn production for a semiarid, subtropical environment

Because of the extreme climatic differences between their regions, farmers in southern Texas and northern Mexico have been reluctant to adopt conservation tillage systems developed in the north-central or midwestern United States. With greater knowledge of the benefits and risks of conservation tillage practices under a semiarid, subtropical environment, producers can make better decisions regarding tillage practices. The objectives of this study were to compare the effects of conventional and conservation tillage on corn (Zea mays L.) yields and production costs during the transition from conventional to reduced tillage and provide farmers with guidelines for implementing conservation tillage in a subtropical, semiarid environment through evaluation of grain yield and production economics as affected by tillage. Conventional tillage (CT), reduced tillage with wide V-sweeps (RT), and preplant no-tillage (PPNT) were compared for both spring and fall corn production over three years. Grain yields for PPNT were lower than CT in the spring (-9%) and fall (-20%) of the first cropping year. Yields in PPNT were equivalent or up to 12% greater than CT yields in Years 2 and 3. Production costs mere lower in the PPNT than in the CT, because of the reduced number of tillage trips over the field. A three-year average of net returns for corn grown in the PPNT spring treatment was $47 ha(-1) greater than RT, and $104 ha(-1) more than the CT systems. Average fall corn net returns over three years for the PPNT were $5 ha(-1) more than RT and $101 ha(-1) more than CT systems. Average net returns from PPNT for spring and fall cropping seasons over three years was $23 ha(-1) greater than the RT and $101 ha(-1) greater than CT. Greater economic returns and lower production costs of PPNT compared with CT systems for all seasons and Sears were the result of reduced energy and operator time requirements. The conservation tillage systems (RT and PPNT) resulted in greater economic returns, compared with a CT tillage system, due to both greater yields in dry Sears and lower production costs in all years.