Reduced tillage field corn (Zea mays L.) production in Manitoba
Wall, David Alexander.
Field studies were conducted on field corn (Zea mays L.) under various conventional and reduced tillage cropping systems and straw management practices to determine the effect on soil physical properties, crop growth, development and yield. The performance of eight corn hybrids was evaluated under conventional and zero tillage to study the adaptability of hybrids to zero tillage cropping practices. Corn under zero tillage exhibited delays in emergence, silking and maturity, reduced plant populations, dry matter, plant height and grain yields. The negative effects of zero tillage on crop performance were attributed to poorer seed placement and lower soil temperatures. The lower soil temperatures and higher soil water content which occurred under zero tillage were attributed to the presence of a barley straw mulch on the soil surface. The performance of the corn grown under conventional tillage, in which the seedbed had been prepared the previous fall, was superior to all other treatments examined. The superior performance of the fall tillage treatment was considered to have resulted from improved seed placement and greater soil moisture. The removal of the barley straw mulch from the soil surface promoted earlier silking and maturity, increased plant heights, populations and grain yields in corn. The removal of the straw mulch resulted in increased soil temperatures relative to where the straw mulch had been retained. The eight hybrids examined exhibited similar responses to zero tillage during the growing season. At harvest, however, the hybrids exhibited a differential yield response to tillage. Four hybrids; Pioneer 3995, Pride R102, Pride R108 and Pickseed 2322 wee not affected by zero tillage, while the remaining hybrids; Pickseed 2111, Asgrow RX22, Pioneer 3992 and Funks G4065 exhibited reduced grain yields under the zero tillage treatment.