|Morrison Jr, John|
Submitted to: Journal of Production Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 4, 1996
Publication Date: N/A
Interpretive Summary: Sustainable conservation tillage practices are needed to control water erosion in the 13 million acres of heavy clay soils located in the Texas Blacklands region. Despite high erosion potentials, conservation management practices are not well accepted at this time because of questions of timeliness of operation, yield potential, and reliability of obtaining adequate plant stands. Various levels of tillage management, which left different amounts crop residue on the soil surface and in the row had different effects on corn and grain sorghum, two of the principle crops of the Blackland region. Corn responded unfavorably to no-till operations with lower plant stands and yields compared to management systems with some tillage. There was little difference in corn response between a clean till and a minimal tillage operation. Grain sorghum responded favorably to conditions created by the no-till management practices. Farmers should consider the crop being grown when deciding on tillage practices in these high clay soils.
Technical Abstract: Sustainable conservation tillage practices are needed to control water erosion on vertisols. At this time, these practices have not been well accepted in the Central Texas Blacklands. Five levels of tillage intensity were tested for three years for effects on growth and yield of corn (Zea mays L.) and grain sorghum [Sorghum bicolor (L.) Moench] on a Houston Black clay soil (Udic Pellusterts). Tillage intensity levels included: chisel plow with secondary tillage; disk only; no-till with residue rakes at planting; no-till with midseason cultivation; and no- till. Corn plant populations were greater in tilled treatments than in no-till treatments in two of the three years. Corn above ground biomass production was generally reduced in no-till treatments early in the growing season, but by anthesis differences among treatments were not significantly different. Corn yields responded more favorably to increased tillage intensity than grain sorghum. Plant population differences accounted for much of the difference in corn grain yields, with low plant populations restricting yield in some years. Grain sorghum populations were not consistently affected by the tillage intensity. Grain sorghum biomass production was less sensitive to tillage intensity than corn. Grain sorghum yields were often increased in reduced tillage treatments. Grain sorghum appears better suited for no-till management on vertisols than corn.