Tuesday, November 6, 2007
163-11
Rotation and Tillage Effects on Crop Yields Over 20 Years in Ontario.
Bill Deen1, Ken Janovicek1, and Andreas Meyer-Aurich2. (1) University of Guelph, University of Guelph, Crop Science Building, Guelph, ON N1G 2W1, CANADA, (2) Leibniz-Insitute of Agricultural Engineering, Potsdam, Germany
Choice of crop rotation and tillage system can have significant effects on whole farm productivity and(or) income, the magnitude of which is affected by crops included in rotations and soil type. The objective of this study was to evaluate the effect of crop yield and economic returns of corn (Zea mays L.) based crop rotations typical of the northern corn belt. Economic analysis was based on crop yield responses observed on a long-term (1982-2001) crop rotation-tillage experiment located at the Elora Research Station near Elora , Ontario . The soil is a well drained Woolwich silt loam (Typic Hapludalf) with a growing season rated as receiving 85 RM. Crop rotations were continuous corn plus six 4-year crop sequences consisting of 2 years of a rotation crop followed by 2 years of corn. The rotation crop sequences were 2 years of soybean (Glycine max L. Merr), soybean-winter wheat (Triticum aestivum L.), soybean-winter wheat underseeded with red clover (Trifolium pratense L.), 2 years of barley (Hordium Vulgare L.), 2 years of barley Underseeded with red clover and 2 years of alfalfa (Medicago sativa L.) The tillage systems were fall moldboard and chisel plow. Economic analysis suggests that diverse rotations which included wheat had greater average net returns than simpler rotations consisting of only corn or corn and soybeans. Furthermore, the economic benefit of including wheat in the rotation increased over time with the increase in net returns in the final 2 (of 5) rotation cycles associated with including wheat in the rotation that were 2 times greater than the average increase observed over all 5 rotation cycles. Higher net returns associated with more diversified rotations can be attributed to reduced risk with respect to crop price and higher yields. Even though chisel plowing had lower fuel consumption, it is more efficient to select appropriate crops and increase rotation complexity than to change the tillage system as a response to increased energy prices.