Effect of minimum tillage and crop sequence on crop yield and quality under irrigation in a southern Alberta clay loam soil

Productivity losses due to soil erosion are less obvious in irrigated land, so farmers in southern Alberta have been slow to adopt conservation tillag e. Moreover, local information on the effects of the tillage systems in an irrigated (sprinkler) soil on the performance and yield of cereal and row c rops is limited. This study examined the effect of tillage and crop sequenc e on yield of soft white spring wheat (Triticum aestivum L.), grain legumes (pinto bean, Phaseolus vulgaris L., or pea, Pisum sativum L.) and sugar be er (Beta vulgaris L.). Two tillage systems (conventional tillage (CT) and m inimum tillage (MT)) and two crop sequences (Sequence 1: spring wheat, suga r beet, spring wheat, legumes, and Sequence 2: spring wheat, spring wheat, legumes, sugar beet) were evaluated in a split-split plot design. After the start up year (1994), one cycle of the two 4-year crop sequences was compl eted (1995-1998) with all the crops of a sequence present each year. Wheat yield varied between 4335 and 6309 kg ha(-1), legume yield between 459 and 2866 kg ha(-1). and sugar beet yield between 53.1 and 66.3 Mg ha(-1). All t hree crop yields were not significantly affected by tillage system over the study period. While there were no significant differences in soft white sp ring wheat and annual legume yield between the two crop sequences studied. sugar beet yield was significantly higher in Sequence ? in 2 of the 4 years . The crop sequence generally favored whatever crop follows legumes. Thus. soft white spring wheat yield benefited from Sequence 1 while Sequence 2 fa vored sugar beet yield. This study demonstrates that implementation of h IT in irrigated farmland in southern Alberta is highly feasible for long-term irrigated agricultural production, and supports the importance of includin g annual legumes in the crop rotation. Crown Copyright (C) 2001 Published b y Elsevier Science B.V. All rights reserved.