Effect of Time of Harvest of Vetch (Vicia sativa L.) on Yields of Subsequent Barley in a Dry Mediterranean Environment

Abstract

The introduction of annual feed legumes into the intensifying systems of barley monocropping in dry-area Mediterranean agriculture would reduce pest and disease risk and increase sustainable productivity. Potential modes of legume utilization by small ruminants - as green grazing, hay, or mature grain and straw - imply different times of harvest removal with possible consequences for the subsequent barley crop. In nine two-year trials, barley following green-grazed common vetch (Vicia sativa) always outyielded barley following vetch cut as hay or harvested at maturity, albeit in some years by small and non-significant margins; mean differences in barley grain and straw yields between green-graze and mature vetch treatments were around 20 %. The main mechanisms implicated are carryover to the barley of small amounts of soil water unused by early-harvested vetch and enhanced nitrogen availability where active vetch root systems were killed by removal of the above-ground crop.