Inter- and Double-crop Yield Response to Alternative Crop Planting Dates

Abstract

Planting date is an integral part of a successful double-crop system, and in intercropping it can affect crop yields. Cool-adapted species that can be frost-seeded benefit from an earlier planting date by taking advantage of unused light and space between rows of slow-growing spring or fall crops such as winter wheat. This research evaluated differences between early frost-seeding, mid-season relay-intercropping, and double-cropping planting dates of alternative crops (buckwheat, sunflower, radish, faba bean, and hairy vetch) on wheat and alternative crop yields. Field research took place in 2012 and 2013 near Novelty, Missouri. Wheat yields were affected by cropping system and alternative crop selection with significant differences up to 455 kg ha-1. Alternative crop yields were harder to determine. In 2012, emergence occurred but drought precluded alternative crop yields for the frost-seeded and relay-intercrop systems. However, in 2013, planting date and cropping system affected alternative crops differently, with land equivalent ratio (LER) values showing an advantage for alternative crops when they survived past emergence. In both years, frost-seeding provided yield advantages among almost all alternative crops. This research shows that farmers could increase their yield potential for a given field and perhaps produce additional forage or green manure yields in a year with a less severe drought by using alternative crops.