Effects of 16-Year Woodchip Mulching on Weeds and Yield in Organic Farming
To test the possibility of using hedgerow woody waste for weed control in arable organic farming, a 16-yr fi eld trial with a typical organic crop rotation using three rates of woodchip mulching (WCM) was conducted in Southwest Germany. Winter cereals, fodder crops, and legumes representative for this region were included in the crop rotation. Th e woodchips were produced from cuttings of the hedgerows on the farm and were applied to the fi eld in rates of 0, 80, and 160 m3 ha-1, respectively (control, WCM80, and WCM160). Weed infestations, including weed density in spring, weed biomass at crop harvest and weed seed bank, were measured in selected years. Crop yields were recorded yearly. Soil temperature and soil mineral N content were measured in selected years. In general, mean weed density was reduced in WCM160 (135 plants m(-2)) compared to WCM80 and the control (150 and 160 plants m(-2), respectively). Th e relative weed density averaged across the two WCM levels was 91% of the control on average and showed no trend over time. Th e grain yield of cereals and faba bean (Vicia faba L.) did not signifi cantly diff er between the mulching treatments. Th e relative crop yield of plots with WCM compared to the control showed a decreasing trend over time. Soil temperature and diurnal temperature variation were lower in WCM160 compared to the control. Generally, combined with an adapted fertilizer application, WCM in a specifi c amount could be an effi cient tool to control weeds in organic farming without yield loss.
Author(s): Xu, JL; Gauder, M; Zikeli, S; Mohring, J; Gruber, S; Claupein, W
Journal: Agronomy Journal