The influence of an ecological and a low input system on weed density, weed diversity and weed competition in spring barley

Abstract

The field trial was carried out over the period 2000-2005 at the experimental station of the Research Institute of Plant Production in Western Slovakia. The purpose of the study was to investigate weed density and diversity and the ability of spring barley to compete in ecological and low input systems in a six years crop rotation system. The effects of farming systems on crop-weed competition were investigated by evaluating the yield and yield components of barley and weed density and diversity. Weed density and diversity were affected by the study year, systems and crop. The significantly higher weed density and diversity of 24.3 weed plants and 4.7 weed species per square meter was found in the ecological system in comparison to 7.8 weed plants and 2.4 weed species per square meter in the low input system. The weed competitiveness of spring barley with the under-sowing of clover significantly reduced weed density and diversity in both types of evaluated farming systems. The weed composition of the most troublesome perennial and annual weeds was determined for each of the six years of the study. Abundance of Polygonum aviculare L. and Cirsium arvense (L.) Scop., increased significantly in the ecological farming system in comparison to the low input system. The study considers the increased ability of spring barley to compete with weeds and the changes of the weed flora in ecological and low input systems.