Diversity, spatial patterns, and competition in conventional no-tillage and organically managed spring wheat systems in Montana

Abstract

The long term sustainability of agricultural systems has become a major concern. In light of this, interest in integrated weed management systems has increased. A better understanding of ecological processes occurring within the weed community might yield insights into how to control weeds while reducing chemical inputs. The objectives of this study were to 1) compare weed species richness and diversity between conventional no-till and organic spring wheat systems, 2) compare spatial patterns of the weed community between these two systems, and 3) examine the joint effects of weed species richness and density on spring wheat performance. Objective 1 was carried out on experimental plots and three production farms in Montana. A nested plot sampling design was used to generate species-area curves. The intercept and slope of the species-area curves were then used to estimate relative α and β diversity respectively. Data indicated higher species richness, α and β diversity in organic systems. We concluded that levels of α and β diversity may serve as indicators of underlying processes occurring in these two systems.