Spatial relationship of weeds with soil properties in wheat field using geostatistical methods

Abstract

A field experiment was conducted during the agricultural years 2019 and 2020, using a network system with a distance of 2 × 2 m. At each network node, soil, wheat grain yield, seed bank, black grass and wild barley weed density, and biomass were measured. Soil components with high consumption had 0%–55.9% spatial correlation. The association between soil pH and EC was 50.0%–75.2%. The soil texture correlation was 0%–66.5%. The prevalence of black grass and wild barley weeds showed a patchy or clustered dispersion pattern. The kriging interpolated maps also showed a substantial relationship between the first-year seed bank and weed seedling distribution patterns and the second-year weed distribution patterns. Black grass and wild barley weeds were more prevalent in fields with low potassium and soil pH, indicating a spatial connection with soil nitrogen. Wheat grain yield in the field was fragmented, with a 50.2% spatial correlation. In the initial and subsequent years, black grass weed density correlated with grain yield inverse by 81.8% and 78.5%, respectively. Wild barley weed density and grain yield inverse had 53.2% and 63.9% geographical correlations, respectively. The first year's spatial correlation between grain yield and soil nitrogen was 81.6% and the second 80.6%. The association between grain yield and soil phosphorus was 79.4% in the first year and 85.8% in the second. This study suggests that knowing the spatial distribution of soil nutrients and weeds in a field can help determine the best wheat crop management strategy.