The evaluation of total weed density and seed bank of agricultural landscapes as an example of the Steppe Zone of Ukraine

Abstract

A high degree of weed infestation of agricultural ecosystems poses a significant threat to high crop yields, which determines the problem of weed control as one of the most urgent in steppe agriculture. The research aims to assess the level of total weed density and seed bank of various components of agroecosystems in the steppe zone of Ukraine. The methods used to determine the species composition of weeds, their quantitative and weight accounting and harmfulness were statistical and mathematical. It has been established that the main reason for the high negative impact of weeds is the weed seed bank of soils, which reaches 452 million seeds per hectare in land being actively used for agriculture and 11 million hectares in natural ecosystems. In agroecosystems, the decisive factor for effective regulation of weed seed banks is the sustainability of crops (as part of an ecosystem dominated by 1 plant species), methods of basic tillage and measures to prevent the generative productivity of weeds. According to the impact on the yield of winter wheat, corn, sunflower and spring barley, different tillage systems (ploughing, disc tillage, no-tillage) in the crop rotation were significant, where the no-tillage system was inferior to disc tillage, depending on the fertilization background, by 0.21-0.22 t/ha and ploughing – by 0.19-0.40 t/ha due to increased weed infestation of crops, as well as the presence of a significant amount of carrion and leaf mass of the predecessor on the field surface. The practical value is determined by an improvement of the system of weed control in crop rotations of adaptive agriculture and environmental safety