Effect Long-Term Management System on Soil Weed Seed Bank

Abstract

Long-term monoculture has a de-stroying impact on plant production, while crop rotation is known as a more eco-friendly approach as provides diversification in crop management systems, modifies intensive pressure on the agricultural ecosystem, utilizes various soil horizons, and prevents the establishment of specific pests and weeds. The aim of his research was to answer: How management system over 50 years of specific continuous crop management programs (crop rotation and fertilization) effect on weed populations? This study was conducted in the experimental site of the Institute of Field and Vegetable Crops of “Plodoredi”, Rimski Šančevi, Novi Sad, Serbia. It has been estimated three monocultures of maize, wheat and soybean, 2-year crop rotation (winter wheat-maize) with and without chemical fertilizer and 3–year crop rotation (winter wheat-soybean-maize) with and without chemical fertilizer and manure. Soil samples were taken six times from 2014 to 2017 prior to sowing and after harvesting each year. Weed seeds were extracted from soils and identified and counted by species. Mixed model analysis was used to determine the effect of the crop sequence and fertilizers on weed seed bank. To compare the strength of the treatment, it calculated the log-worth with their P-values. Upon the data of a long term experiment of crop rotation, could approve that crop rotations with more crops in the sequence are significantly effective in maintaining weed population. Therefore, will be a more sustainable crop production, chemical fertilizers would imbalance the plant population diversity and manures with high number of weed seeds have potentials to totally vanish crop rotation effects. Mixed model analysis suggests that on over 50 years of the management practices crop sequence × fertilizer interaction had the highest effect (log-worth = 64.7), followed by the triple interactions between crop sequence × fertilizer × soil depth (log-worth = 30.5). The number of seeds in soil significantly decreased from surface layer to deep soil. The crop sequence efficiency in decreasing weed seed bank was highly dependent on the fertilizer management, as with chemical fertilizer, the three years crop rotations had significantly lower seed bank, while with manure, the effect of crop rotations was eliminated.