Behavior of the weed seed bank in an agricultural-livestock system intervened by different types of tillage

Abstract

Most of the weeds that emerge in agricultural fields come from the soil seed bank. The changes that occur in it are of vital importance for weed control and generate variations in magnitude and time of emergence. The objective of this work was to characterize the composition and abundance of the soil seed bank in two types of crops under a livestock rotation. The study area is located in "Pozo del Carril" establishment, an experimental field of the Agronomy and Veterinary Medicine Faculty at the National University of Río Cuarto (FAV-UNRC) near La Aguada, Argentina. removal (SR) and with removal (CR). The size of the seed bank, Wealth (S), Specific Diversity (H') and Equity (J') were analyzed, using the washing and sieving method. Depths were analyzed: 0-5 and 5-10 cm. The largest size of the Soil Seed Bank was found in the first 5 cm of the soil for the two treatments analyzed and the highest value was shown by the treatment without removal at that depth, showing how removal has a differential influence on the distribution of the soil and weed seed bank in the ground. Annual-summer species dominated the seed bank in all treatments, with Eleusina indicating the highest contribution. No significant differences were found between wealth, equity and diversity among the farms analyzed. It is concluded that tillage systems influence the vertical distribution of weed seeds in the first 10 cm of the soil and affect the composition and size of the weed seed bank.