Conservation tillage in faba bean cultivation: weed flora

Abstract

Legumes poorly compete with weeds, especially when their developmental conditions are markedly altered by the soil management practices, including ploughless tillage or direct drilling. Faba bean particularly requires a comprehensive study due to the lack of experimental data. The aim of the study was to determine the influence of tillage systems on the composition, number and dry mass of weeds. Therefore, in 2016–2018 field experiment was conducted at Vytautas Magnus University, Agriculture Academy on the basis of a long-term tillage experiment, carried out since 1988. Systems of conventional deep and shallow ploughing, deep chiselling, shallow disking and no-tillage were investigated. Weed species composition and weed density were evaluated at the beginning (BBCH 25–27) and end (BBCH 75–79) of faba bean vegetative period, biomass – at the end of vegetation. Investigations showed, that a minimal chemical control of weeds and meteorological conditions influenced weed abundance more than tillage systems. With an increase in the volume of pre-crop residues on the soil surface, the biomass of annual weeds decreased, while that of perennial and total weeds increased. The tested tillage systems generally did not have any significant impact on weed biomass, except for the warmer and wetter end of vegetative season in 2018.