Development and control of weeds in arable farming systems

It is investigated, whether the arable weed vegetation can perform as a characteristic to stimulate sustainable development of agriculture in Central Europe. The concept of sustainable development represents a dynamic process, influenced by ecological, economic and social aspects. Characteristics are required to integrate desired ecological aspects into farming concepts, in order to stimulate production systems which add to a sustainable development of the sector. The investigations rely on data of an arable farming system experiment (INTEX). Three farming systems called good-farming-practice (GFP), integrated-flexible and integrated-non-inversion were established from 1994 to 1998 on two sites. The systems differed in crop rotation, soil tillage, fertilisation and pesticide use. Thus, weed management comprised cultural or indirect control by plant husbandry and direct mechanical and chemical control. A residual weed vegetation after terminating all direct control in the arable crops was ex-ante intended in the integrated systems. The spring weed densities were observed in winter wheat previous to any direct control treatments. The residual weed vegetation was investigated in all crops by monitoring species numbers and total ground cover after terminating all direct control. The direct chemical control intensity was considerably lower in the integrated farming system, in which the crop rotation was extended and the soil was ploughed annually. Spring densities of problematic weeds like annual grass weeds and Galium aparine in the winter wheat crop were not higher in these systems. Higher covers of the residual weed vegetation occurred more often in the productive arable crops of the two integrated farming systems, which additionally hosted higher number of species after terminating direct control. The different system strategies, including a higher input of herbicides in the system integrated-non-inversion, averted severe problems, including those arising from the dominating species being generally problematic in arable land use.