LAUSR

The purpose of this work was to investigate whether weed infestation and weed coverage could be managed using less non-inversion soil disturbance. The study was carried out in a degraded chernozem soil in a long-term trial where five ploughless tillage treatments were applied in addition to the mouldboard ploughing treatment: subsoiling, tine tillage (deep and shallow), disk tillage, and direct drilling. In this paper results of weed surveys are evaluated in winter wheat (Triticum aestivum L.) relation, since this crop was grown in six seasons inside of 14 years. Weed surveys were carried out four times in a season using the Balázs-Ujvárosi method, which is based on the ground coverage of the weeds. A high degree of weed coverage was found in the early years of the trial at the ploughless treatments, and particularly at the direct drilling system. During the six years of the wheat, weed coverage significantly decreased in all treatments, and the number of species also dropped from 18 to five. Weed coverage most often decreased in the order: direct drilling > disking > tine tillage (deep) > tine tillage (shallow) > subsoiling > ploughing. We can conclude that the reasons for the decrease in weed coverage were the timing of tillage treatments, the high ratio of cereals in the crop sequence, and the timing of the chemical weed control application, once in the springs and second in cereal stubbles by the end of summer. Although data of grain yields of the winter wheat were supplementary to the evaluation of the changes in weed coverage, they were similarly connected with the tillage-induced soil condition. This study shows the possibility of the weed coverage decrease by the well-adopted soil tillage, including ploughless systems.