Effect of Three Tillage Systems on Weed Flora in a 3‐Year Rotation with Four Crops

Abstract

Field experiments were conducted to determine the effect of tillage on the dry weight, frequency (PF), density (PD) and species composition of the weed population. Three tillage systems (CT: conventional tillage, MT: minimum tillage and NT: no tillage) were compared in a 3‐year rotation [wheat–vetch (green manure)–cotton–barley]. Decreases in PF, mean PD and number of species were observed under NT because in this system the soil remains undisturbed, and conditions are not suitable for seed germination. In contrast, annual weeds had a higher PF under the CT system, because they mainly propagate by seed and soil tillage creates more favourable growth conditions; thus they also had a higher PD. The highest PF and PD were found for the species Sinapis arvensis and Solanum nigrum. Perennial weeds had higher PD under the NT system, because their roots cannot be destroyed by soil tillage. The number of species was not altered in CT and MT, but was decreased in NT. In winter crops, annual species under CT and MT, and perennial species under NT were observed. In cotton crops, perennial species under CT and MT, and annual species under NT were observed. The mean PD of weed species in the first crop followed the sequence NT > MT > CT and in subsequent crops followed the reverse sequence CT > MT > NT.

Evaluation of monocropped and intercropped grain legumes for cover cropping in no-tillage and reduced tillage organic agriculture

“…(Moonen and Barberi, 2004) were cut in the harvest process. The no-till seeding of cover crops can also reduce the annual weed population density as weed seeds are not incorporated into the soil and germination from the weed seed bank is not induced by tillage (Bilalis et al, 2001). During the cover cropping period, the weed growth will be reduced through cover crop-weed competition for light, water and nutrients.…”

Weed Problems, Ecology, and Management Options in Conservation Agriculture: Issues and Perspectives

“…In winter crops, annual species under CT and MT, and perennial species under NT were observed. In cotton, perennial species under CT and MT, and annual species under NT were observed (Bilalis et al, 2001). Greater weed densities in ZT than MT/CoT in a long-term study on a winter wheat-based (T. aestivum L.) cropping systems was noticed.…”

The response of weed community in soybean with conventional and conservation tillage systems on rainfed Vertisols

“…Saccharum spontaneum was observed only in the RT and NT treatments. Bilalis et al (2001) reported more of perennial weeds in the less tilled plots compared to the conventional tillage systems. Weed shifts due to tillage systems cannot be confirmed from this study because observations on weeds from the earlier years of the study are not available.…”

“…On the contrary, the RT and NT treatments had less weed diversity because of limited or no tillage intervention, respectively. Low weed diversity in the NT systems have been reported because the soil was undisturbed (Bilalis et al 2001). The conservation tillage systems have crop residue cover that maintains greater soil moisture content and that reduces the weediness as well as a reduction in population diversity (Bilalis et al 2003).…”