Agriculture is usually developed as much and just society where there is a branch of the economy. Today, there are different directions from industry agriculture to many concepts based on ecological principles. Future of agriculture development in the XXI century will imply sustainable agriculture as the alternative to the industrial agriculture. Conventional agriculture as an intensive one has a duty to ensure maximum production in terms of quantity and quality with the low cost. For this purpose we have many cultural practices, sometimes in addition to the expected positive but sometimes with many unexpected long-term negative effects in agroecosystems. Organic agriculture is one of the most interesting current trends in agriculture completely based on strong ecological principles and the absence of application of agrochemicals (pesticides, fertilizers, hormones), GMO, etc. Organic agriculture is a holistic way of farming: besides production of goods of high quality (better flavor, high content dry matter, vitamins, antioxidants); conservation of the natural resources (soil, water) and richness of biodiversity.

Choosing appropriate tillage methods and nitrogen application are important steps in the management of wheat production for obtaining high-yield and high-quality products, as well as managing the level of weed infestation. The aim of this research was to examine the impacts of three different tillage practices (conventional tillage—CT, mulch tillage—MT, and no tillage—NT), and two top dressing fertilization nitrogen levels (rational—60 kg ha⁻¹ and high—120 kg ha⁻¹) on the grain yield and quality of winter wheat, as well as on weed infestation. The present study was carried out in field experiments on chernozem luvic type soil at the Faculty of Agriculture Belgrade-Zemun Experimental field trial “Radmilovac”, in the growing seasons of 2020/2021–2022/2023. The C/N ratio in the soil was also assessed on all plots. The results showed that the number of weeds and their fresh and air-dry weights were higher on the MT and NT plots, compared to the CT plots. Therefore, the CT system has better effects on the yield (5.91 and 5.36 t ha⁻¹) and the protein content (13.3 and 13.1%). Furthermore, the grain weight per spike and the 1000-grain weight were higher in the wheat from the CT system (41.83 and 42.75 g) than from the MT (40.34 and 41.49 g) and NT (40.26 and 41.08 g) systems. Also, the crops from the CT system had higher values of grain density and grain uniformity compared to the crop from the MT and NT systems. Fertilization with a high nitrogen level (120 kg ha⁻¹) causes higher grain yield and more weediness compared with the rational level (60 kg ha⁻¹). Top dressing fertilization in each tillage system resulted in an increase in the number of weeds, but, at the same time, it also resulted in stronger competitive ability of the wheat crop against weeds. The most favorable C/N ratio occurred on the NT plots, and the least beneficial one on the CT ones. A correlation analysis showed strong negative correlations of number (r = −0.82) and fresh weed mass (r = −0.72) with yield. It is concluded that the conventional tillage practice with a low nitrogen dose manifests its superior performance in minimizing weed infestation and maximizing crop productivity.

This paper deals with results of the effects of three tillage systems and different nitrogen fertilizer level on floristic composition of weed community in winter wheat in investigated period on the chernozem-luvic soil type. The trial was carried out on the estate experimental field of the Faculty of Agriculture - Zemun "Radmilovac" near Belgrade in Serbia. Tillage systems and fertilization with nitrogen fertilizers have a big influence on weed control and floristic composition, number of species and individuals and biomass of weeds in winter wheat. The weed community in winter wheat crops was composed of 14 weed species in both year of investigation, respectively, with dominancy of terophytes. The obtained results showed that the dominant weed species were Avena fatua L., Papaver rhoeas L., Sinapis arvensis L. and Stellaria media (L.) Vill. from annuels and. Convolvulus arvensis L. from perennials prevailed in the weed community in winter wheat crops.Conventional tillage system with nitrogen level in top dressing 120 kg ha-1 had better effect in weed control than both of both investigated conservation tillage systems (MTS and NTS) had. However, mulch tillage has not lagged behind the conventional tillage increased total weed number of individuals annual and perennial species especially fresh biomass. No-tillage system makes weed control difficult.