A soil tillage system adjusted to the soil type and agro-ecological conditions, together with the optimal nutrient supply, is a prerequisite for high maize (Zea mays L.) yield. However, there is little knowledge about the influence of soil tillage and nitrogen (N) rates on maize grain quality. A study was initiated in 1978 in Zemun Polje, Belgrade, Serbia, on the chernozem soil type. The effects of three N rates—0, 180 and 240 kg N ha⁻¹—within three tillage practices—no-tillage, reduced and conventional tillage—and their influence on grain yield (GY) and the content of proteins, starch, oil, total tocopherols and carotenoids, phytic phosphorus (Phy), glutathione (GSH), phenols and inorganic P (Pi) in maize grain were analysed in the period 2016–2018. Differences in maize GY were 2.57 and 3.01 t ha⁻¹ for reduced- or no-tillage, respectively, in comparison to conventional tillage. Conventional tillage and higher N rates contributed to the increase in maize yield and the grain nutritional quality with regard to the increased level of proteins, GSH and Phy. On the other hand reduced inputs were beneficial only for grain quality, in relation to the increase in tocopherols and phenols.

The objective of this study was to evaluate the impact of two foliar fertilizers applied on five maize (Zea mays L.) lines. Fertilizers were applied at different growth stages of maize, during three consecutive years (2010–2012) at the experimental field of the Maize Research Institute “Zemun Polje”, Serbia. Maize growth parameters such as fresh matter, height, leaf area and grain yield were recorded. Foliar fertilizer with amino acids (FAA) was more advantageous to maize plants compared to fertilizer containing phosphorus (FP) as a main component. Applied FAA has shown positive effects by increasing fresh matter, leaf area index, and plant height in all three years. In 2012, due to unfavorable meteorological conditions, grain yield and harvest index were very low, compared to the previous two years, although, positive effects on morphological traits were observed 21 days after treatments (DAT), as well as in the anthesis stage. The best results of 30% of grain yield and harvest index increase were recorded in line L1 in 2010 and 2011. The same line had an increase of more than 40% of fresh matter and leaf area on average for all three years. The positive effects that have been noticed in this research could recommend foliar fertilizing with fertilizer containing N in a form of an amino acids complex.

Genetic potential of maize hybrids grown in Serbia is 10-15 t ha-1 , while the average yields are considerably lower. There are many reasons for this. At first, it is well known that drought is present often in some parts of country. Some soils are not suitable in the same degree for intensive maize production, application of mineral fertilizers is insufficient, mechanization is outdated and arable farms are small and fragmented. During the period 19652012 high variations in precipitation were present during the maize vegetation. The yearly average precipitation sum was 688.9 mm, with 397.5 mm during vegetation. According to precipitation amount, years were divided into groups: I 200-300 mm 7, (15%); II 301-400 mm 21, (44%) and III 401-500 mm 14, (30%), and IV in 5 years (11%) more than 500 mm of precipitation was present. The highest average yield in Serbia was achieved in 1991 (5.95 t ha-1) and the lowest in 2000 (2.44 t ha-1). The average yield increase was 114 kg ha-1 per year from 1965 to 1985, and it was 22 kg ha-1 per year from 1986 to 2012. In experiments during the period 1998-2012, when the standard cropping technology (MSY) was applied, the average grain yield was10.46 t ha-1 for hybrids of FAO 300-400, 10.39 t ha-1 for hybrids from FAO 500 and 11.38 for FAO 600-700. There were no significant differences in yield between hybrids from examined FAO groups. According to this, average maize yield includes only 44.2% for FAO 300-400, 44.5% for FAO 500 and 40.6% for FAO 600700 utilized maize genetic potential. The significant improvement of maize production demand the strategic long-term program, where it will be elaborated: merging of land properties, increasing of the areas with irrigation and increasing of the technology level in maize cropping.

Intercropping systems could improve utilization of the most important resources (soil, water and nutrients), provide a better control of weeds, pests and diseases, and finally higher productivity, especially under rain-fed growing conditions. This study aimed to determine the effects of three maize (Zea mays L.) prolific hybrids (FAO 500, 600 and 700) and the spatial intercrop patterns on the above-ground biomass and grain yields of maize and soybean (Glycine max L. Merrill), on chernozem soil type at Zemun Polje, Belgrade, in 2003, 2004 and 2005. The experimental design was a complete randomized block with four replications and three treatments: 3 rows of maize and 3 rows of soybean in strips for each maize hybrid (three variants, 3 rows of maize and 3 rows of soybean in alternate rows for each hybrid (another three variants) and monocrops of both maize and soybeans. To optimize the ecological and economic benefits of maize/soybean intercrop in terms of yield, variety selection and compatibility of the component crops should be made using established agronomic management practices involving the two crops. Suitable maize varieties for maize/soybean intercrop systems are varieties that have less dense canopy. These varieties would therefore have lesser shading effect to the understory beans. However, establishment of an appropriate spatial arrangement of the component crops would be essential to alleviate negative effects especially on the less competitive crop. The intercropping system in alternate rows showed significantly higher above-ground biomass and grain yields in comparation with both the strip intercropping system and maize monocrops in 2004. Soybean gave significantly lower above-ground biomass and grain yield in intercrops than in monocrops. Maize prolific hybrid growing in intercropping with soybean as legume crop, increased productivity of cropping system, especially in favourable agroecological conditions. Maize and soybean yields reduction could have also been due to interspecific competition for resources such as nutrients and water. Moreover, performance of the currently grown varieties in the semi-arid regions depends on the amount of rainfall received during the growing season.

Cover crops (CC) are an important low-input strategy in sustainable agricultural systems. The impact of different CC (common vetch, field pea, winter oats, fodder kale, common vetch + winter oats and field pea + winter oats), organic mulch, control treatment-fallow, and bio-fertilizer (BF) application, on yield and quality of sweet maize kernel was evaluated. CC biomass was higher in mixtures: field pea + winter oats, and common vetch + winter oats, as well as in fodder kale. Kernel yield and its chemical composition varied significantly by CC, BF, year, and their interaction. Organic mulch enhanced the concentration of sugars and glutathione in maize kernel. BF increased kernel yield, the concentration of sugars, vitamin C, Mg, Fe, Zn, and reduced phytate concentration. The highest Mg and Mn concentration in maize kernel was achieved with fodder kale, Zn concentration with common vetch + winter oats + BF, and Fe concentration with winter oats. The same treatments expressed the highest impact on variability in concentration of the phytate, phenolics, and yellow pigment, thus affecting further bio-availability of essential elements. Results indicate that in a semi-arid climate, under rain-fed conditions, CC such as fodder kale and winter oats + common vetch could enhance sweet maize productivity and kernel quality, serving as an important part of a sustainable cropping system, to facilitate food security.

Weed control in corn is a major challenge due to increasing problems with highly dominant weed species and herbicide resistance evolution. Common lambsquarters and johnsongrass constitute up to 80-90% of the weed population in many spring crops such as soybeans, sunflower or corn in Serbia. Currently, acetolactate synthase (ALS)-inhibiting herbicides such as the systemic selective sulfonylurea nicosulfuron are most commonly used for chemical weed control of those species. A better understanding of the impact of nozzle type and adjuvants use on nicosulfuron efficacy can help to improve control of common lambsquarters and johnsongrass and minimize herbicide resistance development. Field trials were conducted in Serbia from 2020-2022 to evaluate the impact of two adjuvants (a non-ionic surfactant and a mineral fertilizer ammonium-sulphate) and two nozzle types (drift-reducing nozzles and flat-fan nozzles) on common lambsquarters and johnsongrass control using nicosulfuron. Satisfactory biomass reduction of common lambsquarters (83 to 87%) and johnsongrass (83 to 97%) was achieved after nicosulfuron application. Adding a non-ionic surfactant increased the biomass reduction for common lambsquarters (94 to 98%) and johnsongrass (90 to 100%) independently of the nozzle type used. Selection of nozzle type did not show consistent effects on common lambsquarters and johnsongrass control. Nicosulfuron efficacy was increased with NIS adjuvant for both nozzle types compared to nicosulfuron solo for both species, and XR nozzles on average resulted in a higher efficacy for common lambsquarters compared to TTI. Adding the mineral fertilizer ammonium-sulphate adjuvant resulted in lower biomass reduction for both nozzle types and weed species (65-78% and 61-91% for common lambsquarters and johnsongrass, respectively). Corn grain yield was predominantly influenced by annual meteorological conditions and adjuvant type added to nicosulfuron. This research suggests that addition of the non-ionic adjuvant is an essential factor for successful control of common lambsquarters and johnsongrass in corn and enables use of drift-reducing nozzles.