• Energy Research

Faced with the challenges posed by climate change, Serbian viticulture is looking for sustainable solutions for adaptable production. This study shows that grass is a multifunctional tool for overcoming the challenges of intensive viticulture while maintaining the quality of the grapes. In a three-year research experiment (2020–2022), the maintenance of an inter-row sward in a vineyard with four certified high-quality French Cabernet Sauvignon clones was investigated, and its effects on the ampelographic composition of the grapes and the quality of the grape juice (must) were studied as a function of wine quality. A grass sward was established between the rows as a biological soil management system and as a climate change adaptation measure in a high-intensity viticultural system. A grass–legume mixture was used as an inter-row cover crop, with nitrogen applied in two doses (50 and 100 kg ha−1) in spring. The growth of the grasses responded to the nitrogen fertilisation, which was reflected in the biomass production, surface cover and nitrogen content in the biomass. At the end of the study, the biomass of the grass increased threefold when a high dose of nitrogen was applied compared to the non-fertilised grass. In contrast to the effects of nitrogen on the sward, N has no effect on the quantitative or qualitative parameters of the grapes. Clone 169 was separated for most grape mechanical parameters such as the bunch mass, all berries and the bunch stem; clone 15 showed the best grape juice quality parameters such as the sugar content and glycoacidometric index. The results show an option for climate change adaptation in viticulture that can mitigate the effects of rising temperatures, contribute to soil conservation and carbon storage in biomass and enable timely interventions in vineyards after heavy rainfall by creating accessible paths within the vineyards. The three-year effect of the different nutrient management of the sward in the inter-rows of Cabernet Sauvignon showed that the interaction between the two systems, sward and vine, is low and has no negative impact on the ampelographic and qualitative grape parameters.

Second-generation biofuel production systems are significantly better than first-generation systems. However, the size of areas in which the energy crops are grown depends on public support, and it decreases if public support is missing. Despite all the environmental and economic benefits, perennial energy crops do not currently play a significant role. It is believed that available land areas will be a basic limiting factor for cultivating biofuel crops in the EU. On the other hand, there is significant untapped potential for bioenergy production in abandoned and marginal land in Southeast Europe. At the same time, perennial energy crops are investments with certain risks. Economically viable production of dedicated energy crops will be difficult to achieve on most lands classified into V-VIII land capability classes. In terms of the risk of farming investments, maize has an advantage over all perennial energy crop systems. We have identified 10 types of risks for successful production of energy crops: (1) Crop water supply; (2) Weed infestation in crops; (3) Risks of frost damages; (4) Crop lodging; (5) Crop diseases and pests; (6) Short harvest periods and variable yields; (7) Economic viability of cultivation on land areas of lower land capability class; (8) Influences of agricultural practices and agro-ecological conditions on biomass quality; (9) Storage of harvested biomass and fire hazard; and (10) economic sanctions, war, and war surroundings. Although the cultivation of perennial energy crops has a perspective, it must be systematically planned and further improved.

Due to the air temperature increase, longer growing seasons and erratic rainfalls in the last two decades, natural grasslands like meadows or pastures grow in unfavourable climatic conditions that disable the regeneration. The aim of this work is to assess the impact of climate changes on the water requirement of grasslands in Serbia. The results of ensembles of nine regional climate models from the EURO-CORDEX database were used to analyse future climatic conditions. As the most probable value, the median of scores obtained for each ensemble member was considered. The period of 1986-2005 was used as the reference. The time slices in future periods are: 2016-2035 (the near future), 2046-2065 (the mid-century) and 2081-2100 (the end of the century). Analyses were conducted for two scenarios of GHG emissions: RCP4.5 and RCP8.5. Permanent grasslands will be more prone to drought risks in the future. Water shortage could be expected at the end of May when the water stored in the soil will be depleted by the duration of drought until September heavy rains. According to both scenarios, an increment of water requirement of 7% could be expected in the near future. The RCP4.5 scenario projects an increase in the water requirement in the range of 10.7-24.2% from the mid to the end of the century. The less favourable but more realistic RCP8.5 scenario projects a water need increment in the range from 4% to 14 % in the mid-century and 28.4-41.9% toward the end of the century. Recent research indicates that drought resistance will be developed through natural diversity and the spread of species resistant to high temperatures and water scarcity.

Monoculture and intensive use of mechanization and inorganic chemicals are leading to degradation and erosion of our soils and agro-ecosystems. At the same time, the production of animal feeds that are rich in protein is constantly decreasing in many European countries. Modest cultivation needs, favorable content of nutrients, and beneficial effect on the environment, make field pea and oat mixtures promising crops to tackle these issues. In three growing seasons and without irrigation or fertilisation, we have examined two basic field pea cultivars (Kosmaj, OS Adam) and one leafless cultivar (OS Letin) intercropped with oat (NS Jadar), with seeding rates, field pea: oat – 100:10%; 100:20%. Results have shown that basic type cultivars have better overall development and higher yields compared to leafless cultivar, whether grown as single crops or in the mixture. Basic cultivars (OS Adam, Kosmaj) achieved higher protein content, compared to cultivar Letin, 163.9 g kg-1 , 153.3 g kg-1 , 136 g kg-1 , respectively. Yields were higher in 100:20% mixtures, compared to 100:10% mixtures and single grown crops, and we conclude that intercropping these species is superior to cultivating them separately. Protein content wasn’t significantly different between two seeding rates, thus seed rates shouldn’t be lower than 100:20%. 

Pri proizvodnji semena trava se stvara velika količina biomase koja je slabijeg kvaliteta za ishranu domaćih životinja, ali može biti pogodna za korišćenje kao izvor energije biljnog porekla. Na primeru gajenja dve travne vrste, italijanskog ljulja tokom 4 godine (2003-2006) i visokog vijuka tokom 2 godine (2014-2015) za seme, kroz različite mere agrotehnike (varirajuće načine setve i đubrenja azotom) su prikazani potencijali godišnje produkcije biomase. U skladu sa zemljištem i osobinama trava su primenjeni sledeći međuredni razmaci: 20, 40 i 60 cm za italijanski ljulj i 15, 30, 45 i 60 cm za visoki vijuk, setvene norme od 5, 10, 15 i 20 kg/ha za obe vrste i prolećna prihrana sa 0 i 75 kg/ha N visokog vijuka i 0, 50, 100 i 150 kg/ha kod italijanskog ljulja. Italijanski ljulj je tokom 4 godine ispitivanja na području Mačve imao maksimalni prinos od 8,8 t/ha iz dva otkosa, u prvoj godini proizvodnje semena, pri povoljnim meteorološkim uslovima. Visoki vijuk je u prvoj godini proizvodnje semena u uslovima južnog Banata ostvario maksimalno 10,6 t/ha iz dva otkosa, pri najvećem međurednom rastojanju gajenja (60 cm), kao i 15,1 t/ha u drugoj godini na istom međurednom rastojanju. Prinosi biomase trava ostvareni uz skromnu agrotehniku, u sklopu proizvodnje semena trava, ukazuju na značajan potencijal za proizvodnju bioenergije. During grass seed production, a large amount of low forage quality biomass has been produced. Tall growing perennial grasses such as tall fescue (Festuca arundinacea L.) and Italian ryegrass (Lolium multiflorum Lam.) can be used as an alternative source for bioenergy production as they can be grown in less cultivated areas, their residues in seed production could be valuable energy source and can be potentially used as a dual purpose crop (bioenergy and forage). In this research, potentials of yearly biomass production of two important forage grasses grown for seed (Italian ryegrass and tall fescue) varying modes of sowing and nitrogen fertilisation were shown. As a byproduct, postharvest residues of Italian ryegrass reached to 8.8 t/ha in the Mačva region in favourable weather conditions, during 4-year production, while tall fescue reached in southern Banat 10.6 t/ha in the first and 15.1 t/ha in the second year of production.