EFFECTS OF FERTILIZATION AND IRRIGATION LEVELS ON PHYTOREMEDIATIONPROPERTIES OF PERENNIAL RYEGRASS

The experiment was set up in the greenhouse of Faculty of Agriculture, University of Belgrade with the aim of investigating potential of perennial ryegrass (Loliumperennial L.) to grow on substrates of exceptionally unfavorable characteristics. Tailings, characterized by very poor physical and chemical properties and deficiency in nutrients were used as substrate. The research examined effects of three different fertilizers and two irrigation levels on plant growth and assimilation of Cu and Cd. There were statistically highly significant differences in plant height between plants treated with different fertilizers. Plants treated with organic fertilizer were tallest at 45.8 cm, while the plants treated with mineral fertilizer were shortest at 22.5 cm. Amounts of the assimilated metals varied between different type of fertilizers. The highest content of Cu, about 75 mg kg-1 was recorded in plants treated with mineral fertilizer and irrigated moderately while the lowest concentrations of about 30 mg kg-1were measured in the same plants after the first cutting. There were no differences among plants treated with organic fertilizers in Cu amounts,under two irrigation levels. The second cutting showed a small increase in the assimilated amounts of Cu. Highest Cd concentration of 2.7 mg kg-1 was recorded in the plants treated with combination of both organic and mineral fertilizers

Potential risks and problems in the cultivation of perennial energy crops

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

Mikrobni diverzitet kao pokazatelj remedijacije jalovine

Eksploatacija rude, i pored benefita za ljudsko društvo, dovodi do pogoršanja kvaliteta životne sredine. Kao posledica eksploatacije, dolazi do deponovanja otpadnog materijala i stvaranja jalovina sa nepovoljnim fizičkim, hemijskim i biološkim osobinama. Imajući u vidu značaj mikroorganizama u oštećenim ekosistemima, cilj ovog rada bio je ispitivanje mikrobnog diverziteta jalovine; na jednom delu jalovine izvršena je setva semena crvenog vijuka uz dodatak organskog i mineralnog đubriva (CVF), na drugom setva istog semena bez đubrenja (CV), dok je treći deo, bez setve i đubrenja, predstavljao kontrolu (KON). Mikrobni diverzitet ispitan je metodom agarnih ploča, pri čemu je određen ukupan broj bakterija, amonifikatora i gljiva, kao i prisustvo vrsta iz rodova Pseudomonas sp. i Azotobacter sp. Dobijeni rezultati ukazuju na nizak ukupan broj bakterija, amonifikatora i gljiva, dok vrste iz rodova Pseudomonas sp. i Azotobacter sp. nisu detektovane. Slaba zastupljenost mikrobnih populacija je posledica niskog sadržaja hranljivih supstanci i visoke koncentracije teških metala. Đubrenje je uticalo na povećanje mikrobiološke aktivnosti, kao i na promenu odnosa fungalnih i bakterijskih populacija, što ukazuje na oporavak oštećenog ekosistema