There are considerable differences between the EU-15 countries and Central and Eastern European (CEE) countries in the application rate of phosphorus (P) fertilizer and manure as well as in the climate and erosion patterns, but the eutrophication of surface waters is a common problem. The availability of information on the contribution of the CEE countries to European surveys on eutrophication is not adequate, because the amount of data available from these countries is small. There is thus a need to compile more comprehensive data sets for better assessment. Recent changes in agricultural practices, and their impact on the trophic status of surface waters in CEE countries, have been evaluated using a few selected pressure and state indicators (phosphorus balance, phosphorus status and erosion of agricultural land, P loss risk index, chlorophyll a, total and orthophosphate content of water) by compiling and analysing data from the literature. In the CEE countries, small annual P balances ()7 to +6 kg P ha )1 ) and declining levels of soil available P (proportion of soils adequately supplied with P dropped to between 10 and 50% of total area) may lead to low yields and economic difficulties. Only 11% of the variation in total phosphorus (TP) in rivers studied could be attributed to the calculated P loss risk index, and thus to the impact of differences in the agricultural diffuse source P load. The generation of more consistent data sets should be pursued for the whole of Europe in order to derive more powerful indicators. A refined P index could be one of the best indicators of eutrophication. Recent changes in the trophic level of surface waters could be attributed to a large extent to the change in point source P loads, i.e. to the diminishing amount of P load from municipal and industrial wastewater. The short-term improvement of water quality in the CEE countries will require further improvements in wastewater treatment, but long-term improvement will only be achieved by reducing diffuse P losses from agriculture, possibly involving changes in the land use pattern and in farming practices.

The objective of this research was to quantify the effect of the application of organic fertilizers: farmyard manure, vermicompost, spent mushroom compost, under two different ground cover management systems (black polyethylene and wheat straw mulch) on soil nutrient levels and strawberry yield during a two-year production cycle. The application of organic fertilizers, in the amounts equivalent to 170 kg ha -1 N, had the greatest impact on the concentration of available phosphorus, which was significantly higher on fertilized plots than on the control even two years after the application. The plots fertilized with farmyard manure and mushroom compost had higher concentrations of available potassium than the control, while the application of vermicompost did not affect the concentration of available potassium in the soil. The application of composts did not affect the concentration of available microelements in the soil, while the concentrations of Fe, Zn and Cu in the year of the organic fertilizers application were significantly higher on farmyard manure fertilized plots than on the control. The application of all three organic fertilizers had a significant effect on the mineral N concentration in the soil only in the year of the application and the following spring. However, the plots covered with polyethylene mulch had a higher mineral N concentration than the control at all sampling times. The concentration of available microelements was significantly higher in soil covered with black polyethylene mulch than in soil covered with straw mulch. Preplant application of organic fertilizers led to increase of yield, ranging from 14.3% in vermicompost treatmet to 17.3% in the farmyard manure treatment in relation to the control, only in the 1 st fruiting year. However, the application of polyethylene mulch facilitated a higher strawberry yield than straw mulch in both fruiting years.

Condition factor and organosomatic indices of fish represent a way of monitoring environmental factor influence on fish. The rainbow trout (Oncorhynchus mykiss, Wal.) individuals that were used in the work originated from different brood stock and different fish farms. Spawning was carried out on five selected fish farms. After that, the breeding eggs were delivered in Klasnik hatchery where the same environmental conditions were provided during embryonic development and cultivation of all five groups of individuals. As a conditioning factor in this work Fulton's condition factor and coefficients of the heart, liver and spleen were analyzed. In all individuals we determined the total length, standard length and body mass. In total, fifty individuals, which were divided into five groups form five brood stock, were analyzed. The results show significantly different values for the condition factor and organosomatic indices between some of the analyzed groups.

In order to achieve a high yield and quality of apple fruit, more effective ways of fertilization are required in the modern, high density apple orchards. The objective of this research was to determine the efficiency (partial nutrient balance, PNB) of different methods (foliar and fertrigation) and forms (chelates and salts) of microelements application in relation to the levels of N fertilization in apple orchard cultivar (‘Golden Delicious’). The combined effects of these fertilizers on the number of apple fruits per tree and on the yield per tree were also studied. Foliar application of Mn, Zn and Fe had significantly higher partial nutrient balance values compared to the soil application in both years of the experiment. However, most of the PNB values were below 10% indicating relatively low efficiency of the applied fertilizers with microelements.

Biofortification of forage crops has an important role in improving the quality of plants used for animal nutrition. The field experiments were conducted in three consecutive years in Subotica, Serbia, in order to investigate the effect of Se, Zn, and Cu foliar fertilization on the yield, Se and Zn contents and nutrient efficiency, as well as on other mineral compositions of alfalfa hay. The treatments were as follows: i) control without fertilization, ii) 5 g Se ha-1 , iii) 10 g Se ha-1 , iv) 0.5 kg Zn ha-1 , v) 1 kg Zn ha-1 , vi) the combination of these two elements (0.5 kg Zn ha-1 and Se 10 g ha-1) and vii) 2% Cu solution. The application of Se, Zn, and Cu had no effect on dry yield or on crude protein, P, K, Ca, Mg, Fe, Mn, Mo, and Co contents in alfalfa hay. However, Se, Zn, and Cu fertilization significantly increased the contents of Se, Zn, and Cu in alfalfa hay. The results showed that Se and Zn contents in plant biomass were significantly correlated with the applied doses of Se (r=0.99) and Zn (r=0.99). The production years of alfalfa and the weather conditions proved to be significant factors in fertilization efficiency.