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.

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Key words Bradyrhizobium japonicum Dry matter yield 15N-substratum labeling technique Soybean varietiesSummary The ~SN-substratum labeling technique and other indirect methods were used to compare nitrogen (N2) fixation in soybean varieties grown in the field in Greece and Romania.Significant variation in the amount (Ndfa) and proportion of N derived from fixation (% Ndfa) was found in different varieties. With 20 kgN/ha applied to soil, N 2 fixed ranged from 22 to 236 kg N/ha in Greece and from 17 to 132 kg N/ha in Romania. In general, varieties or treatments with higher dry matter yield supported greater fixation. Also, varieties with high Ndfa had high % Ndfa and vice versa. Breeding N 2-fixing legumes for high yields at low soil N levels therefore appears to be a reasonable strategy for enhancing N2 fixation.Heavy applications of inorganic N fertilizer severely depressed N 2 fixation in two out of the three varieties used in Romania. One variety, F 74-412, however, derived slightly higher amounts of N2 from fixation at 100kgN/ha rate than when fertilized with 20kgN/ha. In Greece, Chippewa, Williams and Amsoy-71 inoculated with a Nitragin inoculant fixed similar amounts of N 2 at both 20 and 100 kg N/ha fertilizer rates. However, when Chippewa and Williams were inoculated with another, locally-isolated Rhizobium strain, N2 fixation was substantially depressed at the higher N rate.