The study attempts to assess the present state of the resources and quality of water in small rivers that drain the area of the junction of two motorways, A1 and A2, being under construction nearby Łódź. In order to describe the physicochemical properties of surface waters in the area threatened with changes in the hydrological and hydrochemical regime, flow intensity and water reaction (pH), conductivity, oxygen content and temperature were measured in permanent cross-sections during two years (O₂ during one year) at 2-week intervals. The underground component of the outflow was also estimated. It was found that nearly all the rivers (except one) have quasi-natural regimes and the quality of water is high (class I and II). The seasonal pattern of water temperature variation can be treated as a basis for determining whether, and to what extent, the other characteristics of water in the rivers display a seasonal pattern of changes.

Investigations covering water in the Warta river between Oborniki and Skwierzyna in the years 1992/1993–2001/2002 revealed an unexpected decrease in the concentration and load of total nitrogen and main nitrogen forms in the lower stretch of the river, i.e. Kłosowice–Skwierzyna. The drop was seen in each year. During the study decade the nitrogen load carried by the river between Oborniki and Kłosowice (upper stretch) increased by 2181.4 Mg ^. year^-1 on average, whereas on the lower stretch it decreased by 4804 Mg ^. year^-1. The largest share of the load was contributed by organic nitrogen. The rate of decrease in the concentration of nitrogen compounds contained in the river water on the Kłosowice–Skwierzyna stretch was found to depend on the mean annual concentration of total nitrogen recorded in Kłosowice.

To define the degree to which the grounds in the vicinity of petrol stations in Kraków are polluted with lead, chromium, copper and zinc and with aliphatic and aromatic hydrocarbons, the levels of those heavy metals and hydrocarbons were determined in soil samples taken from the areas surrounding seven petrol stations located in the city. It was found that the Pb, Cr, Cu and Zn contents of soil varied considerably between the stations and at some points exceeded the natural values, but they were never beyond the limits established for industrial areas. The levels of aliphatic hydrocarbons exceeded the limits only at three petrol stations, whereas those of aromatic hydrocarbons were within the permissible range.

A well-stocked complex of isolation green around a motorway should have the highest possible density over the whole year. In order to achieve such a state as early as a few years after planting on former arable land, it is necessary to use a forecrop of fast-growing trees suitable for the initial stage of forest succession. When the forecrop reaches the stage of thicket, it is possible to introduce under its canopy another species which will form a multi-storey, well-stocked plant complex during the whole developmental period. With a proper selection of the species and a substantial proportion of wintergreen plants the further stages of succession will lead to the creation of a complex of expected physiognomy. The formation of such a complex of isolation green is only possible through introducing foreign species along with indigenous ones.

Research on roadside shrub communities in agricultural areas of the Szczecin Lowland showed their floristic and phytosociological differences resulting from the spatial distribution of the communities in relation to the road verge and confirmed that the roadside flora has a synanthropic character. The shrub communities were mostly composed of apophytes. The biological spectrum was dominated by hemicryptophytes and the main part of the phytocenoses was built of nanophanerophytes. The results demonstrated a stable floristic composition and persistence of roadside shrub communities and their important role in preserving the species diversity in the transformed agricultural landscape of the Szczecin Lowland.

Three-year field experiments carried out on a light soil in the Wrocław region provided the basis for investigating the effect of sprinkling irrigation and nitrogen fertilisation with varying rates on the protein and mineral component contents of the grain of brewing barley cv. Scarlett. The two factors caused significant differences in the protein yield and nitrogen content of grain but had no influence on the levels of other mineral components, such as phosphorus, potassium, calcium, magnesium and sodium. The protein yield and the nitrogen content were significantly lower in irrigated treatments than in non-irrigated ones, whereas rising the nitrogen rate increased both.

A field experiment conducted in the years 2002–2004 in Samotwór near Wrocław assessed the usefulness of three kinds of nitrogen fertilisers – CAN (27% of nitrogen), Norwegian saltpetre (15.5% N) and Puławy saltpetre (34% N) –in the cultivation of spring brewing barley cv. Scarlett on a light soil under sprinkling irrigation. The soil had average levels of phosphorus and magnesium and a high potassium content. The soil reaction (5.6–6.4) was too low for the needs of brewing barley. Under natural precipitation the yields of barley grain ranged from 34.06 dt ^. ha^-1 (2002) to 54.16 dt ^. ha^-1 (2003). Sprinkling irrigation, regardless of the kind of nitrogen fertiliser, caused a 7.5% increase in the grain yield. Among the fertilisers compared, CAN proved the best: its use led to the highest yields in non-irrigated treatments (45.71 dt ^. ha^-1) and the largest yield increase due to irrigation (8.3% on average). That fertiliser also brought about a significant rise in the number of ears per square metre.

Research conducted during 2002–2004 on a light soil in the Wrocław region investigated the effects of sprinkling irrigation and three kinds of nitrogen fertilisers – CAN, Norwegian salpetre and Puławy salpetre – on the levels of protein and mineral components in the grain of brewing barley cv. Scarlett (the nitrogen rate was 68 kg ^. ha^-1 irrespective of fertiliser). It was found that the protein content of barley grain depended to the greatest extent on the weather conditions that varied between the vegetation seasons of the study years. In sprinkled treatments, grain contained significantly smaller amounts of nitrogen, calcium and protein than in non-irrigated treatments. The kind of nitrogen fertiliser did not produce any significant differences in the nitrogen, phosphorus, calcium or magnesium contents. Barley grain from treatments fertilised with Puławy saltpetre had a significantly higher sodium level.