The purpose of this research was to determine the water needs and results of drip irrigation of mid-early potato cultivar Courage. Studies were carried out in central Poland in 2011–2013 on very light soil. The experiment was designed as two-factorial trials with four replications. The first factor was drip irrigation: O = control (without irrigation), D = drip irrigation. The second factor was the nitrogen fertilization method: P = broadcasting, F = drip fertigation. Nitrogen fertilization was 120 kg N ha⁻¹ on each plot. Crop coefficients for irrigation period were 0.4 in June and 0.6 in July and August. According to calculations based on the crop coefficients and correction coefficients acc. Hargreaves^DA model the water requirement of potato for June–August was 202 mm. Drip irrigation increased the marketable tuber yield by 55%. Irrigation water use efficiency increased from 257 kg ha⁻¹ mm⁻¹ in D + P to 264 kg ha⁻¹ mm⁻¹ in D + F. The productivity of 1 kg of nitrogen fertilization was 189 kg ha⁻¹ in control non-irrigated plots and 321 kg ha⁻¹ in drip-irrigated plots, and it rose up to 337 kg ha⁻¹ when fertilization was applied by fertigation.

Most species of Cucurbitaceae respond favorably to irrigation, especially when combined with fertilizers. The effect of drip irrigation combined with nitrogen fertigation in melon grown on a very light soil in Central Poland, during 2013–2015, was evaluated. The field experimental design was a split-plot with four replications. Two factors were studied: (1) irrigation treatments applied in two combinations—drip irrigation + broadcast nitrogen fertilization (control), and drip irrigation + fertigation with nitrogen; (2) two cultivars—Melba and Seledyn. The total marketable yield of fruits, weight of a single fruit, and the concentration of dry matter, total sugars, monosaccharides, ascorbic acid, total carotenoids, and polyphenols were evaluated. Tested factors presented a significant effect both on the yield and nutritive value characteristics. Drip irrigation combined with nitrogen fertigation, comparing to the control, notably improved yields and nutritional value of fruits. Seledyn produced better yields than Melba. This study shows that on very light soil, with low water and nutrient retention capacity, melon should be drip-irrigated and nitrogen-fertigated to obtain the best cultivation results.

The aim of the research has been to assay the contents of Zn, Cu, Mn, Fe, and Pb in soil and in the organs of wild Thymus serpyllum L. acquired from three natural habitats from the Kuyavia-Pomerania Province (Poland) not exposed to contamination with metals. As compared with the contents of the geochemical background of the soils in the region and the value of enrichment factor (EF), there was noted a considerable content of Pb in the soil from two locations. The Pb content in plant tissues in one of the three locations was higher than the admissible content specified by the World Health Organization WHO (above 10 mg kg⁻¹ d.w.). As for the Zn content, only the plants from the locations with the relatively youngest phytocenosis met the conditions for herbs to be used for phytotherapy. The Zn content in the dry weight of the plants collected from the other two locations exceeded 50 mg kg⁻¹. The risk of an elevated content of Zn and Pb in the plants makes it necessary to monitor the soil environment and to limit the collection of the plants from natural habitats, as well as to encourage the collection from controlled habitats.

The aim of this study was to verify the response of 13 American asparagus cultivars cultivated for green spear on surface postharvest drip irrigation. Irrigation, used to compensate for periodic deficiencies in precipitation, allows for high- and good-quality crops for many species. The field experiment was carried out in 2006–2008 on a very light sandy soil in central Europe (Poland). Irrigation treatments were applied using the tensiometer indications. Water requirements of asparagus were calculated on the base of reference evapotranspiration and crop coefficients. The following evaluations were made: Height, diameter, and number of summer stalks, as well marketable yield, weight, and number of consumption green spears. Drip irrigation applied for 2 years (2006–2007) in the postharvest period had a positive effect on all studied traits in both summer stalks and green spears in 2007–2008. A significant increase in the height, number, and diameter of summer stalks, as well an increase in the marketable yield, weight, and number of green spears was observed for most of the cultivars. In general, postharvest drip irrigation of asparagus cultivated in very light sandy soil significantly contributes to the increase in productivity of American cultivars of this species.

The effect of nitrogen fertigation of two watermelon cultivars grown on the very light soil in the central part of Poland, during 2012–2014, was evaluated. The field experimental design was a split-plot with four replications. The main plot was the drip fertigation with nitrogen applied in two combinations: drip irrigation + broadcasted nitrogen fertilization (DI) used as a control, and drip irrigation + fertigation with nitrogen (DF); where, two cultivars: Bingo and Sugar Baby were used as a split-plot. The phosphorus and potassium fertilizers were applied pre plant in the spring, whereas, three rates of 40 kg ha⁻¹ of nitrogen fertilizer were applied during the growing season. The fertigation was performed using a proportional mixing dispenser. The ripened fruits were harvested progressively as they mature. The marketable fruit yield, the single fruit weight and the number of fruits per plant, were evaluated. Tested factors presented a significant effect in the yield characteristics, further the interaction among the factors was important. DF, comparing to DI, notably improved fruit traits. Bingo cultivar had higher yield than Sugar Baby, but Sugar Baby cultivar produced more fruits than the Bingo under the DF treatment. This study provides the evidence that on a very light soil with low water and nutrients retention capacity the performance of watermelon can be optimized when nitrogen is applied directly through drip irrigation.

Willows are one of the plants which can be used to produce biomass for energy purposes. Biomass production is classified as a renewable energy source. Increasing the share of renewable sources is one of the priority actions for European Union countries due to the need to reduce greenhouse gas emissions. To achieve the best possible growth of the willow and increase its biomass for fuel, it is crucial to provide optimal water conditions for its growth. The aim of the study was to determine the water requirements of willows under the conditions of the western Polish climate and to verify whether this area is potentially favourable for willow cultivation. The novelty of this paper lies in its multi-year climatic analysis in the context of willow water needs for the area of three voivodships: Lubusz, Lower Silesian, and West Pomeranian. This is one of the few willow water-needs analyses for this region which considers the potential for widespread willow cultivation and biomass production in western Poland. Reference evapotranspiration (ETo) was determined by the Blaney-Criddle equation and then, using plant coefficients, water needs for willow were determined. Calculations were carried out for the growing season lasting from 21 May to 31 October. The estimated water needs during the vegetation season amounted on average to 408 mm for the West Pomeranian Voivodeship, 405 mm for the Lubusz Voivodeship, and 402 mm for the Lower Silesian Voivodeship. The conducted analysis of variance (ANOVA) showed that these needs do not differ significantly between the voivodeships. Therefore, it can be concluded that the water requirements of willows in western Poland do not differ significantly, and the whole region shows similar water conditions for willow cultivation. Furthermore, it was found that water needs are increasing from decade to decade, making rational water management necessary. This is particularly important in countries with limited water resources, such as Poland. Correctly determining the water requirements of willow and applying them to the cultivation of this plant should increase the biomass obtained. With appropriate management, willow cultivation in Poland can provide an alternative energy source to coal.