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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 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.

Climate warming increases the water needs of plants. The aim of this study was to estimate the water needs of grapevines in central Poland. Water needs were calculated using the crop coefficients method. Reference evapotranspiration was assessed by the Blaney–Criddle’s equation, modified for climate conditions in Poland. Crop coefficients were assumed according to the Doorenbos and Pruitt method. Water needs were calculated using the data from four meteorological stations. Rainfall deficit with the probability occurrence of normal years, medium dry years, and very dry years was determined by the Ostromęcki’s method. Water needs of grapevines during the average growing season were estimated at 438 mm. Upward time trend in the water needs both in the period of May–October and June–August was estimated. Temporal variability in the water needs was significant for all of the provinces. These changes were mainly impacted by a significant increasing tendency in mean air temperature and less by precipitation totals that did not show a clear changing tendency. Due to climate change, vineyards will require irrigation in the near future. The use of resource-efficient irrigation requires a precise estimate of the grapevines’ water needs. The study identified the water requirements for grapevines in central Poland.

Control drainage (CD) is a common practice implemented to control the water balance of drainage fields by increasing the amount of water retained in soil. Worldwide studies suggest that climate change can reduce the effectiveness of CD solutions, but no study of CD effects has been carried out in Polish conditions yet. In this study, the DRAINMOD (Wayne Skaggs, North Carolina State University, Raleigh, USA) computer simulation model was used to predict the effects of CD on the time horizons of 2021&ndash, 2050 (near future) and 2071&ndash, 2100 (far future) assuming the Representative Concentration Pathway (RCP) 4.5 emission scenario. The effectiveness of CD solutions is presented for a drainage network with spacing of 7 or 14 m. Additionally, different dates of blocking the outflow from the drainage network (1st and 15th of March and 1st and 15th of April) and different initial groundwater table conditions (0.4, 0.6, and 0.8 m) were assumed. All simulations for different variants were carried out for the same period, i.e. from 1st of March to 30th of September. The results of climate models indicated that in the area of central-western Poland in the near and far future there will be an increase in air temperatures by 1.02 and 1.97 C, respectively, and in precipitation by 5.98% and 10.15%, respectively. In addition, there will be a change in the structure of precipitation, especially with respect to the extension of rain-free periods and an increase in the amount of extreme daily precipitation. The effect of climate change will be a decrease in the mean groundwater table in the fields equipped with drainage systems from 2 to 5 cm. In addition, the number of days on which groundwater table will be above the level of the drainage network will decrease. For the drainage network with spacing of 7 m, the time of the groundwater table above the level of the drainage network will decrease by 5 and 7 days in the near and far future, respectively, while for the drainage network with spacing of 14 m, it will decrease by 4 and 7 days. Climate change will also reduce sub-surface outflow. Subsurface outflows will be smaller than those currently recorded on average by 11% and 17% and 12% and 18% for 7 m and 14 m spacing drainage networks, in the near and far future, respectively. The increase in rainfall intensity in the near and far future will result in a fivefold increase in surface outflow in comparison to the present situation. The simulations show that the greatest effectiveness of CD solutions will be achieved by starting the blocking of outflow from the drainage network on the 1st of March. The implementation of CD solutions since April in the near and far future will allow maintaining the groundwater table at the level presently observed for the conventional network (free drainage-FD).

Trends in groundwater level changes in small forest catchments located in Wielkopolska region were analysed on the basis on data collected for many years of groundwater levels observations. The observations were carried out from 2000 to 2010 hydrological year in Marianka Siemiańska and Laski forest district as well as in Puszcza Zielonka. The groundwater levels were measured in soil profiles located in different forest habitats: fresh, moist and swamp forest. Changes in groundwater level determined using the Mann-Kendall test were found to differ significantly between the catchment studied. Statistically insignificant decrease in groundwater levels was observed at all forest sites in the catchment area in Marianka Siemiańska forest district. In the catchment area of the Hutka watercourse the groundwater level showed a statistically significant decreasing tendency in Puszcza Zielonka in swamp and fresh mixed coniferous forest. It may indicate a decrease in water resources and implies the need of groundwater level monitoring. A statistically insignificant increase in groundwater level was observed in the wells in moist mixed broadleaved forest in the area of pond catchment in Laski forest district, this trend was interpreted as a result of the clearcutting made in this area.

The paper presents the results of the effects of control drainage (CD) on the groundwater table and subsurface outflow in Central Poland. The hydrologic model DRAINMOD was used to simulate soil water balance with drain spacing of 7 and 14 m, different initial groundwater Table 40, 60 and 80 cm b.s.l., and dates at the beginning of control drainage of 1 March, 15 March, 1 April, and 15 April. The CD restricts flow at the drain outlet to maintain a water table during the growing season. Simulations were made for the periods from March to September for the years 2014, 2017, and 2018, which were average, wet, and dry, respectively. The simulations showed a significant influence of the initial groundwater tables and date blocking the outflow from the drainage network on the obtained results. In the conditions of central Poland, the use of CD is rational only when it is started between 1 and 15 March. In this case, the groundwater table can be increased from 10 to 33 cm (7 m spacing) and from 10 to 41 cm (14 m spacing) in relation to the conventional system (free drainage&mdash, FD). In the case of blocking the outflow on 1 March, the reduction is about 80% on average in the period from March to September. With a delay in blocking the outflow, the impact of CDs decreases and ranges from 8% to 50%. Studies have shown that the proper use of the drainage network infrastructure complies with the idea of sustainable development, as it allows efficient water management, by reduction of the outflow and, thus, nitrates from agricultural areas. Furthermore, CD solutions can contribute to mitigating the effects of climate change on agriculture by reducing drought and flood risk.