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-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.Sustainability 2019, 11, 4201 2 of 18 water users to be affected by the consequences of climate change in different way [5]. Consequently, this will lead to exacerbated competition among water users and sectors [6].One of the main challenges for sustainable development is the adaptation of national economies to climate change. Most often, climate change adaptation projects in Poland are carried out in cities and areas subject to urban sprawl [7][8][9]. Agriculture is a key sector for food supply, and its functioning depends largely on access to water. It is, therefore, necessary to take various actions to protect this sector of national economies against climate change. The most frequently asked question is whether and to what extent it is possible to take action in the adaptation of agriculture to climate change while maintaining high environmental standards and accounting for the acceptance of society and economic balance.The greatest scope for the mitigation of the effects of climate change is in improving adaptive capacity and responding to changes in water demands [10]. Agricultural subsurface drainage, popularly known as tile drainage, is an essential water management practice in agricultural regions with seasonal high groundwater tables [11]. Around 193.9 × 10 6 ha of arable land, and permanent crops have been drained around the world. In 30 countries, th...

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 2021–2050 (near future) and 2071–2100 (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).

The aim of this study was to examine the influence of various types and levels of effective microorganism (EM) applications on scarlet sage. For this purpose, EMs were applied at the following three concentrations: 1:10, 1:50, and 1:100. Moreover, two types of treatments (spraying and watering) and a combination of the two were also examined. Photosynthetic intensity was analyzed, including the net photosynthesis rate (PN), stomatal conductance (gS), and intercellular CO2 concentration (Ci). Additionally, chlorophyll a, b, and a + b, and the chlorophyll b/a ratio were analyzed. The microbial content in the medium and soil enzyme activity were also evaluated to examine the effect of EMs on soil biological properties. The investigations revealed a high positive effect of EMs on the photosynthetic activity of most EM combinations compared with the control. The greatest positive effect was noted for the highest EM concentration application for both types of treatments. There was no such influence on soil activity. An increase was noted only in the number of fungi and dehydrogenase activity, while the rest of the soil biological status parameters revealed significant variability, and mostly small or no effects were recorded.

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.

ha jest w 100% zlewnią leśną. Natomiast zlewnia oczka nr 6, o powierzchni około 37 ha, jest w 40% zlewnią leśną a pozostałe 60% obszaru badanej zlewni stanowią grunty orne. Analizowane w pracy oczka nr 1 i 6 o łagodnych skarpach, mają charakter naturalnych oczek wytopiskowych. Powierzchnia oczka nr 1 wynosi 0,13 ha a oczka nr 6 0,35 ha, przy średnich głębokościach wynoszących odpowiednio 1,0 m i 1,4 m. Przeprowadzone badania potwierdziły, że zmiany stanów i związanych z nimi zapasów wody w śródleśnych oczkach wodnych nr 1 i 6 w dużej mierze uzależnione był również, poza przebiegiem warunków meteorologicznych, od ich cech morfometrycznych. Badania wykazały także silną więź hydrauliczną polegającą na okresowym odpływie wód z oczek do gleb przyległych siedlisk i odwrotnie. Obliczone współczynniki korelacji, dla związków stanów wód w oczkach ze stanami wód gruntowych przyległych siedlisk w omawianych latach hydrologicznych osiągały wartości od 0,43 do 0,96 i zależności te były w większości istotne na poziomie α=0,01.

No abstract

According to forests act [Dziennik Ustaw… 2014] the statutory duty of the National Forest Holding "State Forests" is carrying out sustainable forest management aimed at preserving sustainability of forests and enhancement of forest resources and the continuity of their multilateral use. According to the data from the Report on the condition of forests in Poland in 2013 [Raport… 2014], 48.8% of the area is forested with a dominant economic function. Therefore, due to economic nature of forests, there is a need to create clearcuttings. Clearcuttings, which are artificial disturbances in the forest environment are single cut downs, ie. a complete cut down of all trees of mature tree stand, intended to be removed during its renewal [Jaszczak 1999]. Creating of clearcutting changes abiotic conditions, availability of nutrients, by definition disrupts the functioning of ecosystems, groups or population [Sławska 2006, Sławski 2006]. On the surface covered by clearcutting may occur many, sometimes very abrupt changes. As a result of the relatively rapid reduction of biomass in a large

STRESZCZENIE W pracy przedstawiono wyniki wieloletnich badań prowadzonych na obszarze środkowej części kompleksu leśnego Puszcza Zielonka, dotyczących możliwości retencjonowania wody w śródleśnych oczkach wodnych i mokradłach. Obiektem badań była zlewnia cieku Trojanka, od źródła do przekroju Jezioro Zielonka, położona w centralnej części Wielkopolski. Zlewnia o powierzchni 223 ha była w charakterze leśnym W pracy dokonano analizy przebiegu warunków meteorologicznych w trzech latach hydrologicznych charakteryzujących rok mokry (1987), suchy (2003) i średni (2009) na tle wielolecia 1986-2009. W analizowanych latach obliczono pojemność retencyjną poszczególnych mokradeł oraz dokonano oceny możliwości retencjonowania wody w zlewni cieku Trojanka. Przeprowadzone badania potwierdziły istotny wpływ warunków meteorologicznych na ilość magazynowanej wody. Przy łącznej powierzchni mokradeł i bagien wynoszącej 8,58 ha i opadzie z wielolecia na poziomie 555 mm obliczona pojemność zgromadzonej w nich wody wyniosła 15 852 m 3. W roku mokrym (1987), przy opadzie wyższym o 100 mm w stosunku do średniej z wielolecia odnotowano 18 procentowy wzrost ilości zmagazynowanej wody, natomiast w roku suchym (2003), przy opadzie niższym od średniej o 208 mm odnotowano znaczący 62% spadek retencjonowanej wody w mokradłach. Słowa kluczowe: retencja, mokradła, mała zlewnia leśna.