The paper characterizes the status, trends and perspectives of irrigation in Poland after the reforms in agriculture and technology. Irrigation in Poland has supplemental character. It is used in short periods during the growing season and plays an important role in mitigating the effects of drought on crop production. Sub-irrigation from ditches is applied on permanent grasslands, sprin-kling – in field cultivation of arable crops, sprinkling and drip irrigation – in vegetable growing in open areas, micro-jets and drip irrigation systems – in orchards. Drip irrigation and micro-jets sys-tems are also applied in plant cultivation in greenhouses.

Under the economic conditions of Polish agriculture irrigation is often an unprofitable measure. The existing irrigation systems and facilities are only used to a small extent. After changes in the forms of ownership in agriculture, the large-area sprinkling systems were degraded. Small irrigation systems, mainly drip irrigation and micro-sprinkler irrigation, have recently become more common in private farms. Sub-irrigation systems are largely degraded and used only to a small extent if at all. In order to use these systems more effectively, it is necessary to reconstruct and modernize them. In many cases the factor preventing the use of irrigation systems is the deficit of water of required qual-ity and its availability. Besides unfavourable economic conditions, it is one of the main limitations in the development of irrigation in Poland.

Uncertainties as to how the climate will change and how it will influence the necessities and trends of irrigation development lead to a number of serious questions to be answered in the near future. How irrigation and water systems will have to adapt to climate changes is a challenge that planners, designers and O&M services will have to cope with.

It is widely accepted that air temperature in Poland will increase of 2–4°C, however a total yearly precipitation will not vary yet its pattern during the year may change towards higher in winter and lower in summer. Evapotranspiration and crop water demand may rise due to both an increase in temperature and duration of crop growth cycles.

Three main factors are expected to exert an accelerating influence on the development of irrigation: increased frequency and intensity of droughts and long-lasting precipitation-free periods with the high insolation and high air temperatures resulting from climate change; the intensification of agricultural production (e.g. in horticulture, orchards, seed crops), being forced by both domestic and European free-market competition; the necessity of reaching high level of quality for the majority of agricultural products.

To mitigate negative effects of climate change and extreme events, appropriate adaptation methods and adaptation strategies should be developed and implemented in existing irrigation and water control systems. A number of technological and organisational steps should be taken to improve operation, management, administration and decision making processes.

Water is a sensitive and limited resource, mainly in intensively used agricultural areas in Austria, where groundwater is used as drinking water as well as for irrigation purposes. In order to guarantee a sustainable use of irrigation water, soil water measurement devices can be used to opti-mise irrigation, which means that controlling the soil water content in the entire root system may prevent water stress due to water deficiency on the one hand, and over wetting on the other hand. Furthermore, losses of nutrients due to leaching can be avoided. Several research studies on that topic were initiated during the last few years. The soil water status on selected fields planted with different crops (onions, carrots, sugar beets, sweet maize, zucchini) was monitored continuously by FDR (Fre-quency Domain Reflectometry) soil water measurement devices. Sensors in different depths measure the plant water uptake in the root zone under standard irrigation practices on different sites and dif-ferent soils, respectively. The deepest sensor is installed to avoid deep percolation caused by over irrigation. By means of these data, irrigation could be regulated based on the actual plant water re-quirements to keep the soil water content within an ideal range for crop development.

The irrigation system control is identified as a complex hierarchical process of stochastic nature, at the head of which the uncertainties, caused by random variations of meteorological factors (climate) and diversion capacity regime from irrigation canals, were laid.

Under such conditions application of the determinate methods for irrigation system control regarding the effectiveness surrenders to the formalistic and empirical methods.

The most appropriate method is the developed by us, method of preventive control.

As a result of retrospective analysis, to each system status, for example, diversion capacity, it is fixed the factors which lead to its changes, for example, rain layer or total evaporation. To every consequence “factor – system status” it is fixed the indicator and it is determined the probability of its exceeding in retrospective series.

The control is in following of such indicator dynamics, forecasting of the most probably changes within system status and adjustment of the water delivery regime to canal reaches with diversion capacity regime from irrigation canals by means of standard preventive graphical chats of water flow control within hydraulic structures and pumping stations.

Use of such control method allows to minimize the uncertainty influence, also it does not require the major modifications in the design and engineering infrastructure.

As an exception can be the measures, directed to the increase of self-regulating qualities of irrigation systems, namely the ability of on-line water volume control, which is regulated in the idle capacities, provided in canal beds or special reservoirs.

The example of such decision in practice is the Kakhovskaya irrigation system in the South of Ukraine. The use factor of water resources on this system reaches 0.85, the technological discharge water does not exceed 7%, the deficit of productive moisture reserve in soil at the end of interirrigation period does not exceed 20% and all these data were obtained under adverse weather conditions.

CropSyst (Cropping Systems Simulation) is used as an analytic tool for studying irrigation water management to increase wheat productivity. Therefore, two field experiments were conducted to 1) calibrate CropSyst model for wheat grown under sprinkler and drip irrigation systems, 2) to use the simulation results to analyse the relationship between applied irrigation amount and the resulted yield and 3) to simulate the effect of saving irrigation water on wheat yield. Drip irrigation system in three treatments (100%, 75% and 50% of crop evapotranspiration – ETc) and under sprinkler irrigation system in five treatments (100%, 80%, 60%, 40%, and 20% of ETc) were imposed on these experiments. Results using CropSyst calibration revealed-that results of using CropSyst calibration revealed that the model was able to predict wheat grain and biological yield, with high degree of accuracy. Using 100% ETc under drip system resulted in very low water stress index (WSI = 0.008), whereas using 100% ETc sprinkler system resulted in WSI = 0.1, which proved that application of 100% ETc enough to ensure high yield. The rest of deficit irrigation treatments resulted in high yield losses. Simulation of application of 90% ETc not only reduced yield losses to either irrigation system, but also increased land and water productivity. Thus, it can be recommended to apply irrigation water to wheat equal to 90% ETc to save on the applied water and increase water productivity.

The European Water Framework Directive can have enormous consequences for agricul-ture in the Netherlands. In parts of the country agriculture should be taken out of production because the nutrient loads to the surface water system are far too high. This doom scenario is of course unde-sired and a number of source-specific and effect-specific measures are necessary. The fate of nutri-ents in the soil is strongly interrelated with its hydrology. Directly, because nutrients are transported by water and the distribution of the residence time of drainage water is a good measure for the time behaviour of the nutrient loads to the surface water system. Longer residence time in the soil means more of nutrients applied by farmers but also a longer recovery period, after applying source-specific measures. In this paper three promising effect-specific hydrological measures are described buffer strips, retention strips, and controlled drainage.

Wetlands play a significant role in agricultural landscape. They are the areas of exception-ally great natural values able to regulate water cycling in river catchments. In many cases they are the basic food source for bred animals.

Large areas of wetlands (c. 4 million ha) have been drained for agricultural purposes in Poland. Nevertheless, there are still numerous natural (or close to natural) wetlands, part of which is protected in nature reserves or national parks.

Having in mind the transformation of agriculture and the need of protecting water resources and natural environment, it is necessary to regulate the principles of utilisation and management of re-claimed wetlands. Water management should be adjusted to the type of an area and to environmental requirements. Regardless of the type and intensity of agricultural use of wetlands one has to aim at limiting rapid outflow of spring thaw and rainfall waters which means the reconstruction and increas-ing of natural retention capacity of the river catchment. It is necessary to provide an appropriate num-ber of water lifting facilities and their proper exploitation in land reclamation objects.

It is as well necessary to create appropriate organizational, legal and financial conditions stimu-lating actions to improve water balance and wetland protection.

The paper deals with calibration of the simulation models of hydraulic part of an irrigation project. Calibrated simulation model can be used in design, reconstruction, enlargement or maintenance of the pressurized irrigation systems. Computer model of the water distribution system is a valuable tool which can assist engineers and planners in analyzing the hydraulic performance of water delivery systems. Calibration of the water distribution model consists in comparison of pressures and flows predicted with observed pressures and flows for known operating conditions (i.e., pump operation, tank levels, pressure-reducing valve settings), and adjustment of the input data for the model to improve agreement between observed and predicted values. In practice, given a set or sets of measured state variables, engineers apply trial and error techniques with their judgment to vary the parameters and accomplish this task. Trial and error techniques are tedious do not guarantee reasonable results. The paper introduces the methodology of determination of calibrated parameters automatically. Described methodology of calibration is based on optimizing procedures using the harmony search approach.

The study took place between 2012 and 2014 in Falenty near Warsaw, Poland, as part of a long-term scientific experi-ment (first began in 1987) using the randomized block method. All blocks were irrigated until 2008. In 2009 each block was divided into two areas: irrigated and non-irrigated. The study involved four levels of inorganic nitrogen fertilizer and two levels of mixed inorganic and organic fertilizer in the form of fermented cattle urine. The soil in all experimental plots was characterized by low levels of zinc, ranging from 7.6 to 16.7 mg Zn∙kg–1 dry matter. Much lower Zn content in both soil layers of all irrigated plots was associated with increased yields on these plots, regardless of the level and form of ferti-lizer. The content of Zn in soil and sward in 2014 year was significantly lower compared in 2012. Inadequate levels of zinc for ruminant nutrition were observed in the sward from all plots (15.4–28.8 mg∙kg–1 dry matter). The higher content of zinc was found in sward harvested from the plot, which was not fertilized with phosphorus. The long-term inorganic and fer-mented urine fertilization resulted in very low zinc content in the soil and meadow sward.

The aim of this study was an assessment of feasibility of conversion of sewage holding (SH) tanks to rainwater harvesting (RWH) tanks in Poland. Such a conversion may partly solve the problem of water scarcity for irrigation of plants in individual small gardens and reduce tap water consumption. Seven methods of RWH tanks sizing were applied to an example of a small harvesting system of the roof area equal to the garden irrigation area of 100 m² for three different irrigation doses. A new criterion was introduced to optimize the tank capacity. Economic optimization was provided for new RWH tanks and for the tanks adapted from abandoned SH tanks. Results obtained for a system sited in west-central Poland in an average year have shown that design capacity of RWH tanks varied markedly between sizing methods. The conversion of SH tanks to RWH tanks is profitable, especially for irrigation due to scarcity of water in relatively dry west-central regions. Conversion of individual SH tanks in a good technical state to RWH tanks is relatively simple and cheap. The potential increase in storage volume due to the conversion of individual SH tanks to RWH tanks could reach all over Poland 215–350 dam³ per year, and individually can save up to 18–25% of total annual water use.

CropSyst model can be used as irrigation water management tool to increase wheat productivity with poor quality water. The objective of this study was to calibrate CropSyst model for wheat irrigated with fresh and agricultural drainage water. To do so, three field experiments were conducted during three successive seasons in Nubaria Agricultural Research Station, Egypt representing the newly reclaimed calcareous soils. In the first season the treatments were 100% crop evapotranspiration (ETc) of fresh water (FW) and 100% ETc of agricultural drainage water (DW), while in the second and the third seasons, the treatments were 100% ETc of FW, 100% ETc of DW, 120% ETc of DW and 130% ETc of DW. From these results one can concluded that deducting 5% of the applied water to all treatments reduced yield by 3, 5 and 7% in the first, second and third growing season, respectively as a result of heat stress existed in the 2nd and 3rd seasons during reproductive phase. Furthermore, deducting 5% of the applied water from all treatments in the vegetative phase only resulted in lower yield losses. Thus, using CropSyst model could guide us to when we could reduce the applied irrigation water to wheat to avoid high yield losses.

Polish water resources depend on precipitations, which are variable in time and space. In dry years the water balance is negative in central parts of Poland but sudden thaws and downfalls may result in periodical water excess and dangerous floods almost in the entire country. The retention capacity of artificial reservoirs in Poland permits to store only 6% of the average annual runoff, which is commonly considered insufficient. Another method to increase retention is soil water con-trol. About fifty percent of soils in Poland consist of light and very light sandy soils with low water capacity. Loams and organogenic soils cover approximately 25% and 8.5% area of the country, re-spectively. Almost half of agricultural lands (48%) have relatively good water conditions, but the rest requires soil water control measures. An increase of the soil water content could be achieved by changes of soil properties, water table control and soil water management. Modernization and recon-struction of drainage and irrigation systems, which were built mainly in the period 1960–1980, is needed.

The abundance of water has certainly been a very important resource for the development of the Po Valley and has necessitated, more than once, interventions of regulation and drainage that have contributed strongly to imprint a particular conformation on the land. Already in Roman times there were numerous projects of canalisation and intense and diligent commitment to the maintenance of the canals, used for navigation, for irrigation and for the working of the mills. The need to control the excessive amount of water present was the beginning of the exploitation of this great font of richness that was constantly maintained in subsequent eras. In the early Middle Ages, despite the conditions of political instability and great economic and social difficulty, the function of the canals continued to be of great importance, also because the paths of river communication often substituted land roads, then left abandoned. After the 11th century A.D. the resumption of agricultural activity was conducive to the intense task of land reclamation of the Lombardian countryside and of commitment by the cities to amplify their waterways with the construction of new canals and the improvement of those already existing. The example given by Milan, a city lacking a natural river, that equipped itself with a dense network of canal, used in various ambits of the city life (defence, hygiene, agriculture, transport, milling systems) and for connections with the surrounding territory, can be considered as emblematic. In the surrounding countryside, the activity of the Cistercian monks of Chiaravalle represents one of the situations more indicative of how land reclamation and waterways contributed fundamentally to the organisation of the territory over the span of the ages.