Condition Assessment of Subsurface Drained Areas and Investigation of their Operational Efficiency by Field Inspection and Remote Sensing Methods

The extreme weather events highlight the need to develop action concepts to maintain agricultural production security in the future. Hydrological extremes can occur within a year in the form of surplus water (i.e. inland excess water), water scarcity or even drought. These adverse effects are influenced, inhibited and also facilitated by human activity. Previously, complex amelioration interventions, including subsurface drainage, aimed to improve the productivity of agricultural areas with unfavourable water management properties. The current efficiency of the subsurface drain networks in the regulation of groundwater level or soil moisture content can be questioned from several aspects. After the end of the socialist era (after 1990s), lack of maintenance and operation tasks have become typical, and are still a problem today in Hungary. Unfortunately, there is no exact national cadastre on the tile drained areas, and data is only available to a limited extent in the original amelioration plan documentations. In the present study, we aimed to reveal the possibilities of delineating the subsurface drained areas, and to develop a new method of condition assessment. Three tile drained study sites were selected on the Great Hungarian Plain in Central Europe. Our field investigations revealed the typical problems of the drained areas: (1) excessive vegetation of the receiving channels; (2) inadequate condition of the receiving main channel bed; (3) soil compaction in multiple layers above the drainage network; and (4) poor condition of outlets of the drain pipes. The developed methodology enabled us to evaluate the soil and the surface/subsurface water of the tile drained areas, and the technical condition of the drains. The necessary action plans or treatments were also outlined to replace the unused drain networks into use. Based on the scientific literature, we also sketched the target conditions and technological solutions that are required for the installation of new drains. The organization of the derived data into a GIS database could serve as a basis for the development of a cadastre of the tile drained areas based on a regional approach

Condition assessment of subsurface drained areas and investigation of their operational efficiency by field inspection and remote sensing methods

The extreme weather events highlight the need to develop action concepts to maintain agricultural production security in the future. Hydrological extremes can occur within a year in the form of surplus water (i.e. inland excess water), water scarcity or even drought. These adverse effects are influenced, inhibited and also facilitated by human activity. Previously, complex amelioration interventions, including subsurface drainage, aimed to improve the productivity of agricultural areas with unfavourable water management properties. The current efficiency of the subsurface drain networks in the regulation of groundwater level or soil moisture content can be questioned from several aspects. After the end of the socialist era (after 1990s), lack of maintenance and operation tasks have become typical, and are still a problem today in Hungary. Unfortunately, there is no exact national cadastre on the tile drained areas, and data is only available to a limited extent in the original amelioration plan documentations. In the present study, we aimed to reveal the possibilities of delineating the subsurface drained areas, and to develop a new method of condition assessment. Three tile drained study sites were selected on the Great Hungarian Plain in Central Europe. Our field investigations revealed the typical problems of the drained areas: (1) excessive vegetation of the receiving channels; (2) inadequate condition of the receiving main channel bed; (3) soil compaction in multiple layers above the drainage network; and (4) poor condition of outlets of the drain pipes. The developed methodology enabled us to evaluate the soil and the surface/subsurface water of the tile drained areas, and the technical condition of the drains. The necessary action plans or treatments were also outlined to replace the unused drain networks into use. Based on the scientific literature, we also sketched the target conditions and technological solutions that are required for the installation of new drains. The organization of the derived data into a GIS database could serve as a basis for the development of a cadastre of the tile drained areas based on a regional approach

Calculation nitrogen and sodium budget from lysimeter-grown shortrotation willow coppice experiment

Alternative water resources utilization should take priority over the conventional irrigation water resources (surface and subsurface waters) in the future in Hungary as well, similarly to the global trends because of the climate change impacts. However because of the environmental risks (e.g. nitrate leaching and soil salinization) the reuse of the wastewater require sustainable practices hence the farmers and researchers are responsible for development soil management practices and irrigation principles. Aim of our study was to determine the impact of a wastewater originated from an African intensive catfish farm on the nitrogen budget of the soil-water-plant system in order to evaluate the nitrogen substitution effect and the risk of the nitrate leaching. On the other hand, the aim of the study was to calculate also sodium budget to assess the risk of the sodicity regard to the high sodium concentration of the wastewater. The experiment was conducted at the National Agricultural Research and Innovation Centre (NAIK), Research Institute of Irrigation and Water Management (OVKI) in Szarvas, Hungary. The experiment was set up in the NAIK ÖVKI Lysimeter Station in 2014 with energy willow. During the study (between 03.07.2015 and 21.04.2017) irrigation water quality, rainwater quality, willow N and Na uptake by stems and N and Na leaching was measured. Nitrogen and sodium budget were calculated for two years (2015, 2016) from these data. According to our results the wastewater had high nitrogen content what was able to increase the nitrogen amount in the examined budget however without supplementary fertilizer it could not able to balance the budget only just at W60 treatment (irrigation with wastewater: N concentration 22,7 mg/l). The wastewater had high environmental risk as soil sodicity according to results of the sodium budget

Macro-, mesoelement and sodium content of plant parts of energy willows irrigated with effluent water of agricultural origin

Irrigation of recycled water can be considered as an element of integrated water management, in which the nutrients in the water are used and decomposed by natural processes, while water retention is realized at the local level. In our study, we used the effluent of an intensive African catfish farm for irrigation. The farm uses thermal water for fish farming, which is characterized by a high sodium content. At the same time, the effluent is rich in organic matter and minerals. The planting of the willow plants in the study area, which is close to 3 ha, took place in the spring of 2014 with a variety candidate 'Naperti'. During the experiment, seven treatments were set up, of which one was non-irrigated, three were irrigated with the water of the Körös oxbow lake and three were irrigated with the effluent water. Three doses of irrigation water (15, 30, 60 mm) were applied to the one-week irrigation intervals with a microspray irrigation system. At the end of the growing season, samples of the plant parts (leaf, stem, root) were collected, during which mineral element analysis was performed with special regard to nitrogen, phosphorus, potassium, calcium, magnesium and sodium levels. The results of the study showed a significant difference in macroelements only for nitrogen for all plant parts. However, there was no significant difference in case of the mesoelements. In the case of sodium, compared to the leaf and stem plant samples, the root part accumulated a significant amount of salt, especially in the samples irrigated with 30 mm effluent water, where the Na content reached 521 mg kg-1

Használt termálvíz mezőgazdasági elhelyezésének (öntözés) hatása a talaj kicserélhető nátrium tartalmára és az összes oldott sótartalmára

Hazánkban a szélsőséges vízháztartási helyzetek fokozódásával a változó környezeti feltételekhez való alkalmazkodás megköveteli az aktuális mezőgazdasági gyakorlat módosítását az öntözés területén is. Az adaptáció egyik fontos eleme lehet az öntözéses gazdálkodási formák kiszélesítése, a víz- és energiatakarékos öntözési módok és módszerek előtérbe helyezése és nem utolsó sorban a használt vizek (szennyvizek, hulladékvizek, elfolyóvizek stb.), mint alternatív vízforrások öntözéses hasznosítása. Kísérletünkben egy intenzív afrikai harcsa-nevelő telepről származó használt termálvizet és Körös vizet használtunk fel energiafűz öntözésére egyéves liziméteres kísérletben. Az öntözéses kísérlet a Nemzeti Agrárkutatási és Innovációs Központ (NAIK) Öntözési és Vízgazdálkodási Önálló Kutatási Osztály (ÖVKI) szarvasi Liziméter Telepén valósult meg. A kísérletben 82-es fűz klón nyolcféle öntözéses kezelését alkalmaztuk. Eredményeink szerint a használt termálvíz minősége miatt öntözésre csak korlátozottan használható, mivel a szikesedésért leginkább felelős kémiai paraméterek (EC, SAR, nátriumszázalék és szódaegyenérték) értékei magasak. A vízminősége miatt (Körös víz felhasználásával) hígítással és gipsz javítóanyag hozzáadásával egy harmadik víztípust hoztunk létre (HG). A talaj kicserélhető kation tartalmában bekövetkező változásokat vizsgálva a használt termálvíz kiöntözése mellett a kicserélhető nátrium felhalmozódását mértünk valamennyi öntözési norma esetén. A hígított+kezelt öntözővíz (HG) mellett a talajban szignifikáns változás egy kicserélhető kation esetében sem történt. Körös víz öntözése mellett 15 és 30 mm öntözési norma esetén a hígított+kezelt vízhez hasonlóan jelentős változás nem történt, ugyanakkor a 60 mm-es öntözési norma mellett a nátriumtartalomban szignifikáns csökkenés volt kimutatható, amely a kilúgzásnak köszönhető. Az öntözetlen kezelésben a kicserélhető kalcium tartalom csökkenése mellett a magnéziumok mennyisége növekedett meg a talajkolloidok felületén, amely következtetésünk szerint természetes szikesedési folyamatok következménye. A talaj összes oldott sótartalma 0-40 cm mélységben a használt termálvizes öntözés után (60 mm öntözési norma) szignifikánsan különbözött a Körös vízzel öntözött kezelésekben mért értékektől, ugyanakkor a kezelt víz (HG) felhasználása mellett a talaj összes oldott sótartalma a Körös vízzel öntözött kezelésekben mért értékekhez hasonlóan változott és nem haladta meg a 0,05%-ot. A felhasznált öntözővizek talajra gyakorolt hatásának teljes körű értékeléséhez további talajvizsgálatokat tartunk szükségesnek, valamint a hosszú távú előrejelzések miatt a kísérletet folytatjuk több éven keresztül. Mindazonáltal megállapítható, hogy az elvégzett kísérletünk eddigi szakaszában az intenzív afrikai harcsanevelő telepről származó használt termálvíz jó minőségű vízzel való keverése és gipsz hozzáadása után felhasználható a talajvédelem szempontjából fenntartható módon, szolonyecesedés és sófelhalmozódás nélkül. | Because of the increasing frequency of extreme hydrological events in Hungary, conventional agricultural practices need to be modified in order to adapt to changing environmental factors. The development of new irrigation management practices, the use of water- and energy-saving methods and the reutilization of wastewater (agricultural effluents, treated wastewater, etc.) could be important elements in this adaptation. Used geothermal water (so called effluent water) from an intensive African catfish farm, water from the River Körös and improved effluent water were used in a lysimeter experiment for the irrigation of energy willow. The experiments were conducted at the Research Department of Irrigation and Water Management (OVKI) of the National Agricultural Research and Innovation Centre (NAIK) in Szarvas, Hungary. Seven irrigation treatments and one rain-fed control were applied in four replications during the 2015 vegetation period. The results demonstrated that the use of effluent water is limited by high values of the chemical properties responsible for sodification (EC, SAR, sodium content and bicarbonate toxicity,). For this reason, an improved form of effluent water produced by dilution and the addition of gypsum was also used for irrigation. Tests on changes in the exchangeable cation content of the soil showed that irrigation with effluent water led to the accumulation of exchangeable sodium at all the irrigation rates, while no significant changes were observed for any exchangeable cations in the case of diluted, treated effluent water. When water from the River Körös was used for irrigation no change in this parameter was recorded at irrigation rates of 15 or 30 mm, but the 60 mm irrigation rate resulted in a significant decline in the sodium content, associated with leaching. In the non-irrigated treatment a decrease in the exchangeable calcium content was accompanied by an increase in the quantity of magnesium on the surface of soil colloids, which could probably be attributed to natural sodification processes. After a year of irrigation with effluent water (at the 60 mm irrigation rate) the total dissolved salt content of the soil at a depth of 0-40 cm differed significantly from the values recorded in treatments given river water, but when the diluted, treated effluent water was applied, the total dissolved salt content in the soil was similar to that in the river water treatment and did not exceed 0.05%. Further soil analyses will be required to gain a better understanding of the effect of these irrigation sources on the soil, and the experiment will be continued for several years to give a long-term picture. It is clear from the present results, however, that effluent water from the intensive African catfish farm can safely be used for irrigation in a sustainable manner after mixing with good quality water and the addition of gypsum, without the danger of sodification or salt accumulation

Környezeti kockázatok térképezése regresszió krigeléssel - Szabolcs-Szatmár-Bereg megye belvíz kockázati térképe

Rövid összefoglaló a belvíz kockázati digitális térképezés kialakításáról Szabolcs-Szatmár-Bereg megye területén