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CONTENTS
ISSN 1392–2335 Water Management Engineering, 34 (54), 2008, 5–15 © Lithuanian University of Agriculture © Water Management Institute of Lithuanian University of Agriculture
THE ENVIRONMENTAL ROLE OF COVER CROP IN MODERN AGRICULTURAL TECHNOLOGIES
Aušra Arlauskienė*, Stanislava Maikštėnienė
Abstract
The paper presents the research data during the period if 2004–2006 carried out in clay loam Cambisol at the Lithuanian Institute of Agriculture Joniškėlis Experimental Station. The experiments were designed to ascertain the effects of different cover crops – red clover (Trifolium pratense L.), white mustard (Sinapis alba L.), mixture of white clover (Trifolium repens L.) and Italian ryegrass (Lolium multiflorum Lamk.) in combination with different straw incorporation methods on mineral nitrogen dynamics in the soil, on nitrate nitrogen leaching and on nitrogen concentration in spring barley yield. During the autumn period cover crops – red clover, mixture of white clover and Italian ryegrass – reduced the amount of mineral nitrogen (Nmin.) in the 0–40 cm layer of the soil more than postcrop – white mustard. Straws used as fertilizers, along with the initial ration of nitrogen (N45), had a tendency to increase the amount of Nmin. in the soil layer of 0–40 cm. All the measures taken (stubble breaking, cover crop and straws) during crop harvesting decreased Nmin. migration into a deeper (40–80 cm) soil layer. Autumn stubble broken, cover crop biomass and straw incorporation increased nitrogen immobilisation and it conditioned a smaller amount of Nmin. in spring in the soil layer of 0–40 cm in comparison with a control treatment. These data compared with the data got in autumn allow to state that the highest amount of Nmin., increased in the treatments with the incorporated biomass of red clover and mixture of white clover and Italian ryegrass. During these treatments in the periods of winter and spring there was observed an essential increase of nitrate nitrogen in the soil filtration water. Cover crop biomass incorporation with straws reduced nitrate nitrogen concentration in the soil filtration water by 19.0 per cent. The first year after straws with the initial (N45) nitrogen fertilizers ration incorporation, increased the spring barely yield and nitrogen concentration in grain. After the incorporation of straw and cover crop biomass the spring barely grain harvest tended to decrease while the red clover biomass increased. The second year after the straw and cover crop biomass incorporation, the spring barely grain harvest and nitrogenity increased essentially. In heavy texture soils in cereal – based rotation (especially where straws were used as fertilizers) nitrogen immobilization and release processes constantly take place, that is why the Nmin. amount in the soil layer of 0–40 cm is small. It reduces the possibilities of nitrogen leaching.
Keywords: clay loam Cambisol, cover crop, mineral nitrogen, straws.
*contact person Dr. Aušra Arlauskienė, Senior Researcher, Lithuanian Institute of Agriculture Joniškėlis Experimental Station. Research interests – researches of soil physical, chemical and biological qualities, plant fertility and nourishment processes and revelation of their regularities; researches of agroecology and regional agricultural systems. Address: LT-39301 Joniškėlis, Pasvalys district, Lithuania. Phone: +370 451 38324. E-mail: joniskelio_lzi@post.omnitel.net. Dr. Stanislava Maikštėnienė, Senior Researcher and Director, Lithuanian Institute of Agriculture Joniškėlis Experimental Station. Research interests – researches of soil physical, chemical and biological qualities, plant fertility and nourishment processes and revelation of their regularities; researches of agroecology and regional agricultural systems. Received 11 2008.
ISSN 1392–2335 Water Management Engineering, 34 (54), 2008, 16–24 © Lithuanian University of Agriculture © Water Management Institute of Lithuanian University of Agriculture
SIMULATION OF NITROGEN LEACHING BY THE SOILNDB MODEL UNDER LITHUANIAN CONDITIONS
Aušra ŠMITIENĖ*, Antanas Sigitas ŠILEIKA, Kazimieras GAIGALIS
Abstract
Process-orientated dynamic models are very useful for assessment of nitrogen leaching under various natural and farming conditions as well as for determination of the most environmentally friendly farming practices. The SOILNDB model explicitly describes water and nitrogen movement and transformation in the soil profile, predicts N leaching via subsurface drainage, and it is the first such model applied under Lithuanian conditions in the study presented here. The SOILNDB model was calibrated and verified by using soil and crop management parameter values measured in the Pikeliai and Lipliūnai (Kėdainiai region) research fields. Model efficiency was calculated by comparing measured and simulated drainage water discharge and NO3-N leaching. The calibrated SOILNDB model simulated drain water discharge and NO3-N leaching (especially annual) fairly well. Model efficiency of monthly and annual drain water discharge was 0.60 and 0.97 for the Pikeliai site, and 0.20 and 0.71 for the Lipliūnai site respectively. Model efficiency of annual NO3-N leaching was 0.53 for the Pikeliai site, and 0.58 for the Lipliūnai site.
Keywords: drain water discharge, nitrogen leaching and SOILNDB model.
*contact person Dr. Aušra Šmitienė, Junior Researcher, Water Management Institute of the Lithuanian University of Agriculture. Research interests – evaluation and modelling of streams water quality. Address: Mituvos 9, LT-50134 Kaunas, Lithuania. E-mail: ausrac@kaunas.init.lt. Dr. Antanas Sigitas Šileika, Director, Water Management Institute of the Lithuanian University of Agriculture. Research interests – monitoring and evaluation of river water quality, modelling of river water quality. Dr. Kazimieras Gaigalis, the Head of Water Resources Sector, Water Management Institute of the Lithuanian University of Agriculture. Research interests – hydrology, monitoring and evaluation of water runoff of small streams. Received 11 2008.
ISSN 1392–2335 Water Management Engineering, 34 (54), 2008, 25–32 © Lithuanian University of Agriculture © Water Management Institute of Lithuanian University of Agriculture
INVESTIGATIONS OF SEDIMENT ACCUMULATION IN OPEN DRAINS
Vaclovas POŠKUS*, Stasys RAGAUSKAS
Abstract
Permanent accumulation of sediment of various intensity is observed in open drains, as distinct from natural watercourses consequently the drains need to be regularly maintained. Investigations were carried out in 72 randomly selected stretches of open drains in the Nevėžis River basin. The article, with reference to data on sediment amount and its mechanical and chemical composition, tries to establish how in causality the process of sediment accumulation is related with both the structural parameters of open drains (slope coefficients, bed width) and parameters determined by the local topography (bed slope, catchment area, soil texture). It is established that the amount of sediment in open drains with low bed slopes and small catchment areas increases with an increase in the sediment accumulation duration; sediment grain-size composition is similar to the one of the soil in which the open drain is dug. In open drains with higher bed slopes and larger catchment areas such dependence does not exist.When average bed slope is higher than 0.7 ‰ and the catchment area is larger than two sq. kilometers, the sediment accumulation intensity depends on the soil texture, bed slope and catchment area. The biogenic material amounts established in the sediment are either close or higher than average amounts of these materials in the adjacent soils, hence there are a lot of soil erosion products from the most fertile topsoil in sediment. The data showed, that the application of self-going bed processes and the minimization of getting of the erosion products through the riparian buffer strips, could be the way to reduce the sediment accumulation in open drains.
Keywords: bed slope, catchment area, open drain, sediment, soil.
*contact person Vaclovas Poškus, Junior Researcher, Water Management Institute of the Lithuanian University of Agriculture. Research interests – natural processes in drainage channels. Address: Parko 6, Vilainiai, LT-58102 Kėdainiai district, Lithuania; e-mail: pvaclovas@delfi.lt. Stasys Ragauskas, Junior Researcher, Water Management Institute of the Lithuanian University of Agriculture. Research interests – ways of ditch maintenance, technological and mechanizational means. Received 11 2008.
ISSN 1392–2335 Water Management Engineering, 34 (54), 2008, 33–38 © Lithuanian University of Agriculture © Water Management Institute of Lithuanian University of Agriculture
STATISTICAL EVALUATION OF WELL-WATER QUALITY
Aurelija RUDZIANSKAITĖ
Abstract
The article presents the research data of the dug well water quality in the karst zone glacial lacustrine clay and moraine sandy loam in the four years (2004–2007). Cluster analysis was used to reveal the formation of common similarities and differences of well water quality formation. In the final stage of the cluster analysis the essential water quality difference between two well groups showed up: one group – wells in the glacial lacustrine clay, the other – wells in the moraine sandy loam. Comparing water quality of all researched wells, there are established statistically significant differences of nitrate concentration (Student’s test tcalc.=2.30-27.6>t95 % =1.66), the amounts of the organic substances (tcalc.=1.82-11.34<t95 %=1.66) and mainly insignificant differences of ammonium nitrogen concentration (tcalc.=0.06-1.40 < t95 %=1.66). The nitrate concentration in all wells in the moraine sandy loam, during the time of investigation, was higher than in the glacial lacustrine clay and it exceeded the highest allowed value from 1–33 times.The highest ammonium nitrate concentration and the quantity of organic substances were found in the wells of glacial lacustrine clay and shallow wells (moraine sandy loam).
Keywords: ammonium nitrate, cluster analysis, nitrate, organic substance, well water.
Dr. Aurelija Rudzianskaitė, Senior Researcher, Water Management Institute of the Lithuanian University of Agriculture. Research interests – environmental engineering, relations between the regime and pollution of surface and subsurface water. Address: Parko 6, Vilainiai LT-58102, Kėdainiai district, Lithuania. E-mail: aurelija@water.omnitel.net. Received 12 2008.
ISSN 1392–2335 Water Management Engineering, 34 (54), 2008, 39–47 © Lithuanian University of Agriculture © Water Management Institute of Lithuanian University of Agriculture
SOIL USE PRACTICE IMPACT ON MINERAL PHOSPHORUS LEACHING
Saulius GUŽYS*, Zita PETROKIENĖ
Abstract
The investigations were carried out in the LAU VM institute land plots in the Endocalcari Endohypogkeyic Cambisol (CMg-n-w-can). The basis of the investigation is nine drainage systems and 3 variants. Every variant made 3 drainage lines (0.54 ha). A traditional arable system was applied in variant I. Soil tillage was not applied in variant II. In this variant in spring barley or spring wheat was sown and left until spring. In the variant III the soil was not tilled and left until spring. The least phosphoric soil (in water extract) was distinct in variant II both in mg kg-1 that and kg ha-1 dimension. Applying the arable agriculture as well as no soil tillage the concentration of P-PO43- in water extract increased 8–40 and 13–12 % far up 0.268– 0.216 mg l-1. Under the conditions of arable agriculture and soil no tillage amount of the accumulated P-PO43- (0–40 cm) comparing with variant II increased by 20 and 33 % to 0.72–0.80 kg ha-1. Variant II was distinct by smaller soil mobile phosphorus (P2O5) which made up 118 mg ka-1, or 17–24 % smaller than in variant I (arable agriculture) and variant III (no soil tillage). The essential soil bulk density varies in only 0–20 cm soil layer. The smallest soil bulk density was gained in the conditions of variant II. The least one was gaines under the conditions of traditional arable system. Under the condition of variant I the most abundant yield of spring barley, and spring wheat was gained. The biggest removal of phosphorus with crops was gained under the conditions of variant II where undercrop was grown. There was the biggest drainage runoff. The average data of P-PO43- concentration in drainage water show that the smallest concentration of this element was in variant II (growing ryegrass) (0.01 mg l-1). Applying traditional agriculture as well as no soil tillage the concentration of P-PO43- increased 3–4 times (to 0.03 and 0.04 mg l-1). The leaching by drainage water of P-PO43- was smallest in variant II (with ryegrass) and made 0.009 kg ha-1. Applying arable agriculture and no soil tillage leaching of P-PO43- increased 67–100 % (to 0,015– 0,018 kg ha-1).
Keywords: agriculture, concentration leaching, phosphorus, soil.
*contact person Dr. Saulius Gužys, Senior Researcher, Water Management Institute of the Lithuanian University of Agriculture. Research interests – agrochemistry, agroecology, agricultural hydrology. Address: Parko 6, LT-58102, Vilainiai, Kėdainiai district, Lithuania. Phone: +370 671 06124. E-mail: s.guzys@water.omnitel.net. Zita Petrokienė, Junior Researcher, Water Management Institute of the Lithuanian University of Agriculture. Research interests – investigations on plant nutrient migration and balance, water protection. Received 12 2008.
ISSN 1392–2335 Water Management Engineering, 34 (54), 2008, 48–56 © Lithuanian University of Agriculture © Water Management Institute of Lithuanian University of Agriculture
ON THE RELATIONSHIP BETWEEN THE URBANIZATION AND THE HYDROLOGICAL RESPONSE OF A CATCHMENT
Tamara BENABDESSELAM*, Yahia HAMMAR
Abstract. The features of the hydrological response of a catchment to a rainy event depend on the morphology of the catchment and also on the importance of the event. The urbanization, translated by impermeabilisation of which the consequences are the growth of the streamed volumes and the decrease of the superficial flow times, increases the risk of flooding by runoff. In this work, we have studied the effect of the urbanization on the hydrological response of a catchment located in the south part of the city of Annaba (Algeria). To simulate the transformation rainfall-flow, the non-distributed model of linear reservoir has been chosen. The obtained results show that in case of the urbanization, the lag time of the considered catchment is a lot shorter and also the peak flow increases considerably.
Keywords: design storm, hydrological response, IDF curves, linear reservoirs model.
*contact person Tamara Benabdesselam, Senior Lecturer, University of Annaba, Algeria. Research interests – hydrology, runoff and storm water management, aquatic environment protection. Address: Department of Hydraulic, University of Annaba. BP 12 Annaba 23000 Algeria. E-mail: kondratievat@yahoo.fr. Dr. Yahia Hammr, Associate Professor, University of Annaba, Algeria. Research interests: urban hydraulic, waste water sewage treatment and management, environment protection. Received 12 2008.
ISSN 1392–2335 Water Management Engineering, 34 (54), 2008, 57–62 © Lithuanian University of Agriculture © Water Management Institute of Lithuanian University of Agriculture
influence of irrigation on EVAPOTRANSPIRATION AND Productivity OF STRAWBERRY under Lithuanian climatic conditions
Laima TAPARAUSKIENĖ
Abstract. Investigations into evapotranspiration by the strawberry cultivar “Senga Sengana” under natural and optimal soil moisture conditions was carried out during the periods 1996–1999 and 2001–2004, in order to determine the influence of irrigation on water consumption by the cultivar. Experiments were done to prove the necessity of strawberry irrigation under Lithuanian climatic conditions. Comprehensive investigations into strawberry plant evapotranspiration and the influence of irrigation on strawberry yield, single berry size, runner production and the assimilation area of leaves were conducted in Central Lithuania. Evapotranspiration was determined during the period of plant growth (May-September), by the weighing type of lysimeters, with soil (loamy soils) monolith surface area of 1.0 m2 and depth of 1.1 m. It has been established that in order to avoid stressful conditions and to ensure optimal conditions of soil moisture, strawberry plants should be irrigated in dry years as well as in years having average humidity. Under natural conditions during May-August, plants used 313 mm of water, while under optimal soil moisture conditions they consumed from 299 to 557 mm of water, or 366 mm on average. Strawberry plants evaporate an average of 3 mm/day of water. Maximal evapotranspiration was 5.5–6 mm/day (in 2002). During the flowering period, the average water consumption was 2.6 mm/day and during fruiting it was 3.2 mm/day. Irrigation has a significant influence on the increase of total yield, weight of berries, runner production and leaf area. The differences between irrigated and non-irrigated plants are obvious and statistically significant (p – 0.05).
Keywords: evapotranspiration, fruit size, irrigation influence, soil moisture, yield.
Dr. Laima Taparauskienė, Associate professor, Lithuanian University of Agriculture. Research interest – crop water requirements. Address: Universiteto 10, Kaunas-Akademija, LT-53067. Phone: +370 37 75 23 80. E-mail: ltlaima@yahoo.com. Received 12 2008.
ISSN 1392–2335 Water Management Engineering, 34 (54), 2008, 63–74 © Lithuanian University of Agriculture © Water Management Institute of Lithuanian University of Agriculture
CONTROLLED DRAINAGE INFLUENCE ON SOIL MOISTURE
Edmundas RAMOŠKA*, Vytautas MORKŪNAS, Alvyda Šaulienė
Abstract
The article analyses how to use water rationally in the drained area and to make a more favourable humidity regime in the soil during a vegetation period affected by drainage in the mineral soil. The researches were carried out in two fields, where the surface inclination in the nearby bed part is up to 1 %, of a calcareous gleyic loam brownsoil (RDg4-k2) in the central part of a mid plain of Lithuania in 2000–2008. There was observed a periodicity of an affluent in the drainage net and its abatement/subsidence during spring and summer period, soil humidity dynamics between drain and nearby drain in the layer of 0–60 cm. The researches were carried out in a warmer and drier season than usual. The average annual weather temperature was 1.6 °C higher than norm: one year was wet, three years were dry and five years were average damp. The possibilities of supplying the soil water resources while damming the drainage during the period of vegetation depended on the plants and meteorological conditions. After the sowing period in spring, while damming the drainage, the height of the affluent did not reach a rated designed height and it was higher while damming in the period of winter wheat vegetation. In May the affluent duration period in the drainage net was 19–31 days in 8 cases out of 9, in June-August – 1 case out of 6 it lasted 6–31 days. The dam obstructed up to 5.0 mm, in summer – 14 mm of the runoff. According to the average data, the resources of soil humidity in the layer of 0–30 cm of a control and dammed field in spring and summer reached 66.3–52.1 and 67.2–52.9 mm and statistically did not differ significantly. In the subsoil layer of a dammed field, the humidity resources reached 2–4 mm in April–May and it was statistically higher than in the control field. In April and May the soil humidity of a dammed field lasted 8.8 % longer, whereas optimal one was shorter than in the control field. The humidity resources in the soil layers of the dammed field, when the soil was getting drier, were declining slower. In both fields the link of the humidity resources with the average monthly weather temperature and precipitation was weak or average and statistically insignificant (Ff <F05). The impact of morphological factors to the soil humidity resources was stronger in the dammed field than in the control field (R2 = 30–35 ir 28–30). A direct connection between hydrothermic coefficient (HTC) and humidity duration in the soil layers of the investigated fields in May–August was not identified. Humidity resources in the nearby drain sector depended on the height of the affluent. There was a stronger connection in the deeper layers and it manifested more in the trench but not near it. When the affluent abated from H max to Hmin drain humidity resources in the nearby drain sector reduced 10 mm in average. During the investigation period the productivity winter wheat and barley grain in the dammed and ordinary drainage at between drain did not differ significantly. In spring and summer of insufficient humidity the affluent positively affected the productivity of winter wheat.
Keywords: affluent, crop, drainage regulation, humidity resource.
*contact person Dr. Edmundas Ramoška, Senior Researcher, Water Management Institute of the Lithuanian University of Agriculture. Research interests – environmental engineering and landscape management, regulation of water regime in mineral soils. Address: Parko 6, Vilainiai, LT-5048 Kėdainiai district, Lithuania. Phone: +370 347 6 80 08. E-mail: e.ramoska@takas.lt. Dr. Vytautas Morkūnas, Senior Researcher, Water Management Institute of the Lithuanian University of Agriculture. Research interests – environmental engineering and landscape management, land draining. Alvyda Šaulienė, Junior Researcher, Water Management Institute of the Lithuanian University of Agriculture. Research interests – environmental engineering relations between the regime and pollution of surface and subsurface water. Received 12 2008.
ISSN 1392–2335 Water Management Engineering, 34 (54), 2008, 75–81 © Lithuanian University of Agriculture © Water Management Institute of Lithuanian University of Agriculture
Maintainance of spawning migration conditions for fish in the Vytinis branch of the Nemunas
Gražina Žibienė*, Alvydas Žibas
Abstract
Kuršių lagoon is the most important water body for fishery in Lithuania. Most fishes of Kuršių lagoon migrate for spawning to shallows of the lagoon, some of these fishes (roaches, breams, zanders, burbots and others) reach for the Nemunas branches and for the Minija river. Rare and protected fish species as salmon, sea-trout swim over the Kuršių lagoon, enter the Nemunas branches and migrate upriver for spawning to the Minija, the Jūra and other rivers’ upper reaches. From year to year spawning migration conditions go worse due to shoal of the Nemunas branches, especially at their entries in the lagoon. The main cause of this negative process is an accumulation of sediments transported by the Nemunas water at the sectors of slower flow. The article dwells on the spawning conditions detoriation causes in the Vytinis branch (one of the Nemunas branches), on the problems related to it, on the possible solutions and possibilities to ensure the required spawning migration conditions. It is estimated that periodically dredging, repairing of piers and jetties are necessary for the maintenance of spawning migration conditions and decreasing the getting shallow mouths of the Nemunas branches. The dredging and repairing of piers and jetties were stopped in 1990 due to the lack of financing and are not restarted (do to environmental reasons too) yet.
Keywords: dredging, sediments, spawning migration.
*contact person Gražina Žibienė, Associate professor, Lithuanian University of Agriculture. Research interests – environment protection yield, hydrotechnical structures, evaluation of environmental impact. Address: Universiteto 10, Kaunas-Akademija, LT-53067. Phone: +370 37 752 393. E-mail: Grazina.Zibiene@lzuu.lt. Alvydas Žibas, Lecturer, Lithuanian University of Agriculture. Research interests – hydrotechnical structures, evaluation of environmental impact. Received 12 2008.
ISSN 1392–2335 Water Management Engineering, 34 (54), 2008, 82–90 © Lithuanian University of Agriculture © Water Management Institute of Lithuanian University of Agriculture
THE IMPACT OF POND ON THE NITROGEN CONCENTRATION IN THE WATER OF THE KRAUJUPIS RIVER
Saulius KUTRA*, Laima BERANKIENĖ
Abstract
The paper analyses the impact of a small pond (0.6 ha) on the water quality. The investigations were carried out in 2004–2007. It was established that nitrogen compound concentration in the stream fluctuates due to a reduced water speed and chemical reactions when water flows through a small pond. In cases of casual pollution water quality changes greatly when very much polluted water is diluted in the pond and nitrogen compounds slowly assimilate into the organic compounds. Nitrogen compounds participate in the synthesis of an organic substance. During its decomposition in the pond nitrogen compounds segregate again – it is a secondary pollution. Ammonium nitrogen concentration does not change unambiguously. During a warm period of a year the concentration of this element most often declines while during a cold period it significantly inclines. The largest amount of ammonium nitrogen in the stream when it reaches 30 mg l-1 is the secondary pollution. Annual average ammonium nitrogen concentration in the inflowing water is 0.93 mg l-1, in effluent water it is 0.40 mg l-1. The impact of a pond ecosystem on a nitrate concentration in water is more equivalent than that of ammonium. Nitrate nitrogen concentration when water flows through the pond decreases all year through but there are cases when it increases. The average nitrate nitrogen reduction is 1.3 mg l-1. The average nitrate nitrogen reduction when water flows through the pond reaches 41 %. The greatest alteration of nitrate concentration is when a residence time of stream water in the pond is comparatively short from 5–100 hours. When the residence time becomes longer, concentration alteration is lower. In a long period of time the balance of compound transformation comes to equilibrium and nitrate concentration in the water because of its stay in the pond does not change.
Keywords: compounds, Kraujupis, nitrate pollution, pond, stream.
*contact person Dr. Saulius Kutra, the Head of Water Protection Department, Water Management Institute of the Lithuanian University of Agriculture. Research interests – environmental engineering and landscape management, GIS, pollution modelling, application of remote sensing. Address: Parko 6, Vilainiai, LT-58102 Kėdainiai district, Lithuania. Phone: +370 347 6 82 47. E-mail: kutra@water.omnitel.net. Dr. Laima Berankienė, Senior Researcher, Water Management Institute of the Lithuanian University of Agriculture. Research interests – environmental engineering and landscape management, hydrology, river pollution. Received 12 2008.
ISSN 1392–2335 Water Management Engineering, 34 (54), 2008, 91–99 © Lithuanian University of Agriculture © Water Management Institute of Lithuanian University of Agriculture
SIMULATION OF NITROGEN LEACHING COEFFICIENTS FOR CROP GROUPS
Aušra ŠMITIENĖ*, Antanas Sigitas ŠILEIKA, Kazimieras GAIGALIS, Giedrius BAIGYS
Abstract
Agricultural impact on the environment can be minimised by applying agro-technical measures for reduction of nitrogen pollution for each crop, and this can be performed in the most reasonable way if nitrogen leaching from each crop is known. The aim of this work was to model various crop rotations and to calculate nitrogen leaching coefficients for the main crop groups with the help of the nitrogen leaching model SOILNDB and the actual crop management data. Under the conditions of Central Lithuania during 1996–2005 the following nitrate nitrogen leaching coefficients were determined: 18.7 kg ha-1 for spring cereals, 14.1 – for winter cereals, 21.1 – for row crops, and 4.5 kg ha-1 for perennial grasses. The simulated nitrogen leaching coefficients for each crop group was a little bit higher than the mean nitrogen losses in the analysed catchment (measured at the river water measuring post), and it was similar to the nitrogen leaching from arable land and pastures measured by other Lithuanian researchers.
Keywords: crops, nitrogen leaching, SOILNDB model.
*contact person Dr. Aušra Šmitienė, Junior Researcher, Water Management Institute of the Lithuanian University of Agriculture. Research interests – evaluation and modelling of streams water quality. Address: Mituvos 9, LT-50134 Kaunas, Lithuania. E-mail: ausrac@kaunas.init.lt. Dr. Antanas Sigitas Šileika, Director, Water Management Institute of the Lithuanian University of Agriculture. Research interests – monitoring and evaluation of river water quality, modelling of river water quality. Dr. Kazimieras Gaigalis, the Head of Water Resources Sector, Water Management Institute of the Lithuanian University of Agriculture. Research interests – hydrology, monitoring and evaluation of water runoff of small streams. Giedrius Baigys, Junior Researcher, Water Management Institute of the Lithuanian University of Agriculture. Research interests – water protection, variation and improvement measures of soil water regime and hydrophysical characteristics. Received 12 2008.
ISSN 1392–2335 Water Management Engineering, 34 (54), 2008, 100–105 © Lithuanian University of Agriculture © Water Management Institute of Lithuanian University of Agriculture
RESEARCH ON THE CONVERSION OF SLURRY INTO FERTILIZERS
Sigita Marija STRUSEVIČIENĖ, Zenonas STRUSEVIČIUS*
Abstract
The traditional way of dealing with manure – storage, transportation, spreading in the fields – is currently applied very successfully, but is economically very expensive. People complain about very unpleasant smells, which are caused by gasses (indole, merkaptanas, hydrogen sulphide, ammonia) being released from the manure. Scientists are searching for other ways of handling manure which try to convert it to less harmful substances, reduce its odour and at the same time make it thicker by extracting its water content. The aim of our work was to evaluate the composition of slurry after processing it mechanically, and to test the effectiveness of the application of new coagulants and flocculants on its clarification. Two types of slurry were used: (1) fresh, from the Pagryžuvis (Kelmė district) pig complex and (2) processed in biogas reactors, from the Lekėčiai (Šakiai district) pig complex. Anionic coagulants such as aluminium chloride AlCl2, ferrous sulfate Fe2(SO4)3 and pollycrilamide cationic flocculent Magnofloc 1011 were applied to clarify manure. The process of mechanical separation of slurry at a pig farm produces a thick fraction and sewage. 38–49 % of dry substances and 10–14 % of nitrogen are removed into a thick fraction. 40–44 % of organic pollutants can be removed from the aerated sewage under constant processing by coagulants and flocculants. The best result in pollutant removal from sewage is achieved when it is processed with 1.5 kg m-3 norm of aluminium saline (AlCl) and 3.0 g m-3 norm of flocculant Magnoflocion. After processing with chemical substances, sewage is formed that is similar to animal slaughter wastewater. There are 7630–9650 mg O2 l-1 of organic pollutants (by BOD7), 3210–3950 mg l-1 of nitrogen compounds and 31.3–99.0 mg l-1 of phosphorus compounds. Chloride concentration in the wastewater exceeds the largest allowed quantity by 2.8–5.3 times.
Keywords: coagulants, flocculants, pollutants, slurry, wastewater.
*contact person Dr. Sigita Marija Strusevičienė, Senior Researcher, Water Management Institute of the Lithuanian University of Agriculture. Research interests: ecology and landscape management, the impact of the handling of manure, urine and wastewater on the environment. Dr. Zenonas Strusevičius, the Head of Water Treatment Laboratory, Water Management Institute of the Lithuanian University of Agriculture. Research interests: natural wastewater treatment methods. Address: Parko 6, Vilainiai, LT-58102 Kėdainiai district, Lithuania. Phone: +370 347 68020. E-mail: zenonas@water.omnitel.net. Received 12 2008.
ISSN 1392–2335 Water Management Engineering, 34 (54), 2008, 106–117 © Lithuanian University of Agriculture © Water Management Institute of Lithuanian University of Agriculture
Impact of intensive livestock farming on surface water quality in Latvia
Laima Berzina*,Ritvars Sudars,Viesturs Jansons
Abstract. The article describes the influence of the livestock farming on surface water quality to upgrade understanding about the level and environmental impacts of nutrient pollution from agriculture. There is also a need to monitor agricultural pollution in respect of the EU legislation and international agreements. Nutrient concentrations and chlorophyll-a data in runoff for three monitoring sites in monthly water samples are analyzed. Application of a Median test indicates that there are significant differences in variation of nitrogen and biochemical oxygen demand and not so evident dispersion of phosphorus and chlorophyll-compounds, comparing water quality parameters in all observed sites. The paper also reveals the basic tendencies in seasonal dynamics of these compounds and relationships of the water quality parameters and represents statistical summary tables and box plot data. All parameters and the basic tendencies are analysed with reference to the conditions relevant to Latvia nitrate vulnerable zones.
Keywords: agriculture point source pollution, chlorophyll-a, nutrients, surface water.
*contact person
Laima Berzina,
Lecturer, Lauksaimniecbas University of
Agriculture, Latvia. Address: Akademijas street 19, Jelgava LV-3001, Latvia. Phone: +370 3022037. E-mail: Laima.Berzina@llu.lv. Dr. Ritvars Sudars, Professor, Lauksaimniecbas University of Agriculture, Latvia. Research interests: ecology and environmental protection. Dr. Viesturs Jansons, Professor, Lauksaimniecbas University of Agriculture, Latvia. Research interests: ecology and environmental protection. Received 12 2008.
ISSN 1392–2335 Water Management Engineering, 34 (54), 2008, 118–123 © Lithuanian University of Agriculture © Water Management Institute of Lithuanian University of Agriculture
PURIFICATION POSSIBILITIES OF UNPROCESSED WASTEWATER IN THE TREATMENT FACILITIES AT A MILK COLLECTING STATION
Simanas AŠKINIS
Abstract
The paper presents research data on the treatment of unprocessed wastewater in the experimental treatment facilities at a milk collecting station. The research showed that two-stage constructed wetlands at milk collecting stations can act, without any additional processing, as a wastewater treatment within permitted limits for a period of time: the organic pollutants according to BOD5 in the treated wastewater make on average 10.2 mgO2/l, Ntotal – up to 14.8 mg/l, Ptotal – up to 2.6 mg/l. However, constructed wetlands can only actually function for short periods under such a regime, due to the large amount of suspended sediment covering the upper sandy layer and the wastewater gathering at their surface. Reeds, which normally help to improve sand filtration, disappear under anaerobic conditions causing the functionality of the constructed wetlands to decline. In wastewater treatment facilities where wastewater is processed (primary treatment), the amount of organic pollutants getting into the stream reduces by 99.5 %, Ntotal by 78.8 % and Ptotal by 97.2 %. Where wastewater is not processed, the equivalent figures are 98.8 %, 53.2 % and 58.0 % respectively; the amount of easily dissolvable organic pollutants in open water reservoirs increases by 2.2 times and Ntotal increases by 2.5 times. To maintain wastewater treatment at the milk collecting stations within permitted imits, without using any primary treatment, the amount of easily dissolvable organic pollutants should not be higher than 1400 mgO2/l, Ntotal – 47 mg/l, and Ptotal – 8 mg/l.
Keywords: pollutants, treatment effectiveness, wastewater treatment.
Dr. Simanas Aškinis, Senior Researcher, Water Management Institute of the Lithuanian University of Agriculture. Research interests – ecology and environmental engineering, the impact of the management and usage of slurry and wastewater on the environment, researches on the transformational processes of pollutants. Address: Parko 6, Vilainiai 5048, Kėdainiai district, Lithuania. Phone: +370 347 6 80 20. E-mail: s.askinis@takas.lt. Received 12 2008.
ISSN 1392–2335 Water Management Engineering, 34 (54), 2008, 124–131 © Lithuanian University of Agriculture © Water Management Institute of Lithuanian University of Agriculture
THE ŠUŠVĖ RIVER POLLUTION BY BIOGENIC SUBSTANCES
Saulius KUTRA*, Laima BERANKIENĖ
Abstract
The article presents biogenic substance leakage research carried out at 7 sites along the Šušvė River during the period 2006–2008. It was established that the concentration of nitrogen (as ammonium, nitrates and total nitrogen) declines from the upper reaches to the lower reaches of the river, whereas there is some increase in phosphorus concentration. These changes are not significant and the river, from its headwaters to its outfall, remains in cleanliness class IV. Only a very dry season may provoke a change to class III, due to a high concentration of nitrogen (3 times higher than the high allowed concentration). While calculating the amount of substance leaching, the study established that if the catchment area enlarges, the load of nitrogen and phosphorus gradually enlarges too. Comparing the upper reaches of the river (upstream from Šiaulėnai) with the lower reaches (at Josvainiai), the quantity of nitrogen shows the least increase (from 36 to 119 kg day-1, or by 3.3 times) while total phosphorus shows the largest increase (from 8 to 48 kg day-1, or by 6 times). Fluctuations in the concentration and leaching of the biogenic substances (ammonium, nitrates, total nitrogen and phosphorus) in the river as a whole reveal that the 2 largest ponds (Vaitiekūnai and Angiriai) have the greatest effect. Due to their impact, the quantity of total nitrogen decreases by ca. 37 % and total phosphorus increases by ca. 25 %. This results in the territory of the ponds and the river between them having lowest ratio of nitrogen to phosphorus (N:P) that is nearest to optimal ratio for biological processes. As part of the total pollution leaching into the river, the percentages of concentrated pollutants are approximately 2 % ammoniac nitrogen, 0.1 % nitrate nitrogen, 0.5 % total nitrogen and 4 % total phosphorus, and these may affect the river at distances from as little as 100m to a few kilometres from the actual source of pollution.
Keywords: nitrogen, phosphorus, substance leaching, water quality.
*contact person Dr. Saulius Kutra, the Head of the Water Protection Department, Water Management Institute of the Lithuanian University of Agriculture. Research interests – environmental engineering and landscape management, GIS, pollution modelling, application of remote sensing. Address: Parko 6, Vilainiai, LT-58102 Kėdainiai district, Lithuania. Phone: +370 347 6 82 47; e-mail: kutra@water.omnitel.net. Dr. Laima Berankienė, Senior Researcher, Water Management Institute of the Lithuanian University of Agriculture. Research interests – environmental engineering and landscape management, hydrology, river pollution. Received 12 2008. |
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