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CONTENTS Narimantas ŽDANKUS. Linearization of orifice group characteristics Stefanija MISEVIČIENĖ. Slurry application impact on nutrient leaching in light-texture soils Edmundas RAMOŠKA. Investigations on the efficiency of subsoil slit-tillage
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 1(4), 2004 DISSOLVED INORGANIC NITROGEN AND PHOSPHATE CYCLES IN DIFFERENT CROP ROTATIONS Ramutė AKSOMAITIENĖ*, Saulius GUŽYS, Zita PETROKIENĖ A current investigation has compared various intensive crop rotations (Norfolk, row crops, cereals, perennial grass) cultivated in autonomous land plots in Cambisols. Investigations were carried out in the period of 1997–2003 in the study object of Water Management Institute of LAU. A row crop rotation was distinguished by highest productivity (980 GJ ha-1 total energy over period of investigations). The study results have shown significant effects of N-fertilization and N balance in the agroecosystem on N accumulation in soil, N concentration in drainage water and its leaching process. The highest DIN (dissolved inorganic nitrogen) content in soil (0–100 cm deep) was found in crop rotation with row crops and perennial grass. The highest average DIN concentration in drainage water and total leaching was determined in cereals and row crop rotations. No major impact of the applied crop rotations on phosphates concentration in drainage water and their leaching was determined. A rational and well-considered fertilization ensures high crop productivity and profitable farming as well as steady, close to neutral N balance, which is the main factor for reduced non-point source pollution of water. Keywords: crop rotations, nitrogen, phosphorus, drainage water, leaching, balance.
*contact person Dr. Ramutė Aksomaitienė, senior researcher, head of Chemical Analysis Laboratory, Water Management Institute of Lithuanian University of Agriculture. Research interests – investigations on plant nutrient migration and balance in basins of streams and drainage systems, water protection. Address: Parko 6, LT-58102, Vilainiai, Kėdainiai district, Lithuania. Phone: +370 347 6 80 00. E-mail: chal@water.omnitel.net. Dr. Saulius Gužys, senior researcher, Chemical Analysis Laboratory, Water Management Institute of Lithuanian University of Agriculture. Research interests – agrochemistry, agroecology, agricultural hydrology. Zita Petrokienė, junior researcher, Chemical Analysis Laboratory, Water Management Institute of Lithuanian University of Agriculture. Research interests – investigations on plant nutrient migration and balance, water protection. Received 11 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 1(4), 2004 ACCUMULATION OF MORAINE-SOIL DEFLATION PRODUCTS IN DRAINAGE CHANNELS IN WINTER Romanas LAMSODIS*, Vaclovas POŠKUS Soil deflation processes occur not only during the warm period of the year but also in winter when fields after tillage and sowing are dry or frozen and not covered or occasionally covered with snow. When accumulating into drainage channels, the deflation products might accelerate the growth of bottom sediment, which would result in shallow channels. As the results of direct measurements show, in moraine soils of Middle Lithuanian Lowland the mean amount of aeolian sediment accumulated into mid-sized channels situated in arable land or nearby it is 5.5×103 kg km-1 per winter. Compared to deflation-affected field soil, the grain-size composition of sediment may be very different. This depends on the deflation conditions in a certain field in certain winter. The greatest amount of wind-blown soil particles accumulate in a leeward slope of a channel: here the confidence value of mean depth of a sediment layer is between 0–2.22 mm, while in the channel bottom section and on a windward slope this value reaches only 0–0.26 mm. In spring, when certain amount of snow is washed from flooded slopes total amount of winter-time aeolian sediment input into the bottom section of channel bed may grow up to 2–6 mm (maximum value of confidence interval). It was also observed that the riparian protective belts of the channels performed the positive role in retention of wind-set-in-motion soil particles. Keywords: deflation, winter, drainage channel, moraine plain.
*contact person Dr. Romanas Lamsodis, senior researcher, Water Management Institute of Lithuanian University of Agriculture. Research interests – drainage systems and environment, function ability of drainage systems, biodiversity of agrolandscape. Address: Parko 6, Vilainiai, LT-58102 Kėdainiai district, Lithuania. E-mail: lammor@delfi.lt. Vaclovas Poškus, junior researcher, Water Management Institute of 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. Received 11 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 1(4), 2004 INVESTIGATION ON THE CHANGES IN MANAGEMENT OF THE NEMUNAS FLOODPLAIN AND THEIR EFFECT ON THE LANDSCAPE FORMATION Diana LATSANOVSKY, Juozapas VYČIUS* The Nemunas river delta is recognized as one of the most important wetland ecosystems in Lithuania and in the Baltic region. A great variety of habitats characterizes this complex wetland. It includes large raised bogs, fens, shallow lakes mostly surrounded with a wide reed belt, large complexes of fish ponds and huge areas of wet seasonally flooded meadows. Some islands of the delta are covered with flooded forests, permanently or seasonally flooded forests also cover some other parts of the territory. For centuries people have been living in the Nemunas floodplain adapting to the conditions set by annual floods; farming and utilization of natural resources have been forming the basis of its local economy. Significant development in industrial and agricultural activities in the 20th century together with dramatic changes in the state system over the last 100 years have affected not only the economy, but also the entire environment of the Nemunas floodplain. Thus, the example of the development of these areas provides a unique opportunity to explore the effects of changes in the state social system on the state’s imposed relationship between humans and nature and as a result on the landscape. First changes of natural landscape of this territory began in the 17th century with construction of small dikes to protect farmers houses and small plots of land from the destructive effects of flood water. By the year 1944 it was the developing industry of the Nemunas floodplain region which gave a start to major landscape changes; impact of the developing agriculture in this period was less significant. The Second World War brought radical changes to the social system of Lithuania and the Nemunas floodplain, too. The land was nationalized and agriculture was based on collective farming. By the late 1990s, the Nemunas floodplain had a highly developed agriculture, intensive peat mining, large summer and winter polders systems, vast fishery ponds. These changes most definitely caused increasing flooding problems, loss of biodiversity and landscape values, increased sedimentation and pollution problems. Even the creation of five nature reserves did not compensate destructive effects of agricultural activity on the landscape of the region. After Lithuania regained its independence in 1990, the new government acknowledged the importance of the area for the conservation of biodiversity and implemented the rational policy for protection of natural ecosystems and landscape. Some fragile balance between nature and humans was achieved but certain new problems appeared. The paper aims to explore the landscape implications of wetland management contradictions in the Nemunas floodplain during this complex period of its evolution. Keywords: floodplain, the Nemunas delta, landscape, formation, polders.
*contact person Diana Latsanovsky, student for doctor degree, Royal Holloway University of London, England. Research interests: environment risk assessment, cultural geography. Dr. Juozapas Vyčius, associate professor, Hydraulic Engineering Department, Lithuanian University of Agriculture. Research interests: nature protection, hydropower, wastewater treatment. Address: Universiteto 10, LT-53361 Kaunas-Akademija, Lithuania. Phone: +370 37 75 23 93. E-mail: ht@nora.lzua.lt. Received 11 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 1(4), 2004 SLURRY APPLICATION IMPACT ON NUTRIENT LEACHING IN LIGHT-TEXTURED SOILS Stefanija MISEVIČIENĖ The paper presents study results on nutrient leaching in crop rotation fields where slurry was applied. The studies were carried out within the period of 1999–2003. The study results show close relationship between nutrient leaching and fertilization. When applying the highest amounts of nitrogen, phosphorus and potassium (on the average 199, 36 and 174 kg ha-1 respectively), leached amounts of the elements are also highest (on the average 22.6 kg ha-1of nitrogen, 0.03 kg ha-1 of phosphorus and 0.8 kg ha-1 of potassium). Under the conditions of lower rates of applied nutrients (on the average 70 kg ha-1 N, 14 kg ha-1 P and 76 kg ha-1 K), leached amounts of the elements are 3.4, 1.5 and 2 times less respectively. Nutrient leaching also much depends on precipitation amount. In 2000, the study object experienced 613.2 mm of precipitation therefore nutrient leaching was most intensive in this period (the average leached NPK amounts were 26.6, 0.04 and 1.7 kg ha-1 respectively). The study period of 2001 was less abundant in precipitation (478 mm), which determined less intensive NPK leaching (on the average 4.3 kg ha-1 N, 0.02 kg ha-1 P and 0.6 kg ha-1 K). Nitrogen leaching mostly depended on the cultivated crops. In 2001, when red clover of the 2nd year of use was grown, Ntotal concentration was lowest – 3.7 mg l-1 and its leaching was 4.3 kg ha-1. The highest average Ntotal concentration (21.4 mg l-1) was determined when sugar beet was grown in the test field (here Ntotal leaching was 22.6 kg ha-1). Fluctuations in nitrogen concentrations contained in drainage water depended much on DIN (dissolved inorganic nitrogen) content in soil (by 60% in spring (r=0.77) and 80% in autumn (r=0.64)). No relation between P, K concentrations in water and mobile P, K content has been determined. The study results also show that nutrient leaching is 11.5, 42.8 and 20% less intensive when slurry is applied in spring than in autumn. Keywords: slurry, nutrient leaching.
Dr. Stefanija Misevičienė, researcher, Water Treatment Laboratory, Water Management Institute of Lithuanian University of Agriculture. Research interests – ecology and environmental studies, effects of manure handling on the environment, investigation on pollutants transformation processes. Address: Parko 6, Vilainiai, LT-58102 Kėdainiai district, Lithuania. Phone: +370 347 6 80 21. E-mail: s.miseviciene@takas.lt. Received 11 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 1(4), 2004 AMMONIA LOSSES FROM ORGANIC FERTILISERS APPLIED TO CROPLANDS IN VIEW OF EXPERIMENTAL STUDIES IN POLAND Stefan PIETRZAK The paper presents measurements of ammonia emissions from organic fertilisers applied to croplands. Measurements were carried out in the years 2002–2004 in four dairy farms in Podlasie Province (Poland). Micrometeorological method of passive dosimetry (based on mass balance of volatile ammonia released from definite sources) was used. Eight series of measurements, 3–4 days long each were performed. In four cases ammonia losses were measured from manure applied to arable lands, in three cases from liquid manure and in one case from slurry applied to grasslands. In relation to the initial amount of total nitrogen the sum of ammonia losses were found to range between 2.3 and 7.4% from manure, 22.2–41.7% from liquid manure and 24.2% from slurry. High ammonia losses from liquid organic fertilisers were associated with a high concentration of ammonium-nitrogen (N-NH4) that varied from 75 to 82% of total nitrogen (Ntotal). The amount of ammonia emitted from manure depended on the time and method of its storage. Keywords: organic fertilisers, croplands, ammonia emissions, reduction of ammonia losses.
Dr. eng. Stefan Pietrzak, Institute for Land Reclamation and Grassland Farming in Falenty. Research interest – nutrient management. Address: 05–090 Raszyn, Poland. Phone: +48 22 7200531. E-mail: S.Pietrzak@imuz.edu.pl. Received 11 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 1(4), 2004 INVESTIGATIONS ON THE EFFICIENCY OF SUBSOIL SLIT-TILLAGE Edmundas RAMOŠKA Heavy textured soils are usually distinct for inefficient drainage functioning due to insufficient water permeability of deeper soil layers. This work evaluates the effectiveness of different subsoil improvement means. The hydraulic regime and economical expedience were analyzed in two types of soils where several subsoil improvement ways using straw were applied. The report gives the data of the period 1999–2003 about the effects of agro-melioration means (soil slit-tillage with straw incorporation, plough-in of straw by a segment plough) on the hydraulic regime and productivity of plants in drained heavy soils. The studies were carried out in two objects situated in the northern part of Middle Lithuanian Plain (Pasvalys district). As the study results show, the application of soil slit-tillage with straw incorporation in Hapli-Epihypogleyic Luvisols with a low hydraulic conductivity index during wet and semi-wet years had a positive impact on draining efficiency within the study period. The hydro-modules and the runoff coefficient of intensive drainage functioning were higher and the annual runoff lasted longer. The most intensive drainage functioning of comparable variants was observed in cold periods – about 60–90% of total yearly runoff occurred in winter and spring. The agro-melioration means applied in Endocalcary–Endohypogleyic Cambisols with the average coefficient of hydraulic conductivity showed no stronger effects on soil water tables during wet periods. A stronger impact on soil water regime was that of the landscape. Less significant effect of the landscape on water tables was determined in the fields where deep plough and slit-tillage with straw incorporation were applied. The additional crop yield obtained within a 4-year period compensated the energy output of applied agro-melioration means and ensured the energy output economy. Keywords: amelioration of subsoil, drainage outlet, water table levels, energy output.
Dr. Edmundas Ramoška, senior researcher, Hydromelioration Laboratory, Water Management Institute of Lithuanian University of Agriculture. Research interests – environmental engineering and landscape management, regulation of water regime in mineral soils. Address: Parko 6, Vilainiai, LT-58102 Kėdainiai district, Lithuania. Phone: +370 347 6 80 08. E-mail: e.ramoska@takas.lt. Received 11 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 1(4), 2004 EVALUATION OF ORGANIC POLLUTION AND NUTRIENT LOAD IN STREAMS OF THE KARST ZONE Aurelija RudzianskaitĖ The paper presents the study results of organic pollution and nutrient load in two streams (basin areas 1.63 and 2.02 km2) flowing via different textured soils in karst zone. As the study results have shown, according to the average annual BOD7 values water in the streams was considered as clean; according to DIN (dissolved inorganic nitrogen) concentration the stream water was considered as slightly or moderately polluted. Higher amounts of DIN and organic matter were determined under the conditions of higher humus content in the soil (more humus (0.8–3.0%) was observed in glacial lacustrine soils), uneven runoff distribution (when its formation process is interrupted) and decreasing water temperatures. More intensive precipitation determined higher Ptotal concentrations by 32–39%. Keywords: streams of karst zone, BOD7 index, nitrogen, total phosphorus.
Dr. Aurelija Rudzianskaitė, senior researcher, Water Management Institute of Lithuanian University of Agriculture. Research interests – environmental engineering, researches of drainage and ground water regime and pollution. Address: Parko 6, Vilainiai, LT-58102 Kėdainiai district, Lithuania. Phone: +370 347 6 80 08. E-mail: aurelija@water.omnitel.net. Received 11 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 1(4), 2004 MODELLING OF NITROGEN RETENTION PROCESSES IN THE NEMUNAS FLOODPLAIN Saulius VAIKASAS,* Alfonsas RIMKUS Flooding of the river Nemunas floodplain preserves natural retention capacity of pollutants in water of the main canal and improves farming conditions on the inundated meadows of the valley. By the means of mathematical modelling it was established that nitrogen concentration decreased by 10–40% causing self-purification process on the flooded meadows of the Nemunas floodplain. Nitrogen retention is mostly observed in the zones of stagnant water and depends on the velocities of flood current. Heavy metals and nutrients are absorbed by tiny clay and mud particles deposited in the meadows. Therefore, retention of the Nemunas flood water and sediments is useful for both soil fertilization and water quality improvement in the Curonian Lagoon. Currently, the actual effect of floodwater purification is about 10–15%. Intensification of water self-purification process can be achieved by creating a vegetation cover in inundated meadows. Keywords: floodplain, water quality, sedimentation and water purification.
*contact person Dr. habil. Saulius Vaikasas, senior researcher, Exploitation Laboratory, Water Management Institute of Lithuanian University of Agriculture. Research interests – environmental engineering and landscape management, hydraulic modeling, river bed processes. Address: Parko 6, Vilainiai, LT-58102 Kėdainiai district, Lithuania. Phone: +370 347 6 81 09. E-mail: s.vaikasas@delfi.lt. Dr. habil. Alfonsas Rimkus, freelance researcher, Exploitation Laboratory, Water Management Institute of Lithuanian University of Agriculture. Research interests – hydraulics of hydrostructures, river bed processes. Received 11 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 1(4), 2004 LINEARIZATION OF ORIFICE GROUP CHARACTERISTICS Narimantas ŽDANKUS The paper analyzes phenomenon of the liquid flow through a single round orifice under small pressure head. It is proved that the orifice flow rate coefficient C relates to relative head H/D better than that to Reynolds number Re. The experimental C – H/D relationship is suggested for design of orifice group. The quantity of orifices of the group is accepted according to required linearity of the meter characteristics. The levels of orifices are computed from their number applying our technology. To avoid the interaction between the orifices, our recommended distances should be observed. If the high accuracy of flow measurements is required, orifice elevations are verified by the computer-aided technology. Keywords: orifice, orifice group, discharge, linearity, characteristics.
Prof. habil. dr. Narimantas Ždankus, head of Geo-engineering Department, Kaunas University of Technology. Research interests – fluid mechanics. Address: Studentų 48, LT-51367 Kaunas, Lithuania. Phone/Fax: +370 37 45 36 08. E-mail: narzda@mf.ktu.lt. Received 10 2004. |
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