Contents 

ISSN 1648-4363

Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University

of Agriculture, 2003, 23(45)

The paper presents the results of the investigation on phosphorus removal from wastewater in wastewater treatment facilities arranged on A. Visockas dairy farm in Birzai district. The research was carried out in the period of 2000-2002.

A. Visockas is the owner of a large up-to-date dairy farm (100 milking cows) containing modern milking and milk refrigerating equipment. Wastewater produced on the farm is saturated with large amounts of organic matter and nutrients and contains about 30 mg/l of total phosphorus load, which is about 3 times higher than in domestic wastewater. The largest proportion of phosphorus fractions (68.0%) is that of mineral phosphorus; solid organic and soluble organic phosphorus make up 24.7% and 7.3% respectively. When treating wastewater in a three-chamber septic tank and constructed wetlands with sand bed, more than 97% of organic matter and about 58% of phosphorus load are removed, from which 28.3% of phosphorus remain in a septic tank and 19.7% are retained in a constructed wetland. During the process of wastewater treatment in a septic tank (under anaerobic conditions) the largest proportion of retained phosphorus is that of solid organic one (54%). The retention of mineral and soluble organic phosphorus is insignificant.

After the biological treatment in a constructed wetland with sand bed (under aerobic conditions) the average phosphorus concentration in wastewater is

12.6 kg/l, from which 84.1% is mineral phosphorus.

Keywords: wastewater, pollutants, phosphorus fractions, treatment efficiency.

• Dr. Zenonas Strusevicius  (contact person), Head of Water Treatment Laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – handling of wastewater and manure, investigation of pollutants transformation processes.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone: +370 347 6 80 20. E-mail: zenonas@water.omnitel.net.

• Dr. Sigita Marija Struseviciene, senior researcher, Water Treatment Laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – handling of manure, urine and wastewater.

Received 05 2003.

ISSN 1648-4363

Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University

of Agriculture, 2003, 23(45)

The paper deals with the evaluation of pollution of the period of 1960-2000 in a mid-size basin of the river Susve with developed agricultural activity. A number of changes in landscape structure (structure of agricultural land use, structure of croplands, drained land areas, arrangement of ponds) that do not contribute to the chemical load directly, but affect different chemical processes in the soil and thus accelerate the migration of nutrients, are discussed in the paper.

Calculated values of different pollution sources (precipitation, fertilization, inhabitants, animals) show that the largest NPK input into the basin is via fertilization (62% of total pollution load). Other chemical pollution sources include animals (26%), precipitation (11%) and human activity (1%). Fertilizers are a major pollutant of the basin with phosphorus (82%) and nitrogen (58%).

The most intensive agricultural activity was observed in the period of 1975-1990, when animal density was 0.9 animal unit (AU) for 1 ha of agricultural land use (at the moment animal density is only 0.4 AU). The mineral fertilizers use increased from 60 to 220 kg for 1ha of arable land. Annual N, P2O5 and K2O input together with manure and mineral fertilizers was on the average 140, 56 and 119 kg/ha of agricultural land use respectively. These are not significant indices, however the mentioned factors may adversely affect the river water quality under the conditions of improper farming, low coefficient of fertilizers uptake, animal concentration in large complexes, improper handling of manure and ignorance of environment protection requirements.

Keywords: land use, agricultural activity, crop structure, animals, mineral fertilizers.

• Dr. Ramute Aksomaitiene  (contact person), 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, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone: +370 347 6 80 00.

• Dr. Laima Berankiene, senior researcher, Modeling and Informatics Laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – environmental engineering and landscape management, hydrology, pollution of rivers.

Received 05 2003.

ISSN 1648-4363

Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University

of Agriculture, 2003, 23(45)

The paper discusses changes in water quality and leached nutrient amounts in the mid-size river Susve (tributary of the Nevezis).

In 1960-1965, mineral nitrogen and phosphate phosphorus concentrations contained in the Susve river water were 0.5 mg/l and 0.015 mg/l respectively; this is considered as background concentration. In 1992-1993, average nitrogen concentration increased 10 times, phosphorus concentration increased 2.7 times (5.2 and 0.04 mg/l respectively). Nutrient concentration shows decreasing tendency during the last years.

Leached NP amounts depending on their concentration and river runoff were comparatively small within the study period (1992-2001): on the average there were leached 9.3 kg/ha of total nitrogen, 0.11 kg/ha of total phosphorus, 6.9 and 0.06 kg/ha of mineral nitrogen and phosphorus respectively. Leached NP amounts (10.2 and 0.7% respectively) is insignificant contribution into total pollution which occurs in the basin as a result of the whole agricultural activity.

Considering the river water pollution classification applied in Lithuania, since 1995 the river Susve has been described as follows: according to pollution with phosphorus the river is clean, according to pollution with mineral nitrogen it is semi-polluted; total nitrogen concentration exceeds the maximum permissible concentration 1.8-3.4 times (2.5 mg/l), although according to the EU Nitrate Directive (MPC – 5.6 mg N/l) the river would still be considered as a clean one.

In the paper the relationship between the largest pollution sources (mineral fertilizers, animal number) and river water quality were evaluated. No strong effect of pollution on the increase or decrease in nitrogen amount in river water was determined (except for emergency cases). For more significant changes in river water quality, an 8-10-year period should pass from the moment of increased pollution in the river basin. This may be explained by the nitrogen metabolism in agroecosystem and water as well as by soil buffering characteristics, self-purification and pollution-resistance of geosystem.

Keywords: water quality, nutrient leaching, nitrate, nitrogen, phosphorus, pollution.

• Dr. Ramute Aksomaitiene  (contact person), 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, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone: +370 347 6 80 00.

• Dr. Laima Berankiene, senior researcher, Modeling and Informatics Laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – environmental engineering and landscape management, hydrology, pollution of rivers.

Received 05 2003.

ISSN 1648-4363

Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University

of Agriculture, 2003, 23(45)

The paper presents total evaporation results in the river Susve basin in 1940-2001. Several different methods were applied for the estimation of evaporation (water balance method, Ivanov method, Konstantinov method), and the results were compared considering 10-year moving average values.

As the obtained data shows, 75% (475 mm) of total precipitation amount experienced by the Susve basin evaporate here. During the years with favorable conditions for the evaporation (wet and warm vegetation period), evaporated precipitation amount is 567-578 mm, i.e. total annual precipitation amount plus 113-147 mm of ground water store. The least significant evaporation (396-399 mm, or 60-64% of total annual precipitation amount) is observed during cold or dry periods. Annual error of evaporation calculations is about ±20 mm; annual evaporation variation is 0.10. According to 10-year moving average values, evaporation curve is inversely proportional to cyclic precipitation fluctuations. As water balance-related calculations show, water store in the Susve basin may reach ±160 mm. No major influence of increasing temperature on the evaporation has been observed so far. The range of fluctuating water store decreased from ±160 to ±5 mm within the period of 1940-2001.

The Ivanov method was most suitable for the calculations of the evaporation from the river Susve basin in 1940-1980. Later a more intensive evaporation was observed due to increasing air temperature and soil moisture deficit. When applying the Konstantinov method, a 15% higher evaporation values were obtained. However, this method did not show long-term fluctuations related to the abundance of water of a particular year.

Keywords: evaporation, air temperature, relative air moisture, partial water-vapor tension, water store in the basin, moving average values.

• Dr. Saulius Kutra  (contact person), Head of Modeling and Informatics Laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – environmental engineering and landscape management, GIS, pollution modeling, application of remote sensing method.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone: +370 347 6 82 47. E-mail: kutra@water.omnitel.net 

• Dr. Laima Berankiene, senior researcher, Head of Modeling and Informatics Laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – environmental engineering and landscape management, hydrology, pollution of rivers.

Received 05 2003.

ISSN 1648-4363

Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University

of Agriculture, 2003, 23(45)

The paper discusses the chemical composition of ground water in drained moraine sandy loam and peat soils of the active karst zone. The dependence of chemical compounds concentrations on the acidity-alkalinity index pH as well as on the changes of water level is also analyzed.

Ground water mineralisation process in peat soil is 1.1-1.2 times faster than in loam soil. Water under investigation was of neutral or slightly alkaline reaction. With increasing pH values the amounts of sulphate and ammonium ions were increasing, while that of nitrates had a decreasing tendency in ground water.

As the study results show, lower levels of ground water predetermine larger total sum of ions it contains. A strong correlation connection was observed between the fluctuations of water levels and the elements (Ca2+, Mg2+, SO42- and HCO3-) affecting chemical composition of ground water.

Keywords: ground water, water level, pH index, concentrations of chemical compounds.

• Dr. Aurelija Rudzianskaite, senior researcher, Hydromelioration Laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – environmental engineering and landscape management, researches of drainage and ground water regime and pollution.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone: +370 347 6 80 08. E-mail: aurelija@water.omnitel.net 

Received 05 2003.

ISSN 1648-4363

Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University

of Agriculture, 2003, 23(45)

Due to the imperfection of up-to-date theory of suspension flow new experimental investigations on its further development are still being performed. The investigation on measuring instruments used for the study of turbulent flow and fluctuations of sediment concentrations is of great importance.

It is not an easy matter to interpret the readings of acoustic instrument, as they measure the visible area of sediment particles, not the sediment concentration itself. Therefore, the readings depend not only on sediment concentration but also on the diameter of sediment particles and on the additional self-irradiation of particles by sound waves reflected from the particles, especially when the sediment concentration is high (>10-20 g/l). Consequently, the connection between the sediment concentration and instrument readings is complex. However, it is often simplified assuming linear dependence that is correct only in the case of homogeneous sediments the concentration of which is comparatively low. However, the experimental sediments cannot be fairly homogeneous, thus the estimation of sediment non-homogeneity contributes to the accuracy of study results. Simplified approaches cause the bias errors and are not acceptable when the investigation is to be carried out with great accuracy. Thorough study of various sources of bias errors that occur when investigating the sediment-laden flow is presented by M.Muste (2002). The author emphasizes the necessity to find out methods to avoid them.

This paper analyzes the dependence of acoustic instrument readings on the factors mentioned, the estimation of non-homogeneity of investigated sediments and the necessity of accurate analysis.

Keywords: suspension flow, acoustic instrument, turbulence, concentration distribution.

• Dr. habil. Alfonsas Rimkus, freelance researcher, Exploitation Laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – hydraulics of hydrostructures, river bed processes.

• Dr. Romualdas Pukstas  (contact person), senior researcher, Polder Laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – ground physics, measurement devices.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone: +370 347 6 80 09.

Received 05 2003.

ISSN 1648-4363

Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University

of Agriculture, 2003, 23(45)

Fine suspended sediments (clay and silt particles) existing in floodwater contain much biogenic matter, therefore when investigating the pollution process in the Curonian Lagoon and the Baltic Sea, evaluation of the amount of these particles was of great importance. It was necessary to determine grain-size composition of suspended sediments. A special method based on the measurement of sediment deposition process was created. The measurements were taken with the help of an infrared radiation-related instrument. Readings of the instrument were written in the memory of a computer, which helped to study the dynamics of change in sediment concentration. The paper discusses methods of flow investigation and study of measurement data.

Keywords: suspended sediment, concentration, sediment composition, grain-size analysis.

• Dr. habil. Alfonsas Rimkus, freelance researcher, Drainage Maintenance Laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – hydraulics of hydrostructures, river bed processes.

• Dr. Romualdas Pukstas  (contact person), senior researcher, Polder Laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – ground physics, measurement devices.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone: +370 347 6 80 09.

Received 05 2003.

ISSN 1648-4363

Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University

of Agriculture, 2003, 23(45)

The semi-closed water body – the Curonian Lagoon is being polluted rather heavily with products leached from agricultural fields and carried by the river Nemunas. Therefore the sedimentation of those materials in inundated meadows of the delta is of great importance. A quasi-2-D hydrodynamic model of suspension flow was created for the investigation of this process.

Roadbeds traced across the delta valley produce adverse results. Moreover, a new way is being projected, therefore investigation on the estimation of optimal road trace and location of new bridges was performed. The mathematical model was supplemented as the construction of the new roadbed resulted in more complex hydraulic conditions. The paper discusses this supplementing process and analyzes the model itself.

Keywords: suspended sediment, hydraulic investigation.

• Dr. habil. Alfonsas Rimkus, freelance researcher, Exploitation Laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests: hydraulics of hydrostructures, riverbed processes.

• Dr. habil. Saulius Vaikasas  (contact person), senior researcher, Exploitation Laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests: environmental engineering and landscape management, hydraulic modeling, riverbed processes.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone: +370 347 6 81 09. E-mail: s.vaikasas@delfi.lt . 

Received 05 2003.

ISSN 1648-4363

Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University

of Agriculture, 2003, 23(45)

Water quality, including river water, subsurface drainage water and water in wells, was compared in two small agricultural watersheds: Graisupis (Lithuanian Middle Plain) and Vardas (hilly area of Eastern Lithuania).

The average water runoff in the river Graisupis (0.035-0.072 l s-1 ha-1) was often smaller than the runoff in the river Vardas (0.048-0.128 l s-1 ha-1), except for autumn and early winter period.

The highest allowed concentration of total nitrogen (Ntotal) and phosphorus (Ptotal) in the water body – receiver (2.5 mg N l-1 and 100 µg P l-1) was exceeded in 66% and 43% of monthly water samples of the river Graisupis and in 51% and 15% of samples of the river Vardas during 1996-2002. Almost every year the annual mean flow-weighted Ntotal concentration in the river Graisupis (4.61-12.7 mg l-1) exceeded the concentration in the river Vardas (3.40-10.9 mg l-1). The annual mean flow-weighted Ptotal concentration in the river Graisupis was 56-293 µg l-1, in the river Vardas it was 33-245 µg l-1.

Annual Ntotal losses were from 8.9 to 21.7 kg ha-1 in the Graisupis watershed and from 6.1 to 23.2 kg ha-1 in the Vardas watershed. Annual Ptotal losses in the Graisupis watershed differed almost 8 times: from 83 to 655 g ha-1; Ptotal losses in the Vardas watershed were from 96 to 521 g ha-1. Due to different geographic conditions between the watersheds, higher water runoff has determined comparatively high nutrient losses in the Vardas watershed.

The average Ntotal concentration of all investigated drainage systems in the Graisupis watershed was 10 mg l-1, in the Vardas watershed it was 4.6 mg l-1. Ptotal concentrations were 250 and 65 µg l-1 respectively. Larger amounts of nutrients in the drainage water of the first watershed determined worse water quality in its river.

Water quality in 9 monitored wells in both watersheds was very different, as it was greatly influenced by the management of the environment around the wells. The water of one of the wells in the Graisupis watershed experienced a decrease in average NO3-N concentration which dropped from 13 to 1.6 mg l-1 in a 5-year period after the establishment of a protective buffer zone around the well.

Keywords: nitrogen, phosphorus, river, drainage, well.

• Dr. Kazimieras Gaigalis, Head of Water Resources Laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – hydrology, water flow and water quality monitoring.

  • Address: Mituvos 9, Kaunas LT-3009, Lithuania. Phone/fax + 370 37 33 12 70. E-mail gaigalis@water.omnitel.net .

• Jurate Marculaniene, junior researcher, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – chemical analysis of water, water quality evaluation.

• Ausra Smitiene, junior researcher, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – water quality investigations in small agricultural watersheds.

Received 05 2003.

ISSN 1648-4363

Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University

of Agriculture, 2003, 23(45)

The efficiency of the land use depends on the compatibility of suitable natural and economical conditions of the locality. The purpose of the work is to analyse the present situation, to determine and estimate the opportunities for the expansion of land tenures of farms at the same time allowing the effective functioning of domestic industry and rational land use.

For the carrying out the analysis in 2000-2002, the following agricultural territories of different natural zones have been chosen: Western zone – Plunge district, Middle Lithuania zone – Kaunas district and Eastern zone – Utena district. 291 farmer (who has declared the crops) from seven subdistricts has been questioned.

The calculation of normative expenses is necessary not only for the territory arrangement of one farm, but for the changing of the land plot dislocation of agricultural enterprises or farmers by expanding or rearranging farms differently or planning the dislocation of farming buildings, etc. For the estimation of technological characteristics of plots more exact data should be used.

Keywords: land, farm, management, plot, field, massif.

Received 05 2003.

ISSN 1648-4363

Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University

of Agriculture, 2003, 23(45)

In Voke Branch of the Lithuanian Institute of Agriculture the investigation on the effects of calcareous, organic and siliceous sediments and their mixture with manure in the crop rotation on sandy loam cambisols were carried out in 1994-1999.

Results of the investigation demonstrated that calcareous sediment and limestone decreased the acidity of soil. Organic and silicon sediments had no effect on those indices. Only larger rates of organic (40 t/ha) and siliceous (100 t/ha) sediments increased the content of total nitrogen and humus in soil. Fertilization with mineral fertilizer compensated the amount of mobile phosphorus and potassium, which is needed for plants to grow.

The application of sediments had positive influence on the quality of physical characteristics of sandy loam cambisols. The organic and siliceous sediments increased the humidity and porosity, and decreased the density of soil more than calcareous sediment. Calcareous sediment improved the mentioned physical indices of soil more than limestone.

Keywords: sediments, manure, soil, characteristics, yield.

• Eugenija bakSIENE, Deputy Director of Voke Branch of Lithuanian Institute of Agriculture.

  • Research interests – agronomy-agrochemistry.

  • Address: Zalioji aikste 2, LT-4002 Vilnius, Lithuania. Phone: +370 5 2 64 54 30. E-mail: eugenija.baksiene@voke.lzi.lt .

Received 05 2003.

ISSN 1648-4363

Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University

of Agriculture, 2003, 23(45)

Well-functioning land market is the background determining further development of farms and expansion of agricultural land plots. Its balanced land prices would contribute to the establishment of stable home market. The existing prices of agricultural land reflect neither the value of drainage systems nor their condition. For intensive farming on drained land areas, constant investments into the maintenance of land reclamation systems are needed. Expenses on the maintenance works that need to be done in order to ensure good draining condition of drainage systems make an inevitable effect on the extent of profit gained from the usage of agricultural land.

The paper analyses the results of drained land appraisal with respect to the condition of land reclamation systems in the process of the formation of land market. After the investigations on the condition of drainage systems had been done and the systems had been distributed according to risk factors of possible failures, the average probability of drainage failures in Kretinga district was determined to be 60%. The value of drained land is suggested to be corrected applying land price correction coefficient that determines the reliability of drainage functioning in certain vicinities.

Keywords: land market, normative land price, maintenance of land reclamation systems, reliability, correction coefficient.

• Dr. Valentinas Saulys  (contact person), senior researcher, Head of Exploitation Laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – environmental engineering and landscape management, researches of water filtration process through drainage backfill, investigation of the usage and maintenance of land reclamation equipment.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone: +370 347 6 81 09. E-mail: valentinas@water.omnitel.net .

• Dr. Nijole Bastiene, senior researcher, Exploitation laboratory, Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – environmental engineering and landscape management, researches of drainage system reliability and exploitation efficiency.

ISSN 1648-4363

Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University

of Agriculture, 2003, 23(45)

The paper presents results of the investigations on changes in fill grain-size composition of the lower part of the dam downstream as well as on the intensity of water seepage characteristics. The objective of the investigations was to evaluate statistically the process of seepage fill deformations. It was determined that dam fill is statistically homogeneous, and a comparatively small-scale sampling – at least 6 fill samples taken from a place susceptible to seepage deformations and from a stable place (control place) of the dam slope – would be sufficient to prove the effects of mechanical suffusion. If no signs of suffusion are determined by study results, further comparative investigation is needed in order to discover a danger to the dam to be disintegrated.

Keywords: earthfill dam, seepage deformations, changes in fill grain-size composition.

• Dr. Povilas Sukys, Head of Hydromelioration Laboratory, Water Management Institute of Lithuanian University of Agriculture, associate professor at Economics Department, Kaunas Technological University.

  • Research interests – environmental engineering and landscape management, interrelations between soil moisture, ground water regime and pollution.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone +370 347 6 80 08. E-mail: lygis@water.omnitel.net .

Received 05 2003.