Eight-year (2000-2007) field studies on the effectiveness of controlled drainage in loam sandy soil were carried out in the Lowland of Middle Lithuania. The plot, which has existing subsurface water removal systems operated as conventional drainage was readjusted for the water table management. Two separate systems - 4.9 hectares free drainage (FD) and 5.4 hectares controlled drainage (CD) were arranged. A water level control structure with a riser column and hand operated rigid flap door was installed in the outlet of drainage collector in the manhole at the junction of two collectors. The water table level was allowed to rise to the maximum of 68 cm above the drains. Measurements to record the water table depth, drain outflow quantity and quality were performed. It was determined that in the CD system the annual drainage outflow lasted shorter by 40-62%, at the same time it was reduced by 25% and nitrate leaching - by 20-28% lower in comparison with the drainage operating in an ordinary regime. These indicators varied depending on weather conditions. The water table control in single-acting drainage systems is feasible and has a positive hydrological and environmental impact.

The researches were carried out from 2002-2007 in the upper reaches of the Šušvė River, a Nevėžis tributary, at the pig enterprise Limited company (LTD) 'Litpirma' breeding near the township of Šiaulėnai. LTD 'Litpirma' has been operating since 1978 and produces 25 thousand fattening pigs per year, along with an associated 56 thousand m3 organic fertilizers (liquid manure, slurry and solid manure), which are spread on surrounding agricultural fields. This article presents the impact of a large pig breeding company on the river water quality and quantifies the leaching of nitrogen, phosphorus and potassium (NPK). It is based on the water quality research data collected from an 11.6 km section of the Šušvė River, both upstream and downstream of Šiaulėnai, regarding the drainage water outflow from the fertilized fields and from Šiaulėnai domestic wastewater. Drainage water from 728 ha of fields that have been fertilized with organic fertilizers carry an average of 11.4 tons of nitrogen, 0.073 tons of phosphorus and 5.53 tons of potassium. Changes in NPK quantities carried by this section of the Šušvė were calculated as follows: total nitrogen increased by an average of 83 tons yrE–1 (58%), potassium by 51 tons yrE-1 (54%) and the smallest increase, for total phosphorus, by 1.2 tons yrE-1 (48%). All of these pollutants leached into the river during the cold season (to 60% total phosphorus and to 88% total nitrogen) when there was no vegetative growth. A wet year affects the quantities of leached NPK.

The article analyses the seasonal nitrogen variation in drainage water, when the plants in the field crop rotation are fertilized with slurry during different seasons. The investigations were carried out in 2001-2003 in Juodkiškis experimental site of the Lithuanian Water Management Institute. The investigations established that the largest amounts of nitrogen are leached out in spring and in winter. In the autumn fertilized variant 38.8% more of this element was leached out in winter and spring compared with the variant fertilized in spring. During autumn nitrogen leaching was also 21% higher from the variant fertilized in autumn. It was established that the fertilization rate and dissolved inorganic nitrogen (DIN) supply in soil have influence on the concentrations of this element. During the cold season nitrogen concentrations in drainage water, when plants had been fertilized with slurry in spring, were more affected by the supply of dissolved inorganic nitrogen in soil more compared with the rate of fertilization; and if fertilization had been performed in autumn - the concentrations were more affected by the fertilization rate. In warm season both the fertilization rate and the supply of dissolved inorganic nitrogen in soil had similar influence on the concentrations of nitrogen in the drainage water in both treatments. Meteorological conditions affect nitrogen leaching a lot. During the cold season a greater amount of nitrogen is leached out when the air temperature is higher and during the warm season - when more precipitation falls.

The paper deals with monitoring results of nitrate nitrogen (NO3 --N) run-off in three small agricultural catchments in Latvia (Berze, Mellupite, and Vienziemite) during the period of 1995 - 2007. Continuous flow measurements and water sampling were carried out in two scales - catchment and drainage field. Water quality data was analyzed statistically to identify outliers at various intensity agricultural production systems. The results indicated that with increase of agriculture intensity outlying values are higher and scattered from the rest of the data set thereby the risk of NO3 --N leaching is higher. It can be explained by application of different rates of organic and inorganic fertilization. To analyze water discharge data, cumulative distribution was used. The results show that main part of the water discharge is observed from late autumn to spring, whereas in summer period it is low and stable. The dependence of NO3 --N concentrations on the discharge is expressed by Spearman's correlation coefficient - at catchment scale it is 0.37 in Vienziemite site, 0.39 - in Berze, and 0.44 in Mellupite. Calculated correlation coefficients are statistically reliable.

A current investigation compared various intensive crop rotations (Norfolk, row crops, cereals, short term grass) grown on Cambisols. The study results showed significant effects of N-fertilization of the agroecosystem on mineral N concentration in drainage water and its leaching process. The highest N concentration in drainage water and leaching was determined in the conditions of cereals and row crops rotations. No major impact of the crop rotation on phosphates concentration in drainage water was determined. The average leaching of one by drainage did not exceed 100-140 g haE-1 within a 7 year study period. An experiment was arranged during 1997-2003 years in the Kėdainiai district, Lipliunai willage. A rational and well-considered fertilization ensures high crop productivity and profitable farming as well as steady, which is the main condition for reduced non-point source pollution of water.

Heavy metals are worldwide spread pollutants in soils of functioning as well as abandoned industrial territories, landfills, military areas with its historical contamination, and other sites contaminated by industrial activities. Development of soil and groundwater remediation technologies is a matter of great importance to diminish the hazardous impact of pollution to humans and environment. Sustainable solution can be found for remediation of industrial areas using the stabilization/solidification (S/S) technology, which refers to binding of waste contaminants to a more chemically stable form. Geotechnical properties of soil treated with Portland cement (PC) can be improved when municipal solid waste incineration (MSWI) ash is used as the combined additive. Ash is composed mainly of metals, so environmental impact must be evaluated if it is used as amendment in the cement industry. The use of MSWI ash in stabilization of contaminated soils would be useful for the sustainable environmental management in two ways: S/S contaminated soil gains better geotechnical stability and waste incineration industry gets rid of the ash with high metal content. The aim of research is to provide pilot batch experimental results for leaching of heavy metal compounds when S/S technology is used for contaminated soils using PC and MSWI bottom ash additives. Mineral soils were spiked with copper, PC and MSWI were added in known proportions and leaching tests applied. Main results show that PC addition allows to chemically stabilizing soil; thus, heavy metals are not leached out from combined mass of spiked soil and MSWI bottom ash.

Abstract Studies comparing slurry injection versus spreading have reported inconsistent results so far. The objective of the study was to compare two slurry application methods, injecting and spreading, in terms of influence on sward yields and leaching of nitrogen (N) and potassium (K) from grassland. The experiment was conducted from 2008 to 2011 at the Eerika Experimental Station, Estonian University of Life Sciences. Mini-lysimeters filled with loamy sand soil embedded in three swards (three-species grass mixture (Phleum pratense, Lolium perenne and Poa pratensis), grasses mixture with white clover (Trifolium repens), and grasses mixture with lucerne (Medicago sativa)) were used. Three annual nitrogen rates (60, 120, 180 kg haE-1) in conjunction with the two slurry application methods (injecting and spreading) were applied. Percolated water quantities, N and K content in leachate and the sward yield were measured. N leaching was significantly less with slurry injection while K leaching did not depend on slurry application method. N and K leaching was more affected by sward botanical composition and applied N rate and N:K ratio n slurry than by slurry application method. Sward yields did not depend significantly on slurry application method. Slurry injection is rational only in grasses sward when used N rates are above 120 kg haE-1 yrE-1. Slurry injection may have negative influence on the distribution of white clover in the grasses + white clover sward and thus lead to sward yield decrease.

The investigations were carried out in the Lithuanian Agricultural University Water Research Institute land plots in the Endocalcari Endohypogleyic Cambisols (CMg-n-w-can). The basis of the investigation is 3 variants field experiment. Each variant consists of 3 in 0.54 ha drainage. The traditional arable farming is applied in variant I. In the variant II the land is not being cultivated, but in spring the perennial ryegrass (‘Lolium perenne L’) is being seeded into the spring barley and kept till spring. In the variant III the land is not being cultivated after the harvest and left for the rest till spring. The variant II is distinguished by the minimal mineral nitrogen content. Applied to cultivated and uncultivated land, the min N reserves are increased 51 - 83 and 33 - 40 and 11 - 101 and (38 - 134%) (to 9.5 - 14.3 mg kgE-1 and 152 - 68 and 154 - 61 kg haE-1). The average investigation of N concentration in the drainage water shows, that the minimum concentration of this element was in the second variant. Applied to the traditional farming and uncultivated land, the N concentration is increased by (30 - 42% to 34 and 37 mg lE-1). By average data the min N, leaching by drainage water in the variant II was minimal and about 27 kg haE-1. Applied to the arable farming and uncultivated land, the min N leching is increased (30 - 55%) (to 35 - 42 kg haE-1).

In this article, the results of research on WRI of LUA Juodkiškiai experiment field (1999 – 2003) are discussed. Fertilization and other factors influence over potassium fluctuation, its balance and leaching into drainage water during crop rotation are analysed. In order to evaluate the potassium balance and its quantity passed together with rainfall, seeds, fertilizers and take with the yield (secondary and primary production) was established in plant residues and drainage water. When fertilizing with liquid manure, potassium balance was negative while growing perennial grasses as much potassium was needed to mature their yield. The investigations established that potassium concentration in drainage water and its leaching was increased by precipitation during the research period, and it was reduced by the amount of this element taking out with yield. Soil geochemical environment had influence on the increase of potassium supply in soil. It was established that long-term fertilization with liquid manure had raised the potassium supply in soil. However, from an ecological point of view, potassium leaching did not cause any problems. In all treatments the potassium concentration in drainage water did not exceed permissible concentration.

The investigations were carried out during the period 2006-2011 in the land of the Water resources management institute of ASU, in the village of Lipliūnai on Endocalcari Endohypogleyic Cambisol (CMg-n-w-can). The base of investigations is 3 drainage systems, which contain cereals differing in fertilization and grass crop rotations. The aim of investigations is to determine the crop rotations differing in fertilization and these relations with cycles of phosphorus in agroecosystem. Higher productive was perennial grass crop rotation. In the conditions of cereal crop rotations this productive was 3-46% lesser. The highest concentration of P-PO4 3- in drainage water was received in the conditions of higher fertilization cereals crop rotation while highest concentration of total P was in the conditions of grass crop rotation. The concentration of P-PO4 3- in drainage water essentially depends on amount of mobile P2 O5 in soil, fertilization, productivity of field crops, drainage runoff as well as cumulative balance of P. The highest leaching of P-PO4 3- and total P by drainage was received under the conditions of higher fertilization cereals crop rotation. The leaching of P-PO4 3- essentially depends on fertilization, drainage runoff as well as cumulative and yearly balance of P. The application of all crop rotations was distinguished by positive P balance.