AGRONOMIJAS VĒSTIS - Latvijas Lauksaimniecības universitāte

AGRONOMIJAS VĒSTIS (Latvian Journal of Agronomy), No.10, LLU, 2008Raudonius, 2003). Correlation and regression coefficients were computed using "Microsta" and"Excel" software.DiscussionThe intensity of plant nutrient leaching depended on soil solution concentration and theamount of percolated precipitation. With the latter increasing (in spring or late in the autumn) thesoil solution was diluted and the concentration of chemical elements declined. Certain variations ofthe concentration occurred not only due to aeration, meteorological conditions but also based onthe composition and amount of fertilizers applied.The data of lysimetric water analyses show that the amount of cations leached varied in thefollowing reducing order: Ca ++ → Mg ++ → K + , anions SO 4- - → NO 3 - → Cl - (Table 1).The concentration of calcium (Ca ++ ) ions in lysimetric water was the highest (90.1 – 160.2mg kg -1 ) of all the cations tested. An especially high concentration of calcium in lysimetric waterwas identified for the soils that had formed from lighter-textured rock – sandy loams, slightly lessfor sandy and loams 129.9, 117.3 and 100.0 mg kg -1 , respectively. The lowest concentration ofcalcium ions (90.1 mg kg -1 ) in lysimetric water was identified for clays. When comparing soilformation sites, the highest concentration of calcium ions in lysimetric water was determined forPlanosols taken from Dubingiai 160.2 mg kg -1 , while the lowest for Luvisols taken from Rumokai90.1 mg kg -1 .The leaching of magnesium (Mg ++ ) is closely related to calcium leaching. Although theconcentration of magnesium ions, compared with calcium concentration in soil solution made upabout 13 %, with the later increasing, the concentration of magnesium ions increased too. Soilpeculiarities had a greater effect on magnesium concentration in the soil solution. The highestconcentration of magnesium ions (24.0 mg kg -1 ) in lysimetric water was identified for Trakai Vok÷Arenosols. Although lime had been applied in Samališk÷s Albeluvisols, the concentration ofmagnesium ions in lysimetric water was very low 10.5 mg kg -1 , like for Juknaičiai Podzols andother sandy soils tested.The concentration of potassium (K + ) ions in lysimetric water was low 2.3 – 5.2 mg kg -1 ,which made up about 3 % of the total sum of cations tested, although this element is attributed tothe mobile classes. Higher contents of potassium are leached into lysimetric water from EastLithuania’s prevailing Arenosols – Trakai Vok÷, Perloja, Dubingiai soils, while the least contentsare leached from the rest of prevailing soils of Lithuania.The concentration of sulphate (SO 4- - ) ions in lysimetric water was the highest of all anionstested. Their concentration in lysimetric water was influenced by the soil sampling site. The lowestsulphate concentration in lysimetric water was determined for Juknaičiai Podzols 61.2 mg l-1andDubingiai Planosols – 70.7 mg kg -1 . The contents of sulphates in lysimetric water of the othertested soils ranged from 118.6 mg l-1to 176.3 mg kg -1 .Nitrates (NO 3 - ). Nitrate nitrogen concentration in lysimetric water was markedly higherthan that of magnesium but lower than that of sulphates. Its content was less affected by the soilthan by the site where it formed. In the lysimetric water of Rumokai Luvisol the concentration ofnitrates was 66.2 mg kg -1 , and that of V÷žaičiai Luvisol 31.9 mg kg -1 . In the lysimetric water of therest of Lithuania’s soils the nitrate content varied from 38.1 to 52.2 mg kg -139