AGRONOMIJAS VĒSTIS - Latvijas Lauksaimniecības universitāte

AGRONOMIJAS VĒSTIS (Latvian Journal of Agronomy), No.10, LLU, 2008Se mg/kg0,400,350,300,250,200,150,100,05550 600 650 700 750 800 850 900Precipitation mmY= -0,3357+0,0014x-0,0000009453x 2R=0,38Se mg/kg0,400,350,300,250,200,150,100,055,4 5,6 5,8 6,0 6,2 6,4 6,6 6,8 7,0 7,2Average annual temperature o CY= -0,0523+0,0355x,R=0,28Figure 1. Selenium concentrations in the soil based on precipitation and average annualtemperatureSoil samples for the determination of selenium concentration were taken from the combisolCMg-n-w-cap fields of the long-term (30 years) fertilisation experiment in Sk÷miai. The Kriūkaiexperiment (eight years in duration) is located on silty loam brown soil. The lowest seleniumconcentration was in the soil samples taken unfertilized plot. Selenium concentration increase wascaused predominantly by nitrogen fertilisation (ammonium nitrate) (Figure 2).Se mg/kg0,20Sk÷miaiSe mg/kg0,27Kriūkai0,190,260,180,250,170,240,160,230,150,220,140-0-0 0-180-180 120-180-1800,210-0-0 0-90-90 120-180-180Figure 2. Long-lasting fertilisation effect on selenium amount in soils of Sk÷miai and Kriūkaifields, ±sxSoils were grouped according to phosphorus content, texture and acidity in order todetermine a relation between the soils richness in phosphorus and selenium concentration. Norelation between the soil richness in phosphorus and selenium concentration was found.Soil samples were also grouped according to available from plants potassium content. Thefollowing relation was determined: acid (pH up to 5,0) light texture soils, containing largeramounts of potassium available from plants, contain higher concentrations of selenium as well(Table 2).22