Effects of liming and nitrogen application on the trace element concentrations of pastures in low mountain range
2007
Laser, H.,Justus Liebig Univ., Giessen (Germany). Inst. of Plant Production and Plant Breeding II
Three identical field trials on pastures with different soil pH and organic matter content were established to assess the effect of liming and nitrogen fertilization on the concentration of micronutrients (Se, Cu, Mn, Zn) in herbage. The effect of selenate application on the Se concentration in plants was also tested. Only Mn concentrations and - to a smaller extent - Zn concentrations changed significantly with increasing soil pH. Marked differences between concentrations in primary growths and secondary growths were evident for all trace elements. The effect of added N was negligible. Se concentrations in the plant tissue in plots without selenate application averaged 21.3 microg Se/kg dm in 2002 (SE=18.63) and 48.7 microg Se/kg dm in 2003 (SE=38.97). Sufficient Se concentrations (more than 100 microg Se/kg dm) were only found in herbage fertilized with selenate. Mn concentrations met the requirements for ruminants in most cases (mean Mn concentration in 2002 = 104.2 mg Mn/kg DM; standard error SE=62.76; mean Mn concentration in 2003 = 67.5 mg Mn/kg DM; SE=35.91). The average Zn concentrations were 33.5 mg Zn/kg DM in 2002 (SE=6.46) and 34.0 mg Zn/kg DM in 2003 (SE=7.52). The average Cu concentrations were 10.5 mg Cu/kg DM in 2002 (SE=1.24) and 9.9 mg Cu/kg DM in 2003 (SE=1.93). Therefore, 41.7% of the measured values for Zn and 31.3% of Cu concentrations remained below the recommended levels.
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