Litter fall and nutrient status of green leaves and leaf litter at various compound ratios of fertilizer in sawtooth oak stands, Korea

Abstract

This study was conducted to evaluate the litter fall and nutrient status of green leaves and leaf litter at various compound ratios of fertilizer in 28-year-old sawtooth oak (Ouercus acutissima Carruth.) stands. The compound ratios of the fertilizer were N3P4K1 (100 kg N ha(-1), 133 kg P ha(-1), and 33 kg K ha(-1)), N6P4K1, N2P2K1, N3P8K1, N3P4K2 and N0P0K0 (control). Varying ratios of NPK were applied for three years (2002 - 2004), and the litter fall and green leaves were collected for one year (May 2005 - May 2006) and at the end of growing season (September 2005). Leaf litter was significantly higher (P < 0.05) in the N3P4K2 (3,423 kg ha(-1) year(-1)) than in the N3P8K1 (2,741 kg ha(-1) year(-1)) and N2P2K1 (2,891 kg ha(-1) year(-1)) treatments. The N concentrations of the green leaves were significantly higher in the compound ratios of fertilizer (N3P4K1, N6P4K1, N3P8K1) than in the N0P0K0 treatment, but the N concentrations of the leaf litter were not affected by the fertilizer. The P and K concentrations in the green leaves were significantly higher in the highest dose (N3P8K1 and N3P4K2) of these nutrients than in the N0P0K0 treatment. The nutrient inputs by the leaf litter corresponded to the differences in the leaf litter mass or nutrient concentrations rather than the various compound ratios of fertilizer. Nutrient use and resorption efficiencies were only weakly controlled by various compound ratios of fertilizer. The results indicate that the nutrient status of green leaves may serve as an indicator of various compound ratios of fertilizer, whereas litter fall, nutrient use and resorption efficiency can be attributed to inherent soil conditions or stand characteristics following fertilizer application in sawtooth oak stands.