Effects of fertilization on uptake and availability of N and P nutrient pool of Larix olgensis seedlings.

In order to explore luxury nutrient uptake of the seedlings prior to field planting under conventional fertilizing regimes, Larix olgensis seedlings(one-year old) were selected as materials. Biomass, concentrations and contents of N and P of two-year old seedlings were tested under different fertilization treatments. The nutrient use efficiency and vector nomogram of N and P were also analyzed. The results show that the amount of fertilizer significantly affected the biomass(Ppool=0.028 5; Pintact=0.032 5), P concentration(Ppool=0.002 2; Pintact=0.041 8) and P content(Ppool=0.004 3; Pintact=0.030 1). Biomass and nitrogen transferring to nutrient pool occurred with low values of nutrient use efficiency. Vector analysis indicated that N deficiency and P in dilution status were observed in both nutrient pool and intact seedlings. In order to induce luxury nutrient uptake of seedlings, fertilization regimes should be optimized by conducting both exponential N nutrient loading during growth period and fertilization of P in late-season. Simultaneously, nutrient pool strength could be selected as an indicator for seedling performance after planting.