Impacts Of Fertilization On Soil Nutrient And Root Growth Of Larix Olgensis Henry Seedling

Influences of fertiliztion on the growth 1-year old Larix olgensis Henry seedlings were studied. Three experiments were conducted including fertilizer application regime of fertilization compound of controlled release fertilizer (CRF) amount with addition of organic soil amendment (OSA) or not, heterogeneous N supply, and different N to P supply ratio, based on which we detected N and P availability in soil, root growth, nutrient uptake and utilization. The results revealed that:1) Organic C, NH4+-N, NO3--N, and available P content in 0-20cm soil layer was raised by addition of OSA respectively, OSA addition also can promoted the growth of the seedling root, but no significance was found in nutrient uptake and utilization efficiency of root. Nevertheless OSA addition stimulated leaching loss of NO3--N in soil layer of 40-60 cm depth especially with hight amount fertilizer,2) lowN supply created enriched patches of both NH4+-N and NO3--N around taproot, which induced heterogeneous N distribution between patches near and far away from taproot, while high N supply could only created enriched patch of NHl4+-N far from taproot without creating heterogeneous NO3--N distribution, and the main way of nutrient foraging were flush of root length and number of root tips, which increased surface area and volume of root for nutrient uptake.3) root growth was stimulated by N to P supply ratio from 2:1 to 3:1, while it also promoted N uptake according to result of correlation analysis. Based on results of this research, it was suggested for local seedling production managers to adapt CRF of 10gN/m2 approximately added with OSA appropriately as basal application for bare-root seedling culture, when the proper ratio of N to P supply was from 2:1 to 3:1, and homogeneous nutrient application was necessary.