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AbstractQuality of produced seedlings relies mainly on the substrate on which it grows and develops. In this study, three common biomaterials – pine bark, carbonized rice husk and mushroom sawdust, were mixed with growing media in two ratios (10% and 20%) to assess their effects on growth and seedling quality of Prunus sargentiiseedlings in containerized production system. Generally, 10% pine bark treatment showed the highest results among others in some parameters of seedling growth – height and root collar diameter. For total biomass, 10% rice husk treatment was highest, followed by 10% pine bark treatment. Seedling quality index at 10% rice husk treatment resulted highest (24% increase compared to control) followed by 10% pine bark treatment (20% increase compared to control). Our results suggested that both rice husk and pine bark can be used in 10% mixed ratio to growing media to gain the qualified P. sargentiiseedlings in forest nurseries, which in turn, will help to establish successful reforestation in the field.

AbstractBiochars are used to improve soil quality and crop productivity as well as to increase carbon sequestration in soil. However, it is important to identify the characteristics of biochar prior to its application because of the positive and negative effects on soil and crop productivity. The purpose of this study was to investigate the effects of charcoals on the growth and seedling quality of Quercus serrataand Prunus sargentiiin a containerized seedling production system. Two of the charcoals used in our research were from oak tree; one produced at 1200 °C and the other at 700 ∼ 800 °C, and a bamboo charcoal produced at about 800 °C. Three charcoals were mixed with artificial soil (peat moss, perlite, and vermiculite with a ratio of 1:1:1 (v/v/v)), and applied commercial fertilizer at two concentrations; 0.5 and 1.0 g L−1. Growth parameters, such as height, root collar diameter, and dry weight, were decreased in charcoal treatments compared to control. However, charcoal treatments significantly increased the quality index of seedlings by 8.3% in Q. serrataand by 19.9% in P. sargentii. Our results suggested that charcoal can be applied to improve seedling quality in the containerized Q. serrataand P. sargentiiseedling production system.

ABSTRACTBiochar can be used as a kind of soil amendment in crop production, but there are few studies on containerized seedling production in forestry. The purpose of this study was to investigate the amount of torrefied wood to mix with growing medium for Zelkova serrataand Fraxinus rhynchophyllaseedling production in a containerized system. We used torrefied wood made from chips of Quercus accutissima, which was mixed with growing medium by 0%, 10%, 20%, 30%, and 40% in volume. We applied two levels of 0.5 g/L (1×) and 1.0 g/L (2×) commercial fertilizer for fertilization treatment. Generally, growth parameters such as height, root collar diameter, and dry weight were comparable among 0%, 10%, and 20% mixed ratios, but those at 30% and 40% mixed ratio were lower than other mixed ratios. The 2× fertilization significantly increased height by 29%, root collar diameter by 18%, total dry weight by 52%, and quality index by 31.4% compared to the 1× fertilization across mixed ratios. Our results suggest that torrefied wood can be substitutable for 20% of the growth medium in total volume in containerized Zelkova serrataand Fraxinus rhynchophyllaseedling production systems.

ABSTRACTLand use change greatly affects the carbon cycling of the Earth. Soil carbon and nutrient stock distributions were identified in the five land use types: Quercusspp. mixed forest (QM); Larix leptolepisplantation (LP); Castanea crenataplantation (CP); Malus pumilaorchard (MF); and abandoned fields (AF). Carbon and nutrient concentrations in the organic horizon and the soil were significantly different according to land use type and soil depth. Carbon concentrations of the organic horizon were higher in QM than in AF, while phosphorus concentrations were higher in MF and AF by 7 times and 4 times compared to that in QM and LP, respectively. The total carbon was distributed in A horizon by 51.8% and in B horizon by 38.0%. The amount of phosphorus decreased in the order of MF > AF > CP > LP ≈ QM, showing clear differences among land use types. This research shows that soil carbon and nutrient contents are significantly different across land use types, and it suggests that the horizontal and vertical distribution properties of carbon and nutrients by land use type need to be considered to accurately predict amounts of fixed carbon and nutrients during the transition of farmland to forest.

ABSTRACTBiochar has been used for soil improvement in agriculture; however, there are few studies of its uses in forestry. The purpose of this study was to investigate the effects of biochar, made from diverse feedstocks on the growth and chlorophyll content of Zelkova serrataseedlings, to identify optimal feedstocks in a containerized seedling production. Five resources were used for biochar: woodchips of Pinus densifloraand Quercus acutissima; cones of Pinus koraiensis; rice husks; and crab shells. The biochar was mixed with growing medium by 20% in volume and two levels of fertilization were applied. The height and root collar diameter of Z. serratatreated with wood chips of P. densifloraand Q. acutissimaand rice husk were each significantly greater than those treated with pine cones and crab shells. The biomass responses and quality indexes were similar to those of height and root collar diameter. There were no significant differences in growth between fertilization levels. This study shows that biochar made from woodchips of P. densifloraand Q. acutissimaand rice husk can be substituted for growing medium by 20% in a containerized seedling production system.

ABSTRACTThe objective of this study was to investigate plant growth and nutrient uptake of Chamaecyparis obtusaseedlings with heavy fertilization treatment depending on previous fertilization experience. In a previous year, one-year-old Chamaecyparis obtusaseedlings were planted at a nursery with two levels of fertilization: the first group was fertilized with a mixed nitrogen–phosphorus (N-P) fertilizer of N 41.4 g m−2, P 18.3 g m−2and the second group was unfertilized as a control. After one year, seedlings of similar height and root diameter were planted into 30-l pots and underwent two treatments: no fertilization for control and heavy fertilization with Basacote® 80 g pot−1. In the control, the plants’ growth exhibited no differences according to previous fertilization experience; in the case of heavily fertilized plants, seedlings which had experienced previous fertilization showed a 29% increase in height and a 63% increase in above-ground biomass production than did seedlings with no fertilization in the previous year. The biomass allocation to below-ground was low for the heavily fertilized seedlings regardless of previous treatments. N and P concentrations of the seedlings, measured at the leaf and root, were irrelevant to previous fertilization, but were higher in the heavily fertilized plants. This study suggests that previous fertilization experience at the nursery stage may reduce the stress induced by initial heavy fertilization during out-planting.

Soil nutrient management is necessary to maintain the constant productivity of nursery systems as well as good quality soil. This study investigated the effects of organic manure and chemical fertilizer treatments on growth performance and soil and tissue chemical properties. Two-year-old yellow poplar (Liriodendron tulipiferaL.) seedlings were treated with an organic manure (1000 g/m2; mixture of poultry manure, cattle manure, swine manure, and sawdust), nitrogen–phosphorus–potassium (NPK) chemical fertilizer (urea, 30 g/m2; fused superphosphate, 70 g/m2; potassium chloride, 15 g/m2), and organic manure plus NPK chemical fertilizer. Control seedlings were left untreated. Growth of seedlings, soil properties, and nutrient concentrations were measured to compare the treatments. Organic manure significantly increased the soil pH and the concentrations of nitrogen, available phosphorus, exchangeable potassium, calcium, and magnesium. In contrast, the NPK chemical fertilizer decreased the soil pH and exchangeable calcium concentration, did not affect the soil concentrations of nitrogen and magnesium, and increased the concentrations of available phosphorus and exchangeable potassium. Fertilization treatments increased the seedling height and root collar diameter by 21% and 29%, respectively, and the mean dry weight of the stems and leaves by 72% and 123%, respectively; but a synergistic effect of the organic manure and NPK fertilizer was not observed. Compared to the effects of the fertilization treatments on the soil properties, the effects on nutrient concentrations in the leaves, stems, and roots were relatively small. These findings indicate that organic manure derived from livestock byproducts and sawdust can be utilized in seedling production systems.