Byung Bae Park

Measured and modelled differences in nutrient concentrations between rhizosphere and bulk soil in a Norway spruce stand

The gradient in soil characteristics from the bulk soil to the root surface is important to roots and to the organisms that live in the rhizosphere. Our ability to measure ion concentrations at the root surface is extremely limited, and models are largely untested. We used data from a well studied Norway spruce stand in SW Sweden to compare the measured difference in nutrient concentrations between rhizosphere and bulk soil with the difference predicted by a steady-state simulation model based on ecosystem budgets of nutrient uptake. The simulation model predicted depletion of NH4, Ca, Mg, K in the rhizosphere, which shows that budgeted uptake rates were greater than the mass flow of bulk solution towards the root. In plots treated with ammonium sulphate, the model predicted an accumulation of S in the rhizosphere. In contrast, the observed rhizosphere concentrations were generally enriched in nutrients, relative to bulk soil. Collecting rhizosphere soil adhering to root surfaces may not be an appropriate method for describing the concentration gradient around the root. In addition, the simulation model omits some processes affecting conditions in the rhizosphere that are important to explaining nutrient uptake.

Wood ash effects on soil solution and nutrient budgets in a willow bioenergy plantation.

The management of wood ash is an important factor in the environmental and economic analysis of wood burning. Wood ash can be applied to energy crops as a fertilizer, which can help replace nutrients removed during harvest. The objectives of this study were to examine the temporal and spatial dynamics of nutrient elements applied in wood ash to an intensively cultured, short-rotation willow bioenergy system. Wood ash was applied at the rates of 10 and 20 Mg ha−1 yr−1 to coppiced willow, Salix purpurea, clone SP3, from 1992 to 1994. The relative abundance of nutrients in applied wood ash was Ca > K > Mg > P > N. There was little effect of wood ash on N or P concentrations in soil solution measured at 20 and 40 cm depth. Soil solution concentrations of base cations were elevated in the last two years of the study by 30 to 90%, depending on the element and treatment, in plots receiving wood ash. Wood ash treatments had little influence on foliar leaching. Wood ash treatment also had few significant effects on willow growth or on the contents of N, P, K, Ca, and Mg in foliage and stems. The addition of P, K, Ca, and Mg in wood ash was more than enough to compensate for harvest removals and leaching losses. This study demonstrated that wood ash can supply most nutrients removed during harvest in willow plantations, with the exception of N, without adverse effects on groundwater or vegetation.

Identifying roots of northern hardwood species: patterns with diameter and depth

Forest canopies are often stratified by species; little is known about the depth distribution of tree roots in mixed stands because they are not readily identified by species. We used diagnostic characteristics of wood anatomy and gross morphology to distinguish roots by species and applied these methods to test for differences in the rooting depth of sugar maple (Acer saccharum Marsh.), American beech (Fagus grandifolia Ehrh.), and yellow birch (Betula alleghaniensis Britt.) in two northern hardwood forests. We also distinguished hobblebush (Viburnum lantanoides Michx.) and white ash (Fraxinus americana L.) roots. Analysis of plastid DNA fragment lengths confirmed that 90% of the roots were correctly identified. The vertical distribution of fine roots of these species differed by 2-4 cm in the median root depth (P = 0.03). There was a significant difference in the distribution of roots by size class, with fine roots (0-2 mm) being more concen- trated near the soil surface than coarser roots (2-5 mm; P = 0.004). The two sites differed by <2 cm in median rooting depths (P = 0.02). The visual identification of roots for the main tree species in the northern hardwood forest allows spe- cies-specific questions to be posed for belowground processes.

Minimizing nutrient leaching and improving nutrient use efficiency of Liriodendron tulipifera and Larix leptolepis in a container nursery system

Fertilization is essential to seedling production in nursery culture, but excessive fertilization can contaminate surface and ground water around the nursery. The optimal fertilization practice is that which maximizes seedling growth and minimizes nutrient loss. We tested three fertilization strategies: (1) constant fertilization (2) a three-stage rate, and (3) exponential fertilization on Liriodendron tulipifera and Larix leptolepis containerized seedlings. Growth performance, nutrient uptake, and nutrient loss in leaching were measured. Height, root collar diameter, and dry weight of both species were not significantly different among treatments even though the nutrient supply of the exponential treatment was half that of the constant and three-stage treatments. Generally, nutrient losses in leached solutions were higher in constant and three-stage than the exponential treatment. Nutrient use efficiency was calculated as the ratio of the nutrient content of the seedlings to the amount of nutrient applied to the containers. The nitrogen use efficiency in the constant, three-stage, and exponential treatments was 63, 61, and 85% for yellow poplar, respectively, and 35, 30, and 53% for larch. Similar results were obtained for phosphorus and potassium. Thus, the exponential treatment had the highest nutrient use efficiency as well as the least nutrient loss. Adjusting fertilization rates can reduce soil and water contamination around the nursery without compromising growth performance, which reduces both producer’s investments and environmental impacts.

The effects of biochars on the growth of Zelkova serrata seedlings in a containerized seedling production system

ABSTRACT Biochar 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 serrata seedlings, to identify optimal feedstocks in a containerized seedling production. Five resources were used for biochar: woodchips of Pinus densiflora and 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. serrata treated with wood chips of P. densiflora and Q. acutissima and 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. densiflora and Q. acutissima and rice husk can be substituted for growing medium by 20% in a containerized seedling production system.

The effects of organic manure and chemical fertilizer on the growth and nutrient concentrations of yellow poplar (Liriodendron tulipifera Lin.) in a nursery system

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 tulipifera L.) 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.

Biochar effects on the seedling quality of Quercus serrata and Prunus sargentii in a containerized production system

Abstract Biochars 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 serrata and Prunus sargentii in 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. serrata and by 19.9% in P. sargentii. Our results suggested that charcoal can be applied to improve seedling quality in the containerized Q. serrata and P. sargentii seedling production system.

Characteristics of soil carbon and nutrient stocks across land use types in a forest region of central Korea

ABSTRACT Land use change greatly affects the carbon cycling of the Earth. Soil carbon and nutrient stock distributions were identified in the five land use types: Quercus spp. mixed forest (QM); Larix leptolepis plantation (LP); Castanea crenata plantation (CP); Malus pumila orchard (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.

Torrefied wood effects on the seedling quality of Zelkova serrata and Fraxinus rhynchophylla in a containerized production system

ABSTRACT Biochar 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 serrata and Fraxinus rhynchophylla seedling 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 serrata and Fraxinus rhynchophylla seedling production systems.

Effects of cumulative fertilization pattern on growth and nutrient concentrations of Chamaecyparis obtusa seedlings

ABSTRACT The objective of this study was to investigate plant growth and nutrient uptake of Chamaecyparis obtusa seedlings with heavy fertilization treatment depending on previous fertilization experience. In a previous year, one-year-old Chamaecyparis obtusa seedlings 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−2 and 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.