• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s02
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• pp.1-12
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• 1989

The primary countermeasure for environmental stresses of crops grown in Korea would be to maintain top soil content of available B for upland crops and Si for low land rice in balance with other nutrient elements such as N, P and K, so as to maintain those nutrient balances in plants. Development of standard levels of elements in soils for balances uptake of those elements by plants are needed under the multi nutrient factor balance concept using the soil test results.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.3 no.1
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• pp.25-33
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• 1998

Temporal and spatial variations of nutrient elements (ammonia, nitrate, nitrite, phosphate and silicate) in surface seawater off the west coast of Korea were investigated during three periods of field survey aboard R/V Eardo of KORDI (May 1995 and June 1996) and a patrol vessel of the National Maritime Police (November 1995). In general, the concentrations of nutrient elements were lowest in June and highest in November except for ammonia that showed the lowest concentration in May and the highest in November. The results tell us that the development of thermocline and tidal front restricts riverine and benthic supply of nutrient elements to surface waters in June in the offshore regions of the study area which become nutrient-depleted due to phytoplankton bloom in spring. In late fall (November) the level of nutrient concentrations of the surface waters of the study area become high due to vigorous vertical mixing within the water column, which supplies nutrient-enriched bottom water to the surface waters.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.1039-1048
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• 2020

Food waste causes various economic losses and environmental pollution problems such as soil pollution and groundwater pollution. Food waste has been used as a resource in various forms and has been used mostly for feed and composting. This study compared microalgal nutrient medium (BG-11) with food waste compost to determine the possibility of using it as a culture medium. Scenedesmus quadricauda was isolated and cultured in an eutrophic reservoir and incubated for 3 days in distilled water before laboratory use. Food waste compost was produced in two food waste processing facilities, and hot water was extracted in the laboratory to be used for microalgae cultivation. The growth curve of the microalgae was analyzed based on the Chl-a concentration measured during the experiment, and the growth rate of the microalgae grown in the food waste compost was compared with the growth rate of those grown in the nutrient medium. Food waste compost showed a similar growth rate to that of the nutrient medium, and there was a difference depending on the manufacturing facility. The growth of microalgae in such food waste was further amplified when trace elements were added and showed better growth than that of the nutrient media. Particularly, when trace elements were added, the growth rate increased, and the growth period was further extended. Therefore, food waste compost can be sufficiently utilized as a microalgal culture medium, and if trace elements are added, it is considered that microalgae can be more effectively cultured compared to the existing nutrient medium.

• The Korean Journal of Ecology
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• v.26 no.6
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• pp.313-319
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• 2003

Dry weight loss and nutrient release from leaf litter for six tree species were studied using litter bag methods. The litter bags were incubated for f6 months on the forest floor in temperate deciduous forest in Mt. Cheonma, located at the middle part of Korean Peninsula. The changes in nutrient content and the rate of dry weight loss in leaf litter varied with litter types. The litter of Pinus densiflora showed the lowest rate of mass loss (k=0.33), nitrogen concentration (0.89%) and ash concentration (2.50%), while showed the highest C/N ratio (63.40). On the other hand, the litter of Acer pseudo-sieboldianum showed the fastest rate of mass loss (k=0.82), the highest nitrogen concentration (1.11%), and the lowest C/N ratio (49.40). During the decomposition, nitrogen, phosphorus and calcium in the leaf litters showed relatively slow decreasing pattern compared to other elements (carbon, potassium, magnesium, manganese and sodium), but potassium and sodium decreased at early stage of the decomposition for all leaf litters. Differences in annual decomposition rates of litter among species were consistent with the particular chemical characteristics of their leaf litters. The initial concentration of nitrogen was positively correlated with litter decomposition rate for six species, while litter decomposition rate of six species was negatively correlated with C:N ratio of initial leaf litters.

• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.249-254
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• 1999

The effects of various levels of Al concentration on growth, nutrient status and net photosynthetic rate of 2-year-old Pinus densiflora Sieb. et Zucc. seedlings grown in a nutrient culture solution were investigated. Al concentrations were added as aluminum chloride($AlCl_3$) at 0(control), 10, 30 and 60ppm to the nutrient culture solution. The nutrient culture solution was maintained at pH 4.0 by adding HCl or NaOH solution. The seedlings were transplanted into the nutrient culture solution and grown in a greenhouse for 90 days from May 8 to August 6, 1996. The treatment above 10ppm of Al concentrations induced a significant reduction on the dry weight growth of the seedlings. The relative growth rate(RGR), net assimilation rate(NAR) and net photosynthetic rate of the seedlings were reduced with increasing of Al concentrations in the nutrient culture solutions. This result suggests that reductions in the RGR and NAR of the seedlings were mainly due to the inhibition of net photosynthesis. In addition, the increase of Al concentrations in a nutrient culture solution decreased the concentration of essential mineral elements such as Ca and Mg in the needle of the seedlings. However, the concentrations of Al of each plant organ increased in the treatment above 10ppm of Al concentrations in the nutrient culture solutions. This result suggests that the increased Al concentration in the belowground part resulted from the decreased concentration of essential mineral elements in the aboveground part of the seedlings.

• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.1
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• pp.1-15
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• 2004

Due to recent scientific innovations in mulberry cultivation, leaf yield has been increased manifold. However, with successive leaf harvest, a quantum drop in leaf yield and quality has been noted. This inturn has affected the silkworm rearing and farmers suffered by the frequent crop failures. This is mainly due to nutrient deficiencies in mulberry leaf. Moreover, no complete information is available about hunger signs of nutritional disorders, analytical diagnosis and critical levels of nutrients required. The present paper, thus, may serve as an important nutrient guide for identification of hunger signs, leaf nutrients status under deficiency and critical levels of the elements namely N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn requirements for higher leaf yield and quality. The leaf nutrient status provided may help chemist for correcting the soil status. Besides, an integration of mulberry intercropping with legumes and applications of neem and castor oil cakes, VA-mycorrhizal inoculation, biofertilizer and vermicompost are suggested as integrated nutrient management for sustainable sericulture industry. Based on the information described in this paper, a model needs to be framed for maintaining continuous supply of nutrients to obtain desired quantity and quality of mulberry leaf for successful silkworm cocoon crop and increasing overall silk productivity.

• Journal of Korean Society of Forest Science
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• v.96 no.2
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• pp.214-221
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• 2007

The effect of nutrient availability and forest type on the nutrient turnover of fine roots is important in terrestrial nutrient cycling, but it is poorly understood. I measured nutrient turnover of hardwoods and softwoods at three well studied sites in the northeastern US: Sleepers River, VT; Hubbard Brook, NH; Cone Pond, NH. Significant differences in nutrient turnover by fine roots were observed among sites, but not between forest types. The magnitude of differences for each element ranged from 3 times for P and N to 8 times for Ca and Mg between sites. Smaller differences of 0.2 to 0.8 times were observed between forest types. In hardwoods, the Sleepers River 'new' site had $23kg\;ha^{-1}\;yr^{-1}$ Ca, $7kg\;ha^{-1}\;yr^{-1}$ Mg, and $16kg\;ha^{-1}\;yr^{-1}$ K turnover, owing to high root nutrient contents and turnover. Cone Pond had the highest turnover for Mn ($0.8kg\;ha^{-1}\;yr^{-1}$) and Al ($16kg\;ha^{-1}\;yr^{-1}$), owing to high nutrient contents. The Hubbard Brook hardwood site exhibited the lowest turnover of these elements. In softwoods, the variation in turnover of Ca, Mg, and K was lower than in hardwoods. The Hubbard Brook had the highest turnover for P ($1.6kg\;ha^{-1}\;yr^{-1}$), N ($31kg\;ha^{-1}\;yr^{-1}$), Mn ($0.4kg\;ha^{-1}\;yr^{-1}$), Al ($10kg\;ha^{-1}\;yr^{-1}$), Fe ($6.4kg\;ha^{-1}\;yr^{-1}$), Zn ($0.3kg\;ha^{-1}\;yr^{-1}$), Cu ($34g\;ha^{-1}\;yr^{-1}$), and C ($1.1Mg\;ha^{-1}\;yr^{-1}$). Root Ca turnover exponentially increased as soil percentage Ca saturation increased because of greater root nutrient contents and more rapid turnover at the higher Ca sites. These results imply that nutrient inputs by root turnover significantly increase as soil Ca availability improves in temperate forest ecosystems.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.3
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• pp.192-200
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• 2005

This study was conducted to investigate inorganic nutrient contents in spur leaf and shoot leaf of 'Niitaka' pear during the growing season and leaf inorganic nutrient contents as influenced by meteorological elements. The contents of N, P, K, and Mg were decreased in spur leaf during their vegetative growth, while Ca and Mn increased. The contents of N, P, K, Mg, and Fe showed no differences between spur leaf and shoot leaf. However Ca, Mn, Zn, and Cu contents were higher in spur leaf than those in shoot leaf, but B content was lower in spur leaf than those in shoot leaf. The content of N in shoot leaf was positively correlated with mean temperature, whereas negatively correlated with maximum temperature. The content of P in spur leaf was negatively correlated with maximum temperature. The content of Ca in spur leaf was negatively correlated with mean temperature, whereas positively correlated with maximum and minimum temperature. The contents of Mg and B in shoot and spur leaf were positively correlated with mean temperature, whereas negatively correlated with maximum and minimum temperature. The contents of Ca and Mn showed significant differences between spur leaf and shoot leaf at mid-July to early August. These results suggest that sampling is important to distinguish between spur leaf and shoot leaf for diagnosis of nutrient conditions in pear trees.

• Mass Spectrometry Letters
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• v.11 no.4
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• pp.108-112
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• 2020

A certified reference material (CRM) for the analysis of nutrient elements in an edible mushroom (Ganoderma lyceum) powder has been developed (KRISS CRM 108-10-011). The mass fractions of calcium (Ca), iron (Fe), and zinc (Zn) were measured by isotope dilution inductively coupled plasma mass spectrometry (ID ICP/MS). To dissolve the fungi cell wall of mushroom consisted of chitin fibers, sample preparation method by single reaction chamber type microwave-assisted acid digestion with acid mixtures was optimized. The mean measurement results obtained from 12 sample bottles were used to assign as the certified values for the CRM and the between-bottle homogeneities were evaluated from the relative standard deviations. The certified values were metrologically traceable to the definition of the kilogram in the International System of Units (SI). This CRM is expected to be used for validation of analytical methods or quality control of measurement results in analytical laboratories when they determine the mass fractions of elements in mushroom or other similar samples.

• Journal of Bio-Environment Control
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• v.6 no.1
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• pp.27-33
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• 1997

This experiment was carried out to investigate the effects of limited nutrient supply during 21 days before and after pollination stage on the growth, fruit quality and nutrient uptake of muskmelon in rockwool culture. Muskmelon, cv. Earl's Favorite seeds sowed on rockwool cube and transplanted on rockwool slab($90\times15\times7.5cm$) when 2 to 3 true leaf appeared on Sep. 6, 1991. Three kinds of nutrient composition recommended by Shizuoka university, combinated with the composition of Otsuka house A and composition Shizuoka III. One half of calcium nitrate(Ca(NO$_3$)$_2$.4$H_2O$) for limiting nitrogen supply during 21 days was treated and then fertigated the nutrient composition recommended by Shizuoka university up to harvest time. Trickling nozzles(Netafim Co. Israel) were used for fertigation of nutrient solution and noncirculating system was employed. Temperature was maintained $18^{\circ}C$ in night but 23 to $25^{\circ}C$ for 10 days after pollination for softening the fruit. The drainage ratio of nutrient solution was adjusted 20 to 30 percent. Fertigated and drained amount, and the pH and EC of nutrient solution were recorded. The concentrations of mineral elements including N, P, K, Ca, and Mg were analyzed and compared among treatments. In both autumn and winter cultivation, the limitation of nutrient supply by adjustment of nutrient composition(NO$_3$-N : 8meㆍ$\ell^{-1}$) caused the nutrient deficiency in muskmelon plant due to the limited nutrient supply. After pollination nutrient limitation by the lowering the nitrate retarded the over thickening of upper leaves of muskmelon but plant height and fresh weight of fruit were higher in the plot of nonlimited nutrient supply. The phenomena were attributed to the differences of the amount of nutrient uptake due to the limited time of nutrient solution, duration of nutrient supply and concentration of nutrient solution. These results suggested that increasing nutrient supply in the pollination stage was favorable for better appearance of fruit and improving fruit quality. Further trials would be required for the incre-ment of sugar degree of muskmelon grown in rockwool.