• The Korean Journal of Ecology
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• v.6 no.2
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• pp.90-97
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• 1983

Seasonal changes of the soil nutrient contents and aboveground biomass, relationship between the soil nutrients and the productivity, and the net efficiencies of solar energy conversion were studied in two reeed communities (Phragmites communis Trin.) at the salt marsh in the estuary of the Sumjin-River from April 30 to October 9, 1981. The inorganic nutrients such as exchangeable sodium and potassium of soil were decreased during growing season. The amounts of organic matter, exchangeable sodium and potassium, total nitrogen, and available phosphorus in stand $\prod$ were much more than those of stand $\coprod$ . Productivity of Phragmites communis was positively correlated with the soil nutrients such as available phosphorus, exchangeable potassium and total nitrogen. The maximum dry matter productions of the aboveground parts in stand $\prod$ stand $\coprod$ were $ 1, 120g/m^2; and; 843g/m^2$ in August, and the net coversion efficiencies of PhAR based on growing season (April to September) were 1.77% and 1.33%, respectively.

• Journal of Forest and Environmental Science
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• v.34 no.1
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• pp.12-23
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• 2018

Quantitative information on biomass and available nutrients are essential for developing sustainable forest management strategies to regulate atmospheric carbon. An attempt was made at Chilapatta Reserve Forest in Duars region of West Bengal to quantify its above and below ground carbon along with available "N", "P" and "K" in the soil. Stratified random nested quadrats were marked for soil, biomass and litter sampling. Indirect or non-destructive procedures were employed for biomass estimation. The amount of these available nutrients and organic carbon quantified in soil indicates that the forest soil is high in organic carbon and available "K" and medium in phosphorus and nitrogen. The biomass, soil carbon and total carbon (soil C＋C in plant biomass) in the forest was 1,995.98, 75.83 and $973.65Mg\;ha^{-1}$. More than 90% of the carbon accumulated in the forest was contributed by the trees. The annual litter production of the forest was $5.37Mg\;ha^{-1}$. Carbon accumulation is intricately linked with site quality factors. The estimated biomass of $1,995.98Mg{\cdot}ha^{-1}$ clearly indicates this. The site quality factor i.e. tropical moist deciduous with optimum availability of soil nutrients, heavy precipitation, high mean monthly relative humidity and optimum temperature range supported luxuriant growth which was realized as higher biomass accumulation and hence higher carbon accumulated.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.732-739
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• 2009

Pig slurry is a good soil amendment not only because of its high organic matter content, but also because of its ability to provide various nutrients. The objective of this study was to estimate the influence of raw and processed pig slurry application on pot soil over chemical fertilizer and non-amended control soil. Change in the chemical parameters (pH, organic matter (OM), organic carbon (OC), macro and micronutrients) and microbial mass of the treated soils were monitored over 30 to 90 days. Pot soil was treated with the recommended dose of pig slurry and chemical fertilizer, and was sampled after 30, 60 and 90 days of incubation. The least significanct difference (p<0.05) was observed on Fe, Cu, Zn, available P and K between treatments. All treatments increased N, P and K content and microbial mass of soil over control soil. Interestingly, no significant effects were detected on OM, OC, total bacteria, actinomycetes and fungi mass in soil irrespective of treatments given. However fungal and bacterial counts, as well as available nutrients, were found to be higher in processed slurry (PS)-treated soil compared to other soils. In general a significant correlation existed between the fungal count and OM, OC, Zn, T Kjeldahl N (TKN), available P and K of soil. A strong negative correlation was observed between pH and Fe in soil. This study clearly demonstrated that the use of processed manure as a fertilizer could be a key for sustainable livestock agriculture.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.328-335
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• 2023

For appropriate nutrient management and enhanced plant growth, soil sensors which reflect soil nutrient levels are required. Because there is no available sensor for nutrient monitoring, electrical conductivity (EC) sensor can be used to evaluate soil nutrient levels. Soil nutrient management using EC sensors would be possible by understanding the relationship between sensor EC values and soil temperature, moisture, and nutrient content. However, the relationship between soil sensor EC values and plant available nutrients was not investigated. Therefore, the objectives of the study were to evaluate effect of different amount of urea on soil EC monitored by sensors during pepper and broccoli cultivation and to predict the plant available nutrient contents in soil. During the cultivation period, soil was collected periodically for analyzing pH and EC, and the available nutrient contents. The sensor EC value increased as the moisture content increased, and low fertilizer treated soil showed the lowest EC value. Principal component analysis was performed to determine the relationship between sensor EC and available nutrients in soil. Sensor EC showed a strong positive correlation with nitrate nitrogen and available Ca. In addition, sum of available nutrients such as Ca, Mg, K, P, S and N was positively related to the sensor EC values. Therefore, EC sensors in open field can be used to predict plant available nutrient levels for proper management of the soil.

• The Korean Journal of Ecology
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• v.19 no.5
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• pp.375-383
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• 1996

Effects of forest fire on soil nutrients in pine forests were studied in Dosong, Kangwon Province in Korea. Soil samples were collected from burned sites and unburned sites (control) at Kusungri, Sampori and Wunbongri. Soil pH in burned sites was higher than that in unburned sites. Soil organic matter did not differ significantly between the burned and unburned sites. Concentrations of available phosphorus in burned soils were about 3 times higher than those in unburned sites. Also, concentrations of ammonium nitrogen were markedly increased in burned sites contrary to those of nitrate nitrogen. Total nitrogen, however, showed no significant difference between the sites. Concentrations of cations, calcium and magnesium, in burned sites were also significantly increased. Thus, even though forest fire removed the aboveground biomass of pine forests, inorganic nutrients added from ash may play a great role for growth of sprouts and seedlings after forest fire.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.496-501
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• 2005

SWAT2000 model directly estimate the loading of water, and nutrients from land areas in a watershed. it allows to add nutrient loading from the point sourece like a sewage treatment plant and it also has a GIS interface which can easily see the spatial relationship between subbasins. For better assessment of nutrients loading to KEUMGANG estuary, SWAT2000 model applied to KEUMGANG estuary watershed. Model calibration and verification was firstly poerformed at Gongju site duing the period $1999{\sim}2003$. $R^2$ value was 0.96 for streamflow, 0.94 for T-N load and 0.52 for T-P load. The accuracy of the model at Gongju site suggest that the SWAT2000 can be available to estimate streamflow, Nutrients loading to the KEUMGANG estuary.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.97-100
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• 1992

Locally available milk mix, coconut meal, cassava root meal, cassava leaf meal, maize, meat meal, fish meal, rice bran, rice polishings, wallow, molasses and coral sand in Fiji were analysed for proximate components, gross energy and mineral contents. The results obtained indicated typical and variable amounts of nutrients in these materials. On the basis of their nutrient contents, the potential usefulness and weaknesses of the various feed materials are discussed with specific reference to the formulations of diets for livestock and poultry in Fiji based on these locally available feed materials.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.5
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• pp.563-566
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• 1996

Five crossbred heifers(Holstein Friesian $\times$ Hariana) aged about one year and average body weight 157.0 kg were used to observe the effect of UMLD with restricted amount of wheat straw (500 g/100 kg body weight) on body weight gain and nutrient utilization. After seven months feeding the animals were switched to a revival diet consisted of wheat straw and concentrate mixture, for an additional six months. Fortnightly body weights were recorded and metabolism trials were conducted at the end of the two experimental periods. Results indicated that the average daily gain were 57.0 and 413.3 g in two feeding systems. This showed a sub-optimum growth during UMLD feeding which was compensated when good quality revival diet was available. Though, the nutrients intake were significantly (p < 0.01) lower in UMLD feeding period as compared to revival diet feeding, but digestibility of all the nutrients were alike statistically. It can be concluded that UMLD with restricted amount of wheat straw can be fed as scarcity feed for a short period, without causing irreparable loss to the animals, provided sufficient feed nutrients are available after the scarcity period.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.6
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• pp.976-987
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• 1999

The process of weaning, no matter how carefully managed, results in changes in the gut of the pig that make it more susceptible to digestive upset, diarrhea and impaired appetite. The objective in developing feeding programs is to recognize these unique needs and facilitate a smooth transition to a dry feed. How well this is accomplished, has a significant impact on future performance. This paper provides a review of recent research on the nutrients required by early weaned pigs and examines what feedstuffs are available to provide those nutrients in a form that can be best utilized by the early weaned piglet.

• Journal of Korean Society of Forest Science
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• v.85 no.4
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• pp.656-666
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• 1996

Aspen demand has increased recently in the Great Lakes region in the United States. Since aspen has moved into the region in late 1800's, its growing stock has increased so as to change forestry industry of the Lake States. Intensive timber harvesting and biomass removal may cause nutrient depletion, especially on nutrient-poor sites. Forest nutrients and nutrient cycling were investigated in aspen stands of 7-10, 27-33, and 41-42 year-old growing on sandy soils in Minnesota. Nutrients added to the aspen stands by atmospheric deposition and soil weathering were efficiently absorbed and stored in the tree biomass. Aboveground biomass increased from $24.4t{\cdot}ha^{-1}$ at young stands to $139.2t{\cdot}ha^{-1}$ at mature stands. Nutrients accumulated in the tree biomass showed same magnitude of difference. Nutrients added to the site through atmospheric deposition were in the order of Ca, N, K, Mg, and P. Annual litterfall was greater in older stands. However, the amount of nutrients returned by litterfall was not significantly different among stand ages due to the greater nutrient contents in the litterfall of young stands. Litter decomposition and nutrient release rates were greater at young stands than at older stands. Likewise, nutrient availability was higher in young aspen stands and became lower as the stands grew older. Nutrient leaching loss was minimal at all stand ages. Soil N mineralization was greater at young stands than at older stands. Nutrient cycling process was facilitated in young aspen stands with an increased level of available nutrients, Based on the estimations of nutrient balance and nutrient removal by harvesting, Ca was the most critical element which was likely to be depleted if aspen stands are intensively harvested with short rotations.