• Korean Journal of Soil Science and Fertilizer
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• v.7 no.4
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• pp.215-220
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• 1974

The relation between yield or total dry matter yield and nitrogen, phosphorus, potassium or silica uptake was investigated according to simple or multiple correlation coefficients, and multiple regression equations. 1. Simple correlation coefficient was always higher with total dry matter yield than with grain yield and highest with N in no nitrogen (0-6-8) or no fertilizer (0-0-0) plot, with P in no phosphorus plot (10-0-8) but lowest with K in no potassium plot (10-6-0). 2. Multiple correlation coefficient was always higher than simple correlation and the same is true with including Si as one more variation. There was clear trend that multiple correlation coefficient was highest in no fertilizer plot and lowest in no potassium plot. 3. Simple correlation coefficient with P was higher in the warm year in which P uptake and fertilizer-P use efficiency were higher while it with K was higher in the cool year in which K uptake and fertilizer-K use efficiency were higher. Nitrogen and silicate followed potassiuum. But partial regression coefficients of N. P. K and Si with yield were mostly significant only in the warm year. 4. Partial regression coefficient of K was negative in many cases with yield but significant positive value with total dry matter yield. 5. Partial regression coefficients of N. P and K were decreased when Si was included and the decrease was great in P. 6. With the increase of nitrogen fertilizer level partial regression coefficient was increased in N but decreased in P, and no consistency in K or Si. 7. According to single or multiple correlation coefficients and partial regression coefficients the contribution of nutrient to grain yield appears to be in the order of N > Si > P > K and to total dry matter yield in the order of N > K > Si > P, indicating that N is the main factor and others are closely related to each other throughout to N. The superiority of N was also proved by frequency pattern of relative yield.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1022-1026
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• 2012

To evaluate the application level of expeller cake fertilizer (ECF), we have investigated soil chemical properties, leaf mineral contents and yield of red mustard in plastic film greenhouse. Four levels of fertilizer were applied as 50% (ECF 50), 75% (ECF 75), 100% (ECF 100) and 150% (ECF 150) by base $1,848kg\;kg^{-1}$ of ECF. In 2010, red mustard was planted on April 28 in silt loam soil and harvested on July 7. Commerical yields were measured 12 times from May 14 to July 7. Electrical conductivity ($3.40{\sim}3.54dS\;m^{-1}$), available $P_2O_5$ ($580{\sim}618mg\;kg^{-1}$) and exchangeable cations ($K^+$, $Ca^{2+}$ and $Mg^{2+}$) were tended to increase by the application of ECF. However, the range of those was not so big increasing amount. The content of T-N, K, Ca and P of red mustard leaves was $63.2{\sim}66.4g\;kg^{-1}$, $55.1{\sim}56.4g\;kg^{-1}$, $8.6{\sim}9.5g\;kg^{-1}$ and $5.7{\sim}6.3g\;kg^{-1}$, respectively. The nitrogen utilization rate of red mustard was 38~52%, and it was decreased with increased application of ECF. The yield of red mustard was 13,670 to $14,460kg\;ha^{-1}$ on the basis of application amount of ECF and the yield did not increased in spite of increased ECF. The optimum dose of application of ECF for cultivation of red mustard was from $924kg\;ha^{-1}$ (ECF 50) to $1,386kg\;ha^{-1}$ (ECF 75). Environment-friendly and economical amount of applied fertilizer is more important than yield for cultivation of red mustard.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.194-199
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• 2011

This study was conducted to evaluate fertigation effects of pig slurry (PS) and chemical fertilizer (CF) in cucumber by investigating the growth and yield, nutrient content and uptake, nutrient use efficiency, and soil characteristics in greenhouse cultivation. The cropping patterns of cucumber were semi-forcing culture and retarding culture, and the experiment involves four treatments: No fertilizer (NF), $26mg\;L^{-1}$ and $52mg\;L^{-1}$ of N application by slurry composting biofiltration liquefied fertilizer (SCBLF), and $52mg\;L^{-1}$ of N treatment by chemical fertilizer. The difference on the plant height of cucumber between SCBLF and CF treatments was no significant, but fresh weight and dry weight of stem and root were higher in $26mg\;L^{-1}$ SCBLF treatment. The Ca content of the leaf was lower in the treatments of SCBLF and the K content of the root was lower in the $52mg\;L^{-1}$ CF treatment. The Ca content of the stem was lowest in the $52mg\;L^{-1}$ CF treatment and the mineral content of the fruit showed no significant difference. In case of semi-forcing culture, the gross yield was lower in the $52mg\;L^{-1}$ CF treatment and the yield of unmarketable fruit was lower in the SCBLF treatments. The nutrient use efficiency of cucumber is as follows: K (8.3 ~ 30.9%), N (4.2 ~ 13.0%), P (1.9 ~ 2.0%). The SCBLF treatments showed higher figure in the soil pH than that of the CF treatment, while EC and the content of $NO_3$-N were higher in the CF treatment than the former. The content of exchangeable K was higher in the plot treated with $52mg\;L^{-1}$ SCBLF, and there were no significant differences in the content of Ca and Mg between the treatments. In conclusion, it is suggested that the application of liquefied manure made from pig slurry may be able to replace the use of chemical fertilizer in nitrogen and potassium.

• International Journal of Industrial Entomology and Biomaterials
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• v.40 no.2
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• pp.41-50
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• 2020

Vermicompost, manure, compost and organic fertilization are ecofriendly. Nowadays, many products resulted from sericulture consumed by humans such as mulberry leaves, fruits, mulberry tea, silk and natural silk cosmetics. Soil applications of three treatments with vermicompost (0.5, 1 and 2 tons per 0.42 hectare) and recommended rate of mineral fertilizers of nitrogen phosphorus potassium were used for investigation. Impact of fertilization on mulberry plant traits of moisture, number of shoots/tree, total shoots length/tree, number of leaves/shoot, number of leaves/ (100g), leaf yield/tree and leaf yield of fadden/season were recorded. In addition the effect of fertilization on larval and cocoon characters of young instar duration, fifth instar duration, total larval duration, larval mortality percentage, weight of third instar larvae, weight of fourth instar larvae, weight of fifth instar larvae, fresh cocoon weight, fresh shell weight, pupae weight, cocoon shell ratio, silk productivity, cocooning percentage, pupation ratio, number of cocoons/ liter, crop cocoons by number, crop cocoons by weight, fecundity and fertility. Using vermicompost treatment was enhancing plant characters. Treatments of V₃, V₂ and V₁ were shortage young, fifth and larvae durations. Mostly feeding silkworm during the whole larval duration on treated mulberry leaves with vermicompost improving the traits average. Using vermicompost for fertilization by rate of V₃ and V₂ is better than others for cocoon characters for females and males.V₃ and V₂ of vermicompost per 0.42 hectare is recommended for rearing mulberry silkworm instead of mineral fertilization.

• Korean Journal of Plant Resources
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• v.35 no.2
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• pp.192-200
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• 2022

Nitrogen is the most essential macronutrient for the growth of fruit trees and is important factor determining the fruit yield. In order to produce high-quality fruits, it is necessary to supply the appropriate nitrogen fertilizer at the right time. For this, it is a prerequisite to accurately diagnose the nitrogen status of fruit trees. The fastest and most accurate way to determine the nitrogen deficiency of fruit trees is to measure the nitrogen concentration in leaves. However, it is not easy for citrus growers to measure nitrogen concentration through leaf analysis. In this study, several machine learning models were developed to classify the nitrogen deficiency based on the concentration measurement of mineral nutrients in the leaves of tangor Shiranuhi (Citrus unshiu × C. sinensis). The data analyzed from the leaves were increased to about 1,000 training dataset through the bootstrapping method and used to train the models. As a result of testing each model, gradient boosting model showed the best classification performance with an accuracy of 0.971.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.6
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• pp.399-407
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• 2008

Importance of climate change and its impact on agriculture and environment has increased with a rise of greenhouse gases (GHGs) concentration in Earth's atmosphere, which had caused an increase of temperature in Earth. Greenhouse gas emissions such as methane($CH_4$) and nitrous oxide($N_2O$) in the field need to be assessed. GHGs fluxes using chamber systems in the fields(2004~2005) with pepper cultivation were monitored at the experimental plots of National Academy of Agricultural Science(NAAS), Rural Development Administration(RDA) located in Suwon city. $N_2O$ emission during pepper growing period was reduced to 74.0~82.1% in sandy loam soil compared with those in clay loam soil. Evaluating $N_2O$ emission at different levels of soil water conditions, $N_2O$ emission at -50 kPa were lowered to 13.2% in clay loam soil and 40.2% in sandy loam soil compared with those at -30 kPa. $CH_4$ emission was reduced to 45.7~61.6% in sandy loam soil compared with those in clay loam soil. Evaluating $CH_4$ at different levels of soil water conditions, $CH_4$ emission at -50 kPa was lowered to 69.6% in clay loam soil and 55.8% in sandy loam soil compared with those at -30 kPa. It implied that -50 kPa of soil water potential was effective for saving water and reducing GHG emissions. From the path analysis as to contribution factors for $N_2O$ emission, it appeared that contribution rate was in the order of mineral N(51.2%), soil temperature (25.8%), and soil moisture content(23.0%) in clay loam soil and soil moisture content(39.3%), soil temperature (36.4%), and mineral N(24.3%) in sandy loam soil.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.107-113
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• 1987

A pot experiment was carried out using Seomjinbyeo to investigate the effects of some sulfur-containing substances on the growth of rice plants and on soil characteristics. The results are summarized as follows: 1. Soil pH in plots given the sulfur treatments was lower than that in the urea plot during the growing stages. Soil pH in plots given the mineral sulfur treatments was higher than that in the ammonium sulfate plot at the early growth stage of rice. However, as the stage of rice growth progressed, soil pH became similar. After the experiment, soil pH was higher, but the sulfur content of soil was lower in the urea plot compared with that in other sulfur plots. After the experiment, the sulfur content of soil in the ammonium sulfate plot was the lowest among the plots given the sulfur treatments. 2. Plant heights and the number of tillers of the rice plants in plots given the sulfur treatments were higher than those in the urea plot, specially in the number of tillers of the rice plants. 3. Nitrogen and sulfur contents of the tops of rice plants in plots given the sulfur treatments were slightly higher than those in the urea plot. nitrogen and sulfur contents in the ammonium sulfate plot were higher than those in plots given the mineral sulfur treatments at the early growth stage of rice. However, as the stage of rice growth progressed, those in plots given the mineral sulfur treatments were higher. 4. The chlorophyll content in the leaf blade at heading stage in plots given the gypsume and given the mineral sulfur treatments was significantly higher than that in the urea plot. The N/S ratio was negatively correlated with the chlorophyll content.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.1
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• pp.20-27
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• 1983

A series of laboratory experiment was conducted to find out the chemical composition, characterization of humic substances by physical and chemical methods and reaction of Na-pyrophosphate, $Ca(OH)_2$ and rice straw with albumin on the degradation of soil organic matter in the volcanic ask soils of the Jeju Island. Results obtained were summarized as follows: 1. The contents of organic matter, available silicon, active iron and aluminum concentration in volcanic ash the soils were remarkably higher but available phosphorous was comparatively lower than the mineral soils. In volcanic ash soil, the contents of potassium, calcium and magnessium were higher in upland soil than that of forest soil. The ratios of active $Al^{{+}{+}{+}}/Fe^{{+}{+}}$, C/P and $K/Ca^+$ Mg were apparently high in volcanic ash soils while that of $SiO_2$/O.M. was high in mineral soil. 2. The carbon/nitrogen ratio in humin, humic acid content in organic matter, and carbon contents of humin in total carbon of soil organic matter were apparently higher in the volcanic ash soils than in the mineral soils, The total nitrogen and fractions of acid or alkali soluble nitrogen were remarkably high in volcanic ash soils while mineralizable nitrogen ($NH_4$-N and $NO_3$) contents were high in mineral soils. 3. The values of K600, RF and log K were also higher in volcanic ash soils than those in mineral soils, and the absorbance in the visible range were high and color was dark in the soil of which humification was progressed Extracted humic acid from volcanic ash soil was less reactive to the oxidizing chemical reagent and was persistance to the acid or alkali hydrolysises. 4. The major oxygen-containing functional groups in humic substances of volcanic ash soils were phenolic-OH alcoholic-OH and carboxyl groups while those in mineral soil were methoxyl and carbonyl groups. 5. Absorption spectra of alkaline solution of humic acid ranged from 200 nm to maxima 500 nm. Visible spectra peaks of from humic substances in the visible region were recognized at 350, 420, 450 and 480 nm. Only one single absorbance peak was observed in the visible region at 362 nm for Heugag series and two absorbance Peak were also at 360 nm and 390 nm for Yeungrag series. 6. Evolution of carbon as $Co_2$ was increased with addition of Na-pyrophosphate in Namweon and Heugag series, and "priming effects" took place on the soil organic matter decomposition by addition of rice straw with albumin in Ido series.

• Korean Journal of Environmental Agriculture
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• v.30 no.1
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• pp.16-23
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• 2011

BACKGROUND: This study was conducted to investigate the effects of different organic treatments and a chemical fertilizer on the soil chemical, physical, and microbial properties in an organic pear orchard. METHODS AND RESULTS: Control was referred as a NPK chemical fertilizer (15N-9P-10K) and organic treatments included compost containing with oil cake, compost containing with humic acid, and compost containing with chitin substance. All treatments applied at rates equivalent to 200 g N per tree per year under the tree canopy in March 30 of 2008 and 2009. Soil bulk density, solid phase, liquid phase, and penetration resistance were not significantly different among the treatments. Organic treatment plots had greater organic matter, total nitrogen, potassium, and magnesium concentrations compared to control, and the nutrient concentrations were not consistently affected by the organic treatments. Microbial biomass nitrogen and carbon, dehydrogenase, acid-phosphatase, and chitinase activities overall increased from March to August. Organic treatments, especially compost containing with oil cake or chitin aicd, increased the microbial variables compared to control. CONCLUSION(s): All the organic treatments consistently stimulated soil biological activity. The consistent treatment effect, however, did not occur on the soil mineral nutrition as the trees actively taken up the nutrients during a growing season, which would have diminished treatment effects. Long-term study required for evaluating soil physical properties in a pear orchard.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.201-208
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• 1994

In order to study the effect of exsisting soil nutritional elements on the nitrogen uptake of sunflower, sorghum and black gram, pot experiment was carried out by using soils sampled from three different depths(0~20, 45~65, 90~110cm) of Brigalow soil in Australia. The results obtained were as follows : Dry matter and nitrogen uptake of corps were increased in the soil with higher nitrogen content. Chlorine uptakes of sunflower and sorghum were increased in the soil with higher nitrogen and lower chlorine contents, but that of black gram was done in the soil with higher contents of both elements. Ratios of nitrogen derived from applied fertilizer of three corps and fixed nitrogen of black gram were relatively low in the soil with higher content of soil nitrogen, but those derived from soil nitrogen were reverse. Recovery rates of applied nitrogen were relatively increased with higher cation uptakes of crops. Chlorine uptakes of sunflower and sorghum were positively correlated with each recovery of nitrogen, but that of black gram didn't show the trend. Recovery rate of applied nitrogen for black gram had significantly negative correlation with increase of soil chloride content.