• Korean Journal of Soil Science and Fertilizer
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• v.26 no.3
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• pp.172-180
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• 1993

Chemical properties of the soils were surveyed in the field of vinyl houses concentrated in the area of Bunpyong-dong and Shinchon-dong of Cheongju, Chilgeum-dong of Chungju and Gageum-myeon of Jungweon-gun. Chungcheongbuk-do province. 1. Content of chemical component of the soil in the vinyl house was higher than in open field. In more than half of the vinyl house soils surveyed, electric conductivity was more than 4.0 mmhos/cm and available phosphate was more than 1,000ppm. 2. Contents of availble phosphate and exchangeable potassium were increased with years of cultivation and their content of accumulation in soil were in the order of Bunpyong-dong>Shinchon-dong>Gageum-myeon>Chilgeum-dong. While their mobility was comparatively low. 3. $NO_3$-N content was remarkably higher in vinyl house soil and the older in cultivation made $NO_3$-N content higher same as the case of available phosphate content. However easy leaching of $NO_3$-N through soil profile is expected due to the fact that $NO_3$-N content was rapidly decreased by removal of polyethylene film cover from the frame of house after harvest of crops. 4. It is a tendency that various chemical contents of vinyl house soils wer higher in 1992 than in 1988~1990, especially much higher from the area of Bunpyong-dong and Shinchon-dong of Cheongju. 5. Salt accumulation in vinyl house soil has been increased with continuing cultivation. Therefore amount of fertilizer application should be controlled in order to avoid salt toxicity, quality deterioration for crop and salt contamination of ground water.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.285-294
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• 1999

Changes of chemico-physical properties and mturitiy during pig manure composting were analysed using three kinds of bulking agents with rice hull(T1), rice hull and extruding hull mixture (T2, 1:1, v/v), and extruding hull(T3). During composting process, temperature of T1, T2 and T3 were maintained over $50^{\circ}C$ for 31, 21, and 35 days respectively. Organic matter content of each treatment was decreased from 82.2%, 82.0%, and 82.8% to 70.5%, 68.9% and 69.7% and pH increased to 8.85, 9.91, and 8.80, respectively. Total nitrogen content of all treatments gradually decreased, but C/N ratio, phosphorous, and potassium content did not, show any changes during composting process. Both germination rate and early growth were tested using radish seeds for composting maturity. From those results, it was concluded that all treatments were stabilized after 45th day and extruding hull(T3) added compost was superior to others. The test of suppressive effect showed that all treatment have no effect against Fusarium oxysporum, Alternaria altemata, Botrytis cinerea. Compost supplemented with rice hull showed an inhibitory effect after 30th days, while compost supplemented with rice hull and extruding hull(T2) had an inhibitory effect during all period against Rhizoctonia solani. But treatment with extruding hull(T3) added compost did not have any inhibitory effect against Rhizoctonia solani. Only 63th samples in T1 and T2 treatment showed inhibitory effect against Colletoerichum gloeosporioides. However, T3 did not. Suppressive effect of extracts from 67 kinds of composts was investigated in vitro against plant pathogens, such as Fusauum oxysporum. Alternaria alternata, Colletotrichum gloeospoioides, Rhizoctonia solani, and Botrytis cinerea. Thirty two of them showed inhibitory effect against more than one phytopathogen, nine against one pathogen, four against two, six against three, six against four, and seven against five.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.732-738
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• 2015

Quality characteristics of Korean cabbage treated with red clay-processed materials (RCPM) were evaluated. Two different types of RCPM treatments including a control were applied for the cultivation of cabbage. General components, nutrients, antioxidant activities, textures, and sensory evaluation were assessed. For the nutrition components analysis, RCPM-treated cabbage showed higher contents of potassium and riboflavin along with lower content of sodium compared to the control. RCPM-treated cabbage exhibited higher total polyphenol contents than those of the control, indicating higher antioxidant activities. For the textural analysis under refrigeration over 4 weeks, RCPM-treated samples showed more stable textures based on higher hardness values than the control and RC. Results of this study indicate that RCPM would be of benefit to produce high-value added cabbage of premium quality.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.134-138
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• 2011

This study was conducted to evaluate the effects of seeding time of ryegrass+hairy vetch on the nutrient contribution and growth of the crops. in order to develop utilization of cover crops as an organic nutrient source in a pear orchard. The study was conducted at a diligent farmer in Boseong in Chonnam, and the both ryegrass and hairy vetch applied on 1) 27 September, 2) 15 October, 3) 8 November, and 4) 10 December of 2008 as a cover crop treatment. Sod culture was refereed as a control. Growth of ryegrass was not affected by seeding time, but hairy vetch had fewer leaf and shoot number as seeding time advanced from September to December, and the similar trend was observed for the dry weight of the crops by seeding time. Seeding of cover crop on September was 2.6 times greater dry weight than those of the sod culture (362 kg/10a). Higher N concentration in cover crops occurred on early seeding time, and estimated N contribution from the cover crops was 16.9 kg/10a, which was 2.6 times greater than those of sod culture. $P_2O_5$ production from the cover crops was the greatest on seeding of October, and $K_2O$ production increased at earlier seeding time.

• Korean Journal of Environmental Agriculture
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• v.23 no.1
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• pp.7-14
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• 2004

This study was conducted to investigate the effect on agricultural environment and crop productivity by different amount of applied fertilizer in consideration of irrigation water quality. N, P and K contents of irrigation water used in this experiment were 6.16, 0.26 and 9.37 mg/L, respectively. N, P and K Concentrations of runoff water were lower than those of inflow water during rice cultivation. N, P and K Concentrations of ponded and percolated water were changed according to the amount and time of applied fertilization. During rice cultivation in paddy soil, nitrogen balance was closed to 0 in SFT 50% (50% level of soil testing fertilization), 0.14 kg/ha, but it was 95.3 kg/ha in CF (conventional fertilization) treatment In SW 50% and STF (soil testing fertilization) treatment yield of perfect rice was not greatly different as compared with CF treatment due to the superiority of ripening rate, 1,000 grains weight and milling characteristics. Mechanical paratability of rice was excellent in NF (non fertilization) treatment, STF 50% treatment showed higher in nutrient availability and fertilizers use efficiency than other treatments.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.1
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• pp.135-143
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• 2018

The effect of elevated temperature on temperate paddy rice will be significant for dependable food supply in East Asia. Using temperature gradient field chamber (TGFC), which was designed to make the horizontal air temperature gradient by $0^{\circ}C$ to $3^{\circ}C$ higher than outside, we examined the measurement to understand the effects of extremely high temperature on paddy rice. In particular, the data of the year 2016, the worst heat wave in over 22 years, was analyzed in this study. The rice height in the relatively warmed condition was rapidly increased during early growth stage. However, the average grain weight and number of spikelet per panicle in the warmed chamber condition were gradually declined with increasing air temperature averaged for 40 days after first heading in each chamber. In particular, the grain yield was more dramatically decreased by the raising temperature because the percent ripened grain was quickly dropped as getting over the threshold temperature for pollination. Therefore, the surplus photosynthetic product by such lower grain filling rate may disturbed the decreases of the NDVI (Normalized Difference Vegetation Index) and SPAD chlorophyll values after first (normal) heading. In addition, the late-emerging head grain were appeared. However, this yield was too small to recover the normal yields decreased by extremely high temperature condition. Our result represented that the warmed condition in 2016 would be the critical limit for the stable yield of temperate paddy rice.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.1
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• pp.53-61
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• 2013

The characteristics of methane production from pig manure slurry was investigated using anaerobic digestor combined with compost filtration bed. In this study, raw pig manure slurry was digested in mesophilic rectangular digester (effective volume $250m^3$) for 25 days and anaerobic digestion wastewater was filtered through compost filtration bed, which is composed of double layer, sawdust and chaff. The characteristics of anaerobic digestion wastewater were BOD 1,800 mg/L, COD 3,500 mg/L, SS 11,800 mg/L, T-N 1,200 mg/L and T-P 350 mg/L. After the filtration process, the contents of BOD, COD, SS, T-N and T-P of the anaerobic digestion wastewater were reduced by 97%, 62%, 89%, 39% and 57%, respectively. The concentrations of N, $P_2O_5$, and $K_2O$ of the leachate were 1,024, 111 and 407 mg/L, respectively. However, there was no odor emitted from the leachate.

• Weed & Turfgrass Science
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• v.6 no.3
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• pp.272-281
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• 2017

This study was conducted to evaluate the effect of liquid fertilizer containing humic acid (LFHA) on changes of creeping bentgrass quality and growth. Treatments were designed as follows; control fertilizer (CF), HA-1 ($CF+1ml\;m^{-2}LFHA$ LFHA), HA-2 ($CF+2ml\;m^{-2}LFHA$ LFHA), and HA-3 ($CF+4ml\;m^{-2}LFHA$). As compared with CF, soil chemical properties and chlorophyll content of clipping of LFHA treatments were not significantly different. Visual quality in both of HA-2 and HA-3 treatments was higher than that of CF treatment from September to November, and clipping yield on October 27. Shoot density, root length, and the content of nitrogen, phosphorus or potassium were increased by application of LFHA. The clipping yield was positively correlated with phosphorus content, potassium content or shoot density. Similarly, LFHA level was proportionate to clipping yield of creeping bentgrass, and N, P, K contents in the leaf tissue. These results generally demonstrated that the application of LFHA improved the growth and quality of creeping bentgrass by increase of N content or P in leaf tissue.

• Weed & Turfgrass Science
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• v.4 no.4
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• pp.390-396
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• 2015

Water shortage is becoming a serious problem of turfgrass management on sand green. Many superintendents in golf course in Korea have interested in use of irrigation of recycled water for turfgrass water management. This study was conducted to investigate the effect of greywater as an irrigation source on the growth and quality of creeping bentgrass green. Turfgrass was irrigated with tap water (TW) and greywater (GW), under with or without compound fertilizer application (nonfertilizer + TW, N-TW; non-fertilizer + GW, N-GW; fertilizer + TW, F-TW; fertilizer + GW, F-GW). The chemical properties of the green sand soil were not changed by irrigation. Turf color index, chlorophyll index, root length, clipping yield and nutrient uptake of GW treatment were similar to TW treatment. The growth and quality of turfgrass were more likely related with the fertilizer application than irrigation source or quality. These results indicated that GW could be used as alternative irrigation source on the sand greens of golf courses.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.26-33
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• 1996

A nutrient solution culture experiment was conducted in the greenhouse at Suwon Campus. Kyung-Hee University from May 23 to July 11. 1995, to determine the effects of potassium application on seedling growth of Kwanganok and Hwengsungok cultivars of corn. Potassium was treated with four different levels, which are 0.248.496 and 744ppm for treatments without potassium (-k), standard potassium concentration (K), double(2k) and triple (3k) of standard potassium concentration, respectively. Plants were harvested at weekly interval for seven weeks. at which time plant height, leaf area and dry matter yield of corn seedling were measured, only chlorophyll content was taken for five weeks from three week after planting. Seedlings growth of Kwanganok and Hwengsungok cultivars was greatly retarded from planting to harvesting time in 3k treatment. The plant height, leaf area and dry matter yield of both cultivars during the whole period were decreased in order of K>2F>-K>3K, but dry matter yield of Kwanganok cultivar was decreased in order of 2K>K>-K>3K. Chlorophyll content of Kwanganok and Hwengsungok cultivars was irregularly fluctuated during growing period. but generally highest in K treatment and lowest in 3k treatment. The crop growth rates of seedlings of both cultivars were slow until the 3rd week after planting. but very fast thereafter. In general, CGR of both cultivars was higher in K and 2k treatments than -k and 3k treatments.