• Journal of Applied Biological Chemistry
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• v.57 no.1
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• pp.95-101
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• 2014

Nonpoint pollution sources from agricultural activities are a major cause of water quality impairment. A nutrient management program utilizes farm practices that maintain efficient crop production systems and control agricultural nonpoint pollution sources. The objectives of present study were to identify appropriate best management practices (BMPs) according to changes of cropping system of main upland crop for reducing AGNPs loadings and to simulate the effects of the application of the several BMPs scenarios in Saemangeum watershed. The selected BMP scenarios were: 1) to convert naked barley and hulled barley to hairy vetch or chinese milk vetch, 2) to convert red pepper to soybean crop, and 3) to combine two scenarios, converting naked barley and hulled barley to hairy vetch or chinese milk vetch + converting red pepper to soybean crop. As a result of BMPs application, the crop requirement of nitrogen and phosphorus for upland crop reduced nitrogen by 41% and phosphorus by 47% in scenario 1, whereas scenario 2 reduced nitrogen by 30% and phosphorus by 23%. Overall, scenario 3 reduced nitrogen by 72% and phosphorus by 70% in agricultural non-point pollution sources associated with chemical fertilizer and livestock manure in Saemangeum watershed.

• Journal of Practical Agriculture & Fisheries Research
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• v.3 no.1
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• pp.20-29
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• 2001

This study was carried out to find out basic data of the various cropping systems controlling the soil environment by analysing the historical literature, the changes of cropping system and the expected income of cropping system of the upland crop. The results were summerized as follows ; 1. According to the literature of 'Gumyangjoprok' and 'Sanlimgyungjae', published on 15 to 16 century in Korea, the cropping system of barley, soybean, red bean, and millet, etc. was done together both the 'kunkyong' and 'kanjong'. 2. Since 1970s the staple food grains had been self-sufficient and the setting up of the rice seedbed became faster. However, the cropping system of the rice after barley was rapidly fallen from 83.7% to 4.0% in 1990s. Furthermore, the food production and the rate of arable land utilization were also rapidly fallen. 3. The most prospective cropping system is considered the soybean after barley, and root & tuber crops considering with the soil environment. 4. The expecting income of cropping system ranged from 940,000won to l,970,000won per 10a but that of barley after soybean cropping for 610,000won, and that of barley-after mung bean cropping for 613,000won. 5. The maintenance and the preservation of agricultural environment shall become positive by practicing the Integrated Nutrients Management(INM), and the Integrated Pest Management(IPM) with control using of fertilizer and pesticide presenting the excessive loads to the soil environment.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.779-786
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• 2012

Many farmers have been seeking alternatives to chemical fertilizer for successful organic fruit production. This experiment was carried out to investigate the replaceability of chemical fertilizer by cover crop and slurry composting biofiltration (SCB) liquid manure (LM) application in pear orchard. Three treatments were contained in this experiment; cover crop only and cover crop + LM treatment, and control (chemical fertilizer application). Dry weight and mineral contents of gramineous cover crops were significantly increased in LM-combined treatments than that of leguminous species. Bulk density of soil was decreased in rye + LM and hairy vetch + LM treatments, compared with each cover crop treatment. Soil pH was lowest in fertilizer treatment and soil nitrate content became similar between treatments after rainy season. Available soil phosphate was lower in cover crop and cover crop + LM treatmemts than control, but exchangeable Mg was higher. The mineral content and net assimilation rate of leaves showed no difference between the treatments. As a result, it is suggested that the application of SCB liquid manure in pear orchard managed by cover crops is desirable to maintain the productivity by improving soil physical properties and potential nutrient recovery.

• Journal of Sericultural and Entomological Science
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• v.35 no.2
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• pp.145-148
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• 1993

생산성 저해 요인의 제거는 바로 생산성 향상으로 연결된다. 뽕밭의 생산성을 저해하는 요인은 여러가지지만 그 중에서 토양의 이화학적 불량과 농약 공해가 비중이 가장 크다고 볼 수 있다. 우리나라 뽕밭은 입지가 경사지에 많으므로 토심이 얕은데 비해, 뽕나무는 영년성 심근성 작물이므로 식재후 근권의 물리성에 따라 생산성이 좌우되는 비중이 매우 크다. 그러나 식재후 토양 물리성 개량은 화학성 개량보다도 어려우므로 그 결과 생산성이 낮은 상태를 벗어날 수 없다. 따라서 정기적인 심경이나 심토 파쇄를 통한 물리성 개량이 요망된다. 계속적인 금비위주의 비배관리에 의해 강산성 반응을 보이는 토양이 대부분이므로 석회에 의한 산성개량이 필요하다. 질소질의 과다시비는 수량을 감소시킬 뿐만 아니라, 엽질을 악화시키고 질산태 질소가 지하로 흘러 들어가 지하수의 오염을 일으켜 청색증과 암을 일으키는 원인이 될 수 있다. 심각한 정도로 축적된 인산과 칼리도 수량을 떨어뜨리고 환경을 해치는 원인이 되므로, 축적 양분의 재활용에 대한 연구가 계속되어져야 한다. 특히 사용의 편리성 때문에 고농도의 복합비료 위주의 비배관리가 반복되고 있는 실정이므로 토양검정을 받아서 단비를 이용하여 적정한 시비를 해야 할 것이다. 이러한 방법은 생산성의 향상, 영농비의 절감, 공해의 유발을 억제하는 여러가지 효과가 있다. 농약과 산업공해로부터 양잠의 보호를 위해서는 안전지대에 잠업의 단지화, 인근 농과와의 대화를 통해서 양잠에 안전한 농약을 사용토록 하는 한편, 연구분야에서는 심도 있는 연구를 통해 양잠농가를 보호할 수 있는 대책의 수립이 요망되고 있다. 종합해서 말하자면 연구기관의 심도있는 연구가 더욱 활발히 이루워져야 할 것이며, 농민은 개발된 새기술에 보다 깊은 관심을 갖고 활용하는 한편, 필요로 하는 기술을 연구기관에 개발을 요청할 정도의 적극적인 자세가 요구된다. 또한 연구기관의 농민의 중간 교량역할을 하는 지도부문에서도 보다 적극적인 활동이 요청된다.

• Proceedings of the Mineralogical Society of Korea Conference
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• 1996.10a
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• pp.90-103
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• 1996

식물 양분으로서 유황의 중요성에 관심이 증가되고 있으며 더욱이 대기에서 유래된 유황함량이 감소되고 집약적인 농업으로 유황의 수요가 늘어나고 있다. 호주에서 유황 부족 현상이 1915에 확인된 이래 이 문제를 해결하기 위한 장기적이고 지속적인 연구가 수행되었다. 1980년까지 과석 사용으로 유황의 결핍상황은 나타나지 않았으나 작물 재배가 집약화되고 과석이 고농도비료로 대체되어 사용되면서 유황부족 현상이 증가되었다. 호주의 다우 지역에서 수행된 인광석 시험포장 30군데 중$43\%$가 2년 차에서 효과가 있었다. 토양 유황 검정사업을 통해 유황 분포상황을 파악하게 되었고 시기에 맞는 연구를 통하여 유황 비료 시용으로 유황 결핍을 극복할수 있는 비료정책 발전에 기여하게 되었다. 인도네시아에서는 유황 부족 현상은 과석과 유기질 비료 시용에서 중과석과 요소로 대체되면서 진전되었다. 쌀 생산을 위한 국가 계획에 유안을 질소로서 $25\%$ 포함시킨 효과적인 지도 활동으로 좋은 결과를 얻고 있다. 시비관리로 유황 부족 지역에 유황을 시용하는 노력을 지속하고 있다. 쌀 생산을 위한 유황비료 종류, 시용시기 및 위치 등에 관한 연구가 실용적으로 수행되고 있다. 인도네시아에서의 효과적인 종합 양분으로서의 유황 문제 해결은 연구, 지도, 행정 및 산업계의 상호 밀접한 관계를 요구하고 있다. 중국에서는 유황 부족 토양은 대기로의 유황 방출이 감소되고 고농도 비료, 저유황 비료의 시용으로 급격하게 증가되고 있다. 대부분의 중국 토양은 유황 흡수능이 낮아 생산성은 시용 유황 함량에 따라 결정된다. 유황 결핍과 양분으로서의 수지균형 관계를 이해 하므로서 농업에서의 유황 관리 체계 수립이 무엇보다 중요하다.X>$\mu\textrm{g}$ L$^{-1}$에서는 5.4%로서 가장 낮은 성장을 보였다. 성장률의 전체적인 양상은 노출농도가 증가할수록 성장이 떨어지는 결과를 보였으며, 사료효율과 마찬가지로 노출농도 80 $\mu\textrm{g}$ L$^{-1}$ 이상에서 유의한 감소를 나타냈다.circ}C$에서 각각 3.95-28.9개, 2.9-28.95개 및 1.7-13.6개로 제공된 먹이간에 차이가 현저하였다. 따라서 먹이간 성충 포식량의 현저한 차이는 기주선호성에 따른 것으로 생각된다.군에서 높았으며, elongation index(20:4$\omega$6⇒22:4$\omega$6)는 old군에서 낮았다. 대부분의 elongation과 desaturation 단계는 연령에 따라 유의한 차이를 보이지 못하였으나, $\omega$3계 지방산의 전체적 elongation-desaturation 단계를 나타내는 products-fatty acid($\omega$3)/a-LNA($\omega$3) 비율이 old군에서 young군보다 유의하게 높아, 연령에 따른 PUFA 대사의 변화가 관찰되었다. 이 상에서와 같이, 콩 단백질의 섭취로 흰쥐 혈장 인지질의 ∑MUFA조성은 낮고 ∑SFA 조성은 높아 다른 지질 강화성 분의 섭취와 유사한 결과를 나타내었다. 혈중 콜레스테롤 수준이 높은 old군에서 체내 막조직의 유동성을 유지하기 위해 PUFA의 합성 특히 $\omega$3계 지방산의 elongation-desaturation이 증가하여 총 PUFA 조성이

• Korean Journal of Organic Agriculture
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• v.14 no.1
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• pp.55-67
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• 2006

A survey of 31 organic farmers were conducted to investigate the actual conditions of organic matter application. The amounts of organic matter application in the fields were higher in order of fruit, vegetable and rice farm. The average was 50 ton/ha in vegetable farms. In the green vegetable farms saw dust and animal manure were mainly utilized to make compost. Rice straw, wood chip, and forest bushes were also used for composting. In the fruit vegetable farms materials relatively lower in nitrogen content such as rice straw and cattle manure were used in vegetative period and materials higher in nitrogen content such as oil cake and wild grass were used in reproductive phase. Nutrient balance investigated in the farm in Icheon region who produce lettuce, angelica, and kale continuously in one cropping year indicated surplus in three major nutrients. Nitrogen and phosphorous were in excess by 29 and 10 kg respectively in the organic rice farm in yang-pyoung region. While soil chemical properties in the organic farms are within the adequate range in open field, it is much higher than the limits in the greenhouse soils. Overall application of organic matter is in an oversupply state. This results suggested that the organic matter management should be based on the soil conditions for sustainable cultivation. Chemical composition of organic matters and soil test reports should be considered prior to the application of organic matter.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.235-240
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• 2012

This study was conducted to find out the optimum cropping system for the stable production of forage crops in the newly reclaimed land located at Gwanghwal region of Saemangum reclaimed land in which the soil is sandy loam (Munpo series). There were two treatments of nitrogen fertilization 20% increment based on the standard fertilization of 150, $200kg\;ha^{-1}$. Whole crop barley as the winter crop sowed on 27 October. After the whole crop barley was harvested at the end of May. Corn and sorghum${\times}$sudangrass as the summer crop sowed at the early of June successively on the same field. Emergence rate the whole crop barley was high while the summer crops were low. Soil salinity was increased during cultivation of summer crops. However, corn and sorghum${\times}$sudangrass were not damaged by salt. Increase of nitrogen fertilization made the growth of cultivation crops good, stem and leaf tended to have a lot of the mineral nutrients at heading stage and silking stage. After experiment, among soil chemical properties pH, content of exchangeable sodium were decreased and content of organic matter, available phosphate were increased. Dry matter yield were showed whole crop barley $13,170kg\;ha^{-1}$ and sorghum${\times}$sudangrass $19,440kg\;ha^{-1}$ by increment of nitrogen fertilization. Therefore, to improve the product and nutrient balance of reclaimed saline land comprehensive soil management should be considered.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.680-686
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• 2018

Nitrogen fertilizers, hairy vetch, and slow-release complex fertilizers were applied to the soil during the cultivation of crops. The impact of these factors on $N_2O$ emission was quantitatively assessed and the GHGs reduction effect comprehensively evaluated. Among the three factors, the significant factors affecting $N_2O$ emission were mineral nitrogen>soil moisture>temperature. Yield and fertilizer utilization efficiency were highest in the slow-release complex fertilizer treatment. There was no significant difference in $N_2O$ emissions between the slow-release complex fertilizer treatments and the NPK+hairy vetch treatments. Comprehensive results showed that slow-release complex fertilizers treatment has high yield and fertilizer utilization efficiency but low $N_2O$ emission.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.717-721
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• 2011

In case of plastic film greenhouses cultivating fresh vegetables on paddy soil, soil characteristics must be considered as more important factor than any other factors. Generally after the four years of cultivation, soils tend to increase electrical conductivity value, nutrient unbalance and soil pests. As a result, degradation of agricultural products occurred, therefore it is necessary to improve soil conditions. In this study, yield and economic cost of cucumber were analyzed. The best soil conditions for cucumber cultivation were alluvial or valley in soil topology, moderately or poorly drainage in soil drainage classes, coarse loamy soil in texture. In addition, rich-sunlight and-deep groundwater would be proper for the cucumber cultivation. Good environmental managements of plastic film greenhouse were as follows. The temperature needed to be adjusted three times. The optimal daytime temperature could be $22{\sim}28^{\circ}C$, the one from 12 until night could be $14{\sim}15^{\circ}C$, and the temperature from 24 to sunrise could be $10{\sim}12^{\circ}C$. During plant growth period, soil moisture content was as low as 10~15%, and it needed to be maintained as 15~20% during reproductive growth period. To control pests, catch crop cultivation and solar treatment were carried out, after those EC was reduced and the root-knot nematode was controled too. Cucumber yield from the plot with improved soil managements increased to $158.4Mg\;ha^{-1}$, but plot with successive cropping injury yielded $140.3Mg\;ha^{-1}$. The income from the plot with improved soil managements was 215,676 thousand won $ha^{-1}$, the plot with successive cropping injury was 131,649 thousand won $ha^{-1}$. Income rate of each plot was 51.8% and 38.4%, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.2
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• pp.6-14
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• 1980

One of the physiological disease, sudden wiliting of Yushin variety suggested that low sunlight, excessive nitrogen application, and highly reduced soil condions either singly or combined, might be possible causes of the disorder. Some visual symptom of sudden wilting are discoloration of leaves, development of nodal roots above the soil surface, total root rot, and lodging. Those observations led to the hypothesis that suffocation of root tissues was a direct cause of the wilting. The oxygen transport characteristics of Yushin, IR262 and Tongil were examined by two methods. First, Soil-cultured plants of the three varieties were subjected to paraffin treatment to decrease the oxygen supply from the air to root tissues through the soil-water system, liquid paraffin was applied to the water surface in the pots at panicle formation stage. In this experiment, sudden wilting was observed of Yushin and IR262 at about a week after the treatment, but Tongil remained green and healthy. Wilting-resistant variety Tongil had higher oxygen release, whereas the susceptible Yushin and IR262 had lower oxygen release. Second, the number and size of the air spaces in each internode were investigated in the 5th internode from the top, all three varieties have a similar number of air spaces, although the air spaces of Thongil were larger. In the 4th internode, Tongil had plenty air spaces, Yushin and one of the Yushin's parents IR262 had scanty or none. The observations indicated that the ability of Yushin and IR262 for oxygen transport is very limited compared with that of Tongil. The limited oxygen supply due to poor development of air space in internode of rice plants may cause suffocation of root tissues, weaken metabolic activity of the tissues, and induce root rot, subsequently inducing sudden wilting and lodging under unfavorable weather, soil and cultural conditions.