• 한국환경과학회지
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• 제30권12호
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• pp.1015-1025
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• 2021

Our research work aimed to evaluate cover crop effects of winter rye on soil characteristics, soil conservation, and yield productivities on potato fields with 15% slope during a fallowed period. There were two controls of bared field without any cultivation and conventional potato cultivation without winter rye. Potato cultivation increased soil pH, organic matter, available phosphate, and exchangeable cation regardless of cover crop cultivation. Sub-soil, particularly, all components of soil chemical properties showed higher value in winter rye cultivation than conventional cultivation. Higher soil density was observed on cover crop cultivation than conventional cultivation resulting from root residues of the cover crop both topsoil and subsoil. Cover crop residues positively affected plant growth and reduced the amount of soil erosion by holding the soil. Although severe soil erosion was seen in conventional cultivation, winter rye cultivation declined soil erosion by 47% during the fallow period on potato slope fields. Distinct soil bacterial communities were detected among treatments and some OTU(Operational Taxonomic Unit)s showed significantly higher abundance in winter rye treatment. Total yield and commercial rate demonstrated no significant differences while higher tuber phosphate, K⁺, and Mg²⁺ contents were observed in winter rye cultivation.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.346-346
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• 2017

In Northern Laos, maize is cultivated in continuous cropping without fertilizer, fallowing nor any other soil conservation practice. It is expected that this inadequate management in maize cultivation will degrade soil and decrease yield. However, there is limited information about the change of soil condition and yield under continuous maize cultivation. We tried to evaluate the change of soil condition and yield under continuous maize cultivation in Northern Laos. Our study was conducted in farmer's flat and slope fields in Sainyabuli province where maize cultivation had been introduced earlier than the other provinces of Northern Laos. Our study was conducted in 21 fields in 2014, and in 19 fields in 2015. We analyzed grain yield and soil characteristic (total carbon (TC), total nitrogen (TN), available phosphorus (Av-P), exchangeable cation, pH, soil texture) at 3 places in each field. The 3 places were set at different elevation level (lower position, middle position, upper position) in slope fields. Further, the period of continuous maize cultivation and crop management practice were investigated. Then, by evaluating the relation between the period of continuous maize cultivation and yield and the soil characteristics, the effect of maize cultivation was estimated. Crop management practices were similar among the investigated fields. Maize was cultivated in rain season. Grain seed and cob were harvested on September or October, but shoot was left on the fields. No crop was cultivated during dry season. Fertilization and fallowing has never been conducted under continuous maize cultivation. On the other hand, the period of maize cultivation was different among the fields, and ranged from 2 years to 30 years. In the slope fields, as the period of continuous maize cultivation was longer, the contents of TC and TN were lower at all 3 positions, Av-P content was lower at the upper position, exchangeable potassium (Ex-K) content was lower at the middle and the upper positions. The other soil characteristics weren't related with the period of maize cultivation in the slope fields. In contrast, soil characteristics weren't related with the period of maize cultivation in the flat fields. Yield was lower as the period of maize cultivation was longer at the upper position of the slope fields. At middle position of slope fields, yield tended to be low with increase of the period of maize cultivation. In contrast, yield wasn't related with the period of continuous maize cultivation in flat fields. From the results about crop management, it was presumed that the period of maize cultivation was one of the main factors causing the difference of yield and soil characteristics among the fields. Therefore, from the result of yield and soil condition, it was considered that the continuous maize cultivation decreased soil productivity in the slope fields with decline of TC, TN, Av-P, Ex-K and yield at upper position of slope fields, and decline of TC and TN in the other positions in Sainyabuli province.

• 한국토양비료학회지
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• 제49권4호
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• pp.335-340
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• 2016

Soil organic carbon plays an important role on soil physico-chemical properties and crop yields in paddy soil. However, there is little information on the soil organic carbon under different forage cultivation during winter season in rice paddy. In this study, we investigated the soil organic carbon and physico-chemical properties in 87 fields of paddy soil cultivated with Barley, rye, and Italian ryegrass (IRG) as animal feedstock during winter season. Organic carbon was 12.9, 14.3, and $16.9g\;C\;kg^{-1}$ in soil with barley, rye, and IRG cultivation, respectively. Among rice-forage cultivation systems, the rice+IRG cropping system was 19.5% higher than in the mono-rice cultivation. Bulk density ranged from 1.17 to $1.28g\;cm^{-3}$ irrespective of cropping systems, and had strongly negative correlation with the soil organic carbon in the rice+IRG cropping system. Carbon storage in rice+IRG cropping systems was average $29.6Mg\;ha^{-1}$ at 15 cm of soil depth, which was 20.4 and 10.3% higher than those of barley and rye cultivation. Increasing carbon storage in paddy soil contributed to the fertility for following rice cultivation. This results indicated that IRG cultivation during winter season could be an alternative and promising way to enhance soil organic carbon content and fertility of paddy soil.

• 한국약용작물학회지
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• 제28권3호
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• pp.209-220
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• 2020

Background: This study investigated the effects of soil properties on the soil fungal community in first and continuous cultivation areas of Cnidium officinale Makino. Methods and Results: The soil fungal community was analyzed for relative abundance and principal coordinate analysis (PCoA) was conducted using Illumina MiSeq sequencing. The correlation between the soil chemical properties and the soil fungal community was assessed with distance-based linear models (DISTLM). The soil fungal community showed distinct clusters consisting in the continuous cultivation area of C. officinale Makino. PCoA and DISTLM indicated that soil pH, calcium, and available P₂O₅ significantly affected the soil fungal community in the cultivation area of C. officinale Makino. In addition, considering 5 different pathogenic fungi the relative abundance of Fusarium in the continuous cultivation area was significantly higher compared to that in the first cultivation area of C. officinale Makino. Conclusions: This study is important because it has determinined the effects of soil properties on the soil fungal community in both first and continuous cultivation areas of C. officinale Makino. Moreover, these results will be helpful to investigate the cause of continuous cropping obstacle in C. officinale Makino by examining the changes of soil fungal community.

• 한국환경과학회지
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• 제30권5호
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• pp.379-389
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• 2021

Soil microorganism activity in an agricultural field is affected by various factors including climate conditions, soil chemical properties, and crop cultivation. In this study, we elucidate the correlation between microorganism activity and agricultural environment factors using the dehydrogenase activity (DHA) value, which is one of the indicators of soil microbial activity. As a result, the various factors noted above were related to the DHA value. Annual rainfall, soil Mg2+, bacterial and fungal diversities, types of crops, developmental stages, seasons, and cultivation status were highly correlated with the DHA value. Furthermore, next-generation sequencing (NGS) analysis was used to identify that the type of crop affected soil microbial compositions of both bacteria and fungi. Soil used for soybean cultivation showed the highest relative abundance for Verrucomicrobia, Planctomycetes, and Acidobacteria but Actinobacteria and Firmicutes had the lowest relative abundance. In the case of soil used for potato cultivation, Actinobacteria had the highest relative abundance but Proteobacteria had the lowest relative abundance. Armatimonadetes showed the highest relative abundance in soil used for cabbage cultivation. Among the fungal communities, Mortierellomycota had the highest relative abundance for soybean cultivation but the lowest relative abundance for cabbage cultivation; further, Rozellomycota, Chytridiomycota, and Cercozoa had the highest relative abundance for cabbage cultivation. Basidiomycota had the highest relative abundance for potato cultivation but the lowest relative abundance for soybean cultivation.

• 한국환경과학회지
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• 제30권2호
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• pp.145-152
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• 2021

Soil conservation management is necessary for sustainable agriculture, in highland areas, and cover crops are one of the best soil conservation methods for slopes. In this study, we evaluated the effects of alfalfa cultivation on maize production, as well as soil conservation and quality. There was an outstanding soil conservation effect with alfalfa cultivation in the fallow and maize growing seasons. In particular, alfalfa cultivation reduced soil loss by up to 98% compared with bare field. It also increased the activities of soil microorganisms and the supply of organic matter. Maize production with alfalfa cultivation showed no significant differences in yield. In conclusion, alfalfa is an advantageous perennial cover crop in highland agricultural slope areas, which can have positive effects on soil quality and conservation, as well as maize production.

• 한국토양비료학회지
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• 제50권6호
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• pp.634-643
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• 2017

No-tillage is an effective practice to save labor input and reduce methane emission from the paddy. Effects of tillage and cultivation methods on carbon accumulation and soil properties were investigated in the treatments of tillage-transplanting (T-T), tillage-wet hill seeding (T-WS), minimum tillage-dry seeding (MT-S) and no-tillage dry seeding (NT-S) of rice. Soil carbon was higher in NT-S and MT-S, compared to T-T and T-WS. In NT-S and MT-S, soil carbon contents were the highest in the top soil (5 cm depth) and decreased with soil depth. In T-T and T-WS, however soil carbon contents showed no significant difference up to soil depth of 15 cm from the top. Carbon content was the highest in the soil particle size under $106{\mu}m$ and decreased as the soil particle size increased. Contents of water-stable aggregates in NT-S and MT-S were higher than those of T-T and T-WS. In NT-S and MT-S, contents of water-stable aggregates were the highest in the top soil and significantly decreased with soil depth while no significant difference up to the soil depth of 15 cm in T-T and T-WS. Available $SiO_2$ contents in the top soil were the highest in NT-S and MT-S while the lowest in T-T and T-WS. It is concluded that minimum or no disturbance of soil in rice cultivation can increase carbon accumulation in the soil, especially in the top layer, and subsequently contribute to the formation of the water-stable soil aggregates.

• 한국토양비료학회지
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• 제21권1호
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• pp.49-54
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• 1988

고추의 연작장해(連作障害) 요인(要因)을 분석(分析)하여 연작지토양개량(連作地土壤改良)을 위(爲)한 기초자료(基礎資料)를 얻고자 1985~1986년(年) 2개년(個年) 동안 전북(全北) 임실군(任實郡) 관촌(館村)의 고추 주산단지(主産團地)에서 시험(試驗)을 수행(遂行)하였던바 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 조사지역(調査地域)의 연작면적비율(連作面積比率)은 2년연작(年連作)이 12.7%였으며 3년연작(年連作)이 6.8%, 4년이상연작(年以上連作)은 48.9% 였다. 2. 연작지(連作地)의 토양이화학성(土壤理化學性) 특성(特性)은 토양경도(土壤硬度)가 높고 토양삼상중(土壤三相中) 기상(氣相)의 비(比)가 낮았으며 유효인산(有效燐酸)은 508 ppm, 치환성가리(置換性加里) 0.86me/100g로 적정치(適正値)보다 월등(越等)히 높았다. 3. 토양미생물(土壤微生物)의 균류(菌類)에 대(對)한 세균수(細菌數)(B/F비(比))와 방선균수(放線菌數)(A/F비(比))는 연작연한(連作年限)이 많을 수록 낮아지는 경향(傾向)이었다. 4. 토양선충밀도(土壤線蟲密度)는 1년재배지(年栽培地) 359, 2년연작지(年連作地) 391, 3년연작지(年連作地) 495, 4년이상연작지(年以上連作地)가 524마리/100g이였으며 경사(傾斜)가 심(甚)하고 배수(排水)가 양호(良好)할수록 낮았다. 5. 역병발생(疫病發生)은 4년이상연작지(年以上連作地)의 이병주율(罹病株率)이 14.3%로 1년재배지(年栽培地)의 0.7%에 비(比)해 월등(越等)히 높았으며 경사(傾斜)가 완만할수록 탄저병(炭疽病)은 감소(減少)되고 역병(疫病)은 증가(增加)되는 경향(傾向)이였다.

• 한국토양비료학회지
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• 제41권5호
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• pp.279-284
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• 2008

화산회토 감귤원에서 제초제를 사용하는 청경재배, 자연초종을 이용하는 자연초생재배, 켄터키블루그라스를 이용하는 인위초생재배를 4년간 동일한 방법으로 토양 및 시비관리를 하면서 토양의 물리성과 미생물체량, 토양인산효소 활성을 분석하였다. 자연초생재배가 청경재배보다 입단계수(>0.5 mm)는 26.7% 높았고 토양경도는 11.8 mm 낮았다. 토양의 용적밀도와 공극율은 차이가 없었다. 초생재배가 청경재배보다 인산효소 활성이 높았으며 토양 미생물체량은 인위초생재배가 $525.4mg\;kg^{-1}$로 청경재배보다 2배 이상 높았다. 결론적으로 초생재배는 입단형성이 잘되고 토양 경도가 개선되는 효과가 있었으며 토양 미생물활성이 높았다. 비화산회토 감귤농가 중 5년 이상 된 제초제를 이용하는 관행재배, 자연 초생재배 저농약, 유기농 인증 재배 감귤원 5개를 선정하여 감귤나무의 개화기인 5월에 토양을 채취 후 인지질 지방산과 토양인산효소 활성, 미생물체량을 분석하였다. 인지질지방산함량은 유기재배 감귤원이 $112.2n\;mol\;g^{-1}$로 관행재배보다 2배 이상 많았다. 인지질 지방산의 미생물지표에 따른 유기재배토양의 그램 음성세균은 15.1%, 방선균은 6.6%로 관행재배토양 보다 높았다. 유기재배 감귤원이 관행재배보다 토양 미생물체량은1.5배 정도 많았고 토양인산효소 활성은 17.6% 높았다.

• 한국농공학회논문집
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• 제56권2호
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• pp.37-46
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• 2014

Water for crop growth were supplied by irrigation in protected cultivation and these are accumulated in the soil and utilized for crop evapotranspiration. The study for analyzing soil moisture characteristics is necessary for adequate irrigation water and soil water management in protected cultivation. Soil moisture content, irrigation water quantity and meteorological data were monitored to analyze soil moisture increment and extraction characteristics in terms of soil layers and cucumber crop growth stages. In first cropping period, the total amount of irrigation water was 5.07 mm/day, soil moisture increment was 4.82 mm/day and soil moisture extraction was 5.56 mm/day. In second cropping period, the total amount of irrigation water was 4.82 mm/day, soil moisture increment was 4.65 mm/day and soil moisture extraction was 4.73 mm/day. Soil moisture extraction rate from 0 to 75 cm is 90.3 % in first cropping period and 79.1 % in second cropping period. The majority irrigation water were consumed in root zone, however, about 15 % of soil moisture were losses by infiltration in lower soil layer. Soil moisture extraction and extraction pattern of cucumber crop calculated in this study can be utilized as a basic data for irrigation water management in protected cultivation.