장기간 호밀을 풋거름작물로 시용한 유기농 토양의 생물학적 특징

백계령,이계준,김태영,지삼녀,김창석,이형복,이은경,송재경 한국유기농업학회 2018 韓國有機農業學會誌 Vol.26 No.3

In this study, microorganism community characteristics of organic managed soil which applied rye (Secale cereal L.) as green manure for 25 years, were determined. The chemical properties of organic soil showed high level of organic matter and available P2O5, while the level of exchangeable cation was low. The analysis of dehydrogenase activity and carbon source utilization indicated that the values in on organic soil were significantly higher than those of the control. It suggested that the microorganism community of organic soil had high microorganism activity, compared to the control. In addition, when the 16S rRNA genetargeted NGS (Next generation sequencing) analysis was conducted to estimate the class of bacterial community, the class level of bacterial taxon composition on organic soil showed higher portion of Sphingobacteriia, Acidobacteriia, Gammaproteobacteria, Solibacteres and Planctomycetia. By base on the results of various reports in which organic managed soil had high portion of Acidobacteriia and Planctomycetia, the characteristic of taxon composition in organic soil, which showed the high percentages of Ktedonobacteria, Sphingobacteriia, Acidobacteriia and Gammaproteobacteria, was resulted from the application of rye as a green manure for the long term. However, further researches were needed because the crop effect was not considered in this study.

고랭지 여름배추(Brassica rapa subsp. pekinensis)재배에서 8년간 콩(Glycine max)과의 돌려짓기 재배가 토양 환경에 미치는 영향

백계령,이정태,김양민 한국환경과학회 2024 한국환경과학회지 Vol.33 No.1

In this study, we evaluated productivity, soil physiochemical properties, and soil microbial characteristics in Kimchi cabbage( Brassica rapa subsp. pekinensis) cultivation within a highland environment during summer. Specifically, we examined the effect of different cropping systems, namely monoculture and rotation with soybean, over an 8-year cropping period. The results of our investigation revealed that significant differences were absent in terms of yield and soil physiochemical properties between the two cropping systems. However, microbial characteristics exhibited distinctive patterns. Bacterial diversity was significantly higher in the rotation system that in the monoculture, whereas fungal diversity demonstrated a preference for rotation although the result was not significant. Our findings identified the presence of Bradyrhizobium stylosanthis, a nitrogen-fixation symbiont, as an indicator ASV (amplicon sequence variant) in the rotation system, where it displayed significantly higher abundances. These observations suggest a potential positive effect of the rotation system on nitrogen fixation. Notably, throughout the cultivation period, both cropping systems did not exhibit critical disease incidences. However, Fusarium oxysporum, a well-known pathogen responsible for inducing fusarium wilt disease in Kimchi cabbage, was detected with significantly higher abundance in the monoculture system. This finding raises concerns about the potential risk associated with Kimchi cabbage cultivation in a long-term monoculture system.

콩 재배가 토양 미생물 군집 활성도에 미치는 영향

백계령,이계준,김태영 한국환경농학회 2019 한국환경농학회지 Vol.38 No.2

BACKGROUND: For sustainable agriculture, there are various agricultural practices including low input. Over the last few decades high input of chemical fertilizer and compounds results in environmental pollution and deterioration of soil fertility. Soybean (Glycine max L.) is well known eco-friendly crop due to their symbionts. Soybean has a relationship with nitrogen fixation bacteria called rhizobia. In this research work, we investigated effects of soybean cultivation on soil microorganism activities. METHODS AND RESULTS: Experiments were conducted in pots and potato cultivation was used as reference. Soil chemical properties were analyzed considering soil nutrient over cropping period. For the soil microbial community analysis, dehydrogenase activity analysis (DHA) analyzed along with denaturing gradient gel electrophoresis. The results showed that higher soil organic matter in the soybean cultivation soil than in the potato cultivation soil. Available P2O5 concentration increased gradually in both pots but showed higher value in the potato cultivation soil. DHA value implying microbial activities showed higher value in the soybean cultivation soil over all cropping period. CONCLUSION: The cause of high microbial activity in the soybean cultivation soil was considered to the effects of some specific microorganisms related to soybean cultivation. Therefore, the availability of soybean cultivation for sustainable agriculture should be encouraged in terms of microorganism community activity in soil.

고랭지 농업에서 알팔파 재배가 토양유실 및 옥수수 생산에 미치는 영향

백계령,이정태,Bak, Gyeryeong,Lee, Jeong-Tae 한국환경과학회 2021 한국환경과학회지 Vol.30 No.2

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.

경사밭 감자(Solanum tuberosum L.) 재배 시 휴한기 호밀(Secale cereal L.) 재배에 따른 토양 특성 및 토양 보전 효과

백계령,이정태 한국환경과학회 2021 한국환경과학회지 Vol.30 No.12

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.

톱밥 및 요소의 투입이 감자 더뎅이병 병원균(Streptomyces scabiei) 및 감자 더뎅이병 이병도 지수에 미치는 영향

백계령,이정태,지삼녀 한국환경과학회 2023 한국환경과학회지 Vol.32 No.11

Potato common scab disease is caused by pathogens belonging to Streptomyces spp. and results in a serious yield loss worldwide. Despite decades of research aimed at disease management, a definitive control method remains undiscovered. This study aims to explore the correlation between the C/N ratio and urea application with potato common scab pathogen dynamics and disease severity. We applied sawdust with a high C/N ratio and urea into the soil prior to potato cropping, both in pot and field experiments. Disease severity assessments and quantification of the TxtB gene were conducted at the harvest stage. Furthermore, culture experiments were performed to assess the direct impact of urea on the pathogen. Our findings revealed that higher disease severity was correlated with a high C/N ratio application and pathogenic gene quantity. Urea exhibited a direct influence on S. scabiei activity, reducing the disease severity in pot experiments. However, the effects of urea application on disease suppression in the conductive field were inconclusive. Although the results of urea application experiments displayed inconsistencies between pot and field trials, urea worked as the control to suppress S. scabiei activity. Further investigations are needed under various field conditions to confirm these findings.

농경지에서 재배작물이 토양미생물활성 및 군집구성에 미치는 영향

백계령,이정태,지삼녀 한국환경과학회 2021 한국환경과학회지 Vol.30 No.5

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.

토양유실 자동화 수집기를 통한 토양유실량 추정

백계령,오동식,이계준,김태영,이정태 경상대학교 농업생명과학연구원 2020 농업생명과학연구 Vol.54 No.1

물 유거(Run-off)에 따른 토양유실량을 자동정량하고자 ISCO 6712 수질환경 종합측정장치를 이용하여 토양유실량 추정장치를 고안하였고, 이 장치를 통해 실시간으로 유실되는 토양량을 추정할 수 있었다. 토양유실량 추정장치는 ISCO 6712 장치에 수위계(ISCO 730), 우량계(ISCO 674) 그리고 흙탕물을 받는 저수조 내에 층위 별로 흙탕물을 자동으로 채취할 수 있는 시설을 추가하였다. 1 × 5 m2 크기, 경사 15 %의 라이시미터(lysimeter) 내 석비레(Saprolite) 토양에 옥수수를 심어 실험한 결과 2017년 1회 강우량 161.3 ㎜의 강우사상에서는 실측 토양유실량의 85.1%, 82.6 ㎜ 강우사상에서는 101.7 %의 토양량을 추정하였다. The research of soil conservation, especially in agricultural slope field, was not an easy work because of the difficulty of the precise measurement of soil losses. This research aims at the real-time quantification of soil losses measurement. The automatic measurement tool of soil losses was plotted with water environment research equipment ISCO 6712 model attachable to ISCO 674 rain gauge and ISCO 730 bubbler flow module. Besides, to detect the suspended concentration of run-off water the sampling bottle was connected to each water level horizon in reservoir tank at 10 cm interval. Using our planned installations, soil losses content was detectable over time and the estimated soil loss quantity approached to the measured loss amount at the confident range of 85.1% and 101.7% in a storm of 161.3 ㎜ and 82.6 ㎜ rain of 2017 year.

건조스트레스가 감자 식물체 무기성분 및 생육에 미치는 영향

백계령,이계준,조지홍,Bak, Gyeryeong,Lee, Gyejun,Cho, Jihong 한국작물학회 2017 한국작물학회지 Vol.62 No.3

Yield of potato is largely influenced by drought stress. This study was conducted in Gangneung and Cheongju during the spring cropping of potato. Potatoes in the Gangneung area were affected by drought but there was no damage due to drought in Cheongju. During the early-growth stage, the contents of inorganic components like available phosphate and growth characteristics of the potato leaf in Cheongju were significantly higher than those in Gangneung but there was no difference after the flowering stage. It was considered that the potato plants cultivated in Cheongju could vigorously grow than that of Gangneung under drought stress. In addition, the content of calcium (Ca), which is a secondary messenger related to aging, was found to be higher in potato plants grown in Cheongju than in Gangneung and accumulated more quickly in potato plants of Cheongju. Because magnesium (Mg) was also found to be higher in potato plants from Gangneung by a wide margin, this phenomenon was thought be related with drought stress. The amounts of all inorganic components absorbed from soil were higher in Cheongju than in Gangneung, showing a relatively higher plant biomass in Cheongju. Correlations of development indexes related to leaf showed less or no relation in Gangneung. According to yield characteristics of the harvest stage, although yield was greatly reduced under drought stress condition, the rate of commercial yield was not significantly affected under the drought stress condition. Consequently, it was considered that these responses to drought stress could be utilized to stabilize potato production under the stressful conditions associated with abnormal climate.

Crop rotation affects biological properties of rhizosphere soil and productivity of Kimchi cabbage (Brassica rapa ssp. pekinensis) compared to monoculture

백계령,이계준,이정태,지삼녀 한국원예학회 2022 Horticulture, Environment, and Biotechnology Vol.63 No.5

Crop rotation is a management practice that effectively improves soil quality and crop yield. Damage caused by monoculture has been reported for kimchi cabbage (Brassica rapa subsp. pekinensis), one of the major crops in South Korea. In this study, the influences of crop management on soil characteristics, especially biological properties and kimchi cabbage productiv- ity, were investigated using a pot experiment. Specifically, the effects of two crop management schemes were compared: monoculture and rotation with soybean and potato. Soil biological characteristics were studied using both entire and specific community analysis. Increased productivity was recorded under the rotation management scheme, as well as higher mineral contents during the leaf growth stage. In addition, higher microbial activity was observed under crop rotation, although specific groups showed higher activity under monoculture management. PERMANOVA analysis results showed significant association between microorganism community and growth stage or crop management. Higher bacterial and fungal diversities were also observed under crop rotation management. Furthermore, some microbial groups showing a higher composition under crop rotation were associated with soybean cultivation.