The system of rice intensification (SRI) has been proposed as a way of transitioning towards more sustainable rice farming. In rainfed rice farming, however, various environmental constraints often make SRI practices challenging to adopt. We conducted an on-farm experiment in 30 rainfed lowland fields to examine the technical efficacy of SRI in southern Cambodia during the wet seasons of over three years of 2012, 2013, and 2015. Across the three years, the SRI practices produced significantly greater plant biomass and grain yield than non-SRI. We ascribed the yield increase to the increased number of grains per land area as the increased number of spikelets per panicle rather than the number of panicles per land area. With no significant difference in seedling age between the SRI and the non-SRI, we attributed the more substantial number of grains per panicle to the reduced planting density, increased manure application, and reduced amount of inorganic fertilizers in SRI fields. Our results suggest that the advantage of the SRI lies in the efficient use of internally available soil nutrients, whose mechanisms need quantitative understanding through future studies.

The cocoa sub-sector is an important pillar of Ghana’s economic stability and growth prospects; the sub-sector contributes to fiscal stability, infrastructure, and employment. In recent times, diversification has become a common observable feature in the industry. This study uses the conditional mixed process approach to examine the interaction between the diversification status and profitability of cocoa farming simultaneously in a single system. Using data from 401 farmers in the Western and Ashanti regions of Ghana in 2022, the study found that more profitable farmers were more likely to diversify. Conversely, diversified farmers were likely to be more profitable than non-diversified farmers. It also found that the farmer's age, experience, farm area, and location of the farm impacted both the profitability and diversification status of farmers. Thus, it is suggested that policymakers should direct policies and programs to support the creation of alternative farm-based livelihoods for farmers.

This study deals with the application of an artificial neural network (ANN) model to predict power consumption for utilizing seawater source heat pumps of recirculating aquaculture system. An integrated dynamic simulation model was constructed using the TRNSYS program to obtain input and output data for the ANN model to predict the power consumption of the recirculating aquaculture system with a heat pump system. Data obtained from the TRNSYS program were analyzed using linear regression, and converted into optimal data necessary for the ANN model through normalization. To optimize the ANN-based power consumption prediction model, the hyper parameters of ANN were determined using the Bayesian optimization. ANN simulation results showed that ANN models with optimized hyper parameters exhibited acceptably high predictive accuracy conforming to ASHRAE standards.

본 연구의 목적은 컨테이너 육묘 시스템을 활용한 참외 접목 묘의 안정적인 생산 가능성을 평가하는 것이었다. 이를 위해, 컨테이너 육묘 시스템과 고온 조건의 플라스틱 온실에서 육묘 한 접수와 대목, 접목묘의 생육을 비교 분석하였다. 접목활착 후 육묘 환경에 따른 참외 접목묘의 생육과 묘소질을 0일, 4일, 7일, 11일, 14일째에 비교하였다. 컨테이너 육묘 시스템에서 는 주야간 온도를 25/20°C, 상대습도를 70%로 설정하여 재 배기간 동안 안정적으로 유지하였으며, 플라스틱 온실 내의 주야간 평균온도는 28.1/15.4°C로 주야간 온도차(DIF)가 더 크게 나타났다. 조사기간 동안 참외 접목묘의 초장은 플라스 틱 온실 육묘 처리구에서 컨테이너 육묘 시스템 처리구보다 더 길게 나타났다. 참외 접목묘 조직의 충실도는 지상부 건물 중을 초장으로 나누어 계산하였다. 육묘장에서 접목한 묘는 접목 후 7－10일 경과하여 활착이 완료되고 초장이 10cm 내 외일 때 출하하여 정식에 이용되게 된다. 본 연구에서 접목활 착 후 7일째에 컨테이너 육묘 시스템에서 재배된 묘의 충실도 는 44.9±2.64mg/cm으로 나타났으며, 플라스틱 온실 육묘 처 리구에서는 24.4±1.56mg/cm로 나타났다. SPAD 평균은 플 라스틱 온실 육묘에서 30.5, 컨테이너 육묘 시스템에서 41.1 로 측정되었다. 이러한 결과는 컨테이너 육묘 시스템의 활용 이 고온기 또는 저일조 시기와 같은 육묘 환경에서도 고품질 모종을 안정적으로 생산할 수 있는 것을 확인하였고, 인공광 을 이용한 육묘 시스템의 활용 범위가 앞으로 더 확대될 것으 로 기대된다.

스마트팜형 시설 딸기에 예찰 없이 작물 정식 초기에 천적을 먼저 적용하는 생태공학적 Natural Enemy in First (NEF) 기법이 총채벌레류 와 진딧물류의 밀도에 미치는 영향을 확인하였다. 대조구는 약제를 처리하여 비교하였다. NEF 처리구에서 총채벌레류와 진딧물류의 천적과 서식 처로 참멋애꽃노린재와 Portulaca sp.를 적용하여 작기 종료시점까지 해충의 밀도를 대조구와 유사하게 효과적으로 관리할 수 있었다.

한국에서 시설 딸기 해충을 방제하는 대표적인 방법은 살충제를 사용한 화학적 방법이다. 이는 농가에서 쉽게 접하고 처리 시기를 마음대로 조절할 수 있는 장점이 있지만, 방제 비용과 농업인부의 빈번한 화학살충제 노출이 큰 단점이다. 경주시 상평농원은 천적을 적극적으로 사용하는 농가로써 2020년부터 현재까지 4년간 4종의 천적 을 구매, 사육, 방사를 실시하였다. 방사한 천적은 점박이응애 방제용 칠레이리응애와 사막이리응애, 작은뿌리 파리 방제용 뿌리이리응애, 진딧물 방제용 콜레마니진딧벌이며, 농장의 규모는 재배동 1,250평, 육묘동 450평으 로 자가육묘를 하기에 1년 내내 딸기를 재배하는 농장이다. 본격적으로 천적을 활용하는 시기는 9월부터 이듬해 5월까지 약 9개월이다. 이 기간 동안 소요된 비용은 천적을 구매하고 자가사육하여 사용한 경우(154만원), 천적과 약제를 구매하여 같이 사용한 경우(240만원), 천적만 구매하여 사용한 경우(262만원), 약제만 처리(377만원) 순 으로 나타났다. 다만, 이 결과는 과학적으로 반복 및 재현 검증되지는 않았고, 각 농가의 천적과 해충의 생태에 대한 이해도와 작물 재배능력, 천적 사육능력에 따라 차이가 있을 수 있다.

이 논문은 동계작물 재배면적 배분 비율의 의사결정 요인과 그 영향을 파악하기 위한 재배면적 함수의 구축과 추정에 목적이 있다. 이를 위해 지난 30년 동안(1991~2021) 동계작물 생산 농가의 최적 면적 배분 과정에서 생산물 가격요인과 투입 요소 생산비 요인의 영향을 추정하였다. 분석 결과, 생산물 가격요인으로 작물의 자체 가격 상승은 재배면적을 증가시키고, 대체 작물의 가격 상승은 재배면적을 감소시키는 것으로 나타났다. 한편, 투입 요소 생산비 요인은 작물에 따라 증감의 방향이 혼재되어 영향을 미치는 것으로 나타났다. 따라서 가격 및 투입 요소 비용 변화로 인한 과잉 과소 생산을 방지하고 수급 안정을 도모하기 위해서는 주산지 및 지역별 작목변화와 생산량 예측이 선행되어 수급 정책 수립 시 적극적으로 활용할 필요가 있다.

The purpose of this study was to compare the efficiency of air and oxygen injected into the underwater non-thermal dielectric barrier discharge plasma (DBD plasma) device used to remove five types of antibiotics (tetracycline, doxycycline, oxytetracycline, clindamycin, and erythromycin) artificially contained in the fish farm discharge water. The voltage given to generate DBD plasma was 27.8 kV, and the measurement intervals were 0, 0.5, 1, 2, 4, 8, 16 and 32 minutes. Tetracycline antibiotics significantly decreased in 4 minutes when air was injected and were reduced in 30 seconds when oxygen was injected. After the introduction of air and oxygen at 32 minutes, 78.1% and 95.8% of tetracycline were removed, 77.1% and 96.3% of doxycycline were removed, and 77.1% and 95.5% of oxytetracycline were removed, respectively. In air and oxygen, 59.6% and 83.0% of clindamycin and 53.3% and 74.3% of erythromycin were removed, respectively. The two antibiotics showed lower removal efficiency than tetracyclines. In conclusion, fish farm discharge water contains five different types of antibiotics that can be reduced using underwater DBD plasma, and oxygen gas injection outperformed air in terms of removal efficiency.

This study was conducted to identify changes of insect compositions and diversity after construction of an onshore wind farm. We investigated insect fauna and compositions between a grassland deforested by the construction and a forest located at Yeongdeok and Yeongyang, Gyeongsangbuk-do, Korea. Insects were collected using a sweeping net and light trap. A total of 11 orders, 50 families, and 246 species, and 1,076 individuals were collected at study sites. By taxonomic group, Lepidoptera species were the most frequently found with 141 species, 417 individuals (38.8%), followed by Hymenoptera (20.6%), Hemiptera (16.2%), and Orthoptera (12.3%). There were also significant differences in insect species and community compositions between sites. Creating open-field deforested forests are beneficial for some insect groups such as Hymenoptera and Orthoptera. Our results suggest that deforesting by the construction of an onshore wind farm might affect the composition and diversity of insects. Results of this study provide basic data for research on onshore wind farms.

The annual number of odor complaints increased about 10 times over 14 years from 4,302 in 2005 to 40,854 in 2019, in Korea. Especially, livestock facilities account for more than 50% of the odor complaints and the swine farms account for the most odor complaints among livestock. It is therefore necessary to manage swine farms as the major odor emission source. In this study, a real-time odor monitoring system equipped with PTR-TOF-MS (proton transfer reaction time-of-flight mass spectrometric) was used to measure the odorous substances in two swine farms. Odorous substances emitted from outlets were sampled and measured at the two types of swine farms. In addition, the boundary spots were designated as measurement points. As a result, the rankings of the odorous substances in order, from highest to lowest, were ammonia, acetaldehyde, methyl mercaptan, fatty acids, etc. and the level of odor intensity was 0.8-4.4 at the outlet of the swine farms. The concentration at the boundary decreased between 1/100 ~ 1/10000 compared to the concentration emitted from outlets. Base on the results of evaluating odor activity values, Skatole and p-Cresol were estimated as major odor substances in swine farms.

To mitigate the environmental impacts of the energy sector, the government of South Korea has made a continuous effort to facilitate the development and commercialization of renewable energy. As a result, the efficiency of renewable energy plants is not a consideration in the potential site selection process. To contribute to the overall sustainability of this increasingly important sector, this study utilizes the Black-Scholes model to evaluate the economic value of potential sites for off-site wind farms, while analyzing the environmental mitigation of these potential sites in terms of carbon emission reduction. In order to incorporate the importance of flexibility and uncertainty factors in the evaluation process, this study has developed a site evaluation model focused on system dynamics and real option approaches that compares the expected revenue and expected cost during the life cycle of off-site wind farm sites. Using sensitivity analysis, this study further investigates two uncertainty factors (namely, investment cost and wind energy production) on the economic value and carbon emission reduction of potential wind farm locations.

The present trial verified the effects of spraying microbial agents on odor reduction in commercial pig farms of different operating sizes and barn types. Farms without microbial agent spraying and those sprayed with microbial agents at two different intervals were compared. The treatments included spraying of water alone every day or a mixture of water plus microbial agent at 24 and 72 h intervals. The experimental farms were divided according to size into 1,000-, 3,000-, and 5,000-head farms and according to barn type into gestation, farrowing, nursery, and grower-finisher farms. To compare odor concentration within each housing barn, ammonia and hydrogen sulfide gas levels were measured. The average concentrations of ammonia (p<0.01) and hydrogen sulfide (p<0.05) gas were the lowest in all types of farms sprayed with the microbial agent at a 24 h interval. In farms sprayed with the microbial agent at a 24 h interval, the decrease in ammonia concentration according to barn type was in the following order: farrowing (p<0.01) (11.0 to 1.8 ppm), nursery (p<0.05) (17.0 to 9.2 ppm), grower-finisher (15.3 to 8.8 ppm), and gestation (9.7 to 6.4 ppm) farms. Moreover, spraying the microbial agent at a 24 h interval significantly (p<0.01) decreased ammonia concentration from 19.9 to 10.4 ppm, from 11.1 to 4.1 ppm, and from 8.8 to 5.1 ppm in 5,000-, 3,000-, and 1,000-head farms, respectively. Overall, spraying microbial agents every day may be the most effective method to reduce odor in commercial pig farms.