p-ISSN 1225-3537e-ISSN 2233-4173
Sung-Chang Hong, Jin-Ho Kim, Min-Wook Kim / Korean Journal of Environmental Agriculture / 2021 / v.40, no.3, 149-160
Abstract
Concerns have been raised about the impact of recent high concentrations of fine dust on human health. Ammonia(NH3) reacts with sulfur oxides and nitrogen compounds in the atmosphere to form ultrafine ammonium sulfate and ammonium nitrate (PM2.5). There is a growing need for accurate estimates of the amount of ammonia emitted during agricultural production. Therefore, in this study, ammonia emissions generated from the cultivation of leafy perilla in plastic houses were determined.
Cow manure compost, swine manure compost, and poultry manure compost each at 34.6 ton ha-1, the amount commonly used by farmers in the field, was sprayed on the soil surface. Just after spraying cow manure compost, swine manure compost, and poultry manure compost, the ammonia was periodically measured and analyzed to be 22.5 kg ha-1, 22.8 kg ha-1, and 85.2 kg ha-1, respectively. The emission factors were estimated at 70.0 kg-NH3 ton-N, 62.8 kg-NH3 ton-N, and 234.1 kg-NH3 ton-N, respectively. Most ammonia was released in the two weeks after application of the compost and then the amount released gradually decreased.
Therefore, it is necessary to improve the emission factor through a study on the estimation of ammonia emission by type of livestock manure and major farming types such as rice fields and uplands, and to update data on the production, distribution, and sales of livestock manure.
Yun-Gu Kang, Jae-Han Lee, Jin-Hyuk Chun, Taek-Keun Oh / Korean Journal of Environmental Agriculture / 2021 / v.40, no.3, 161-168
Biochar has ability to reduce N loss, increase crop yield, and sequestrate carbon in the soil However, there is still limited study concerning the interactive effects of various biochars on NH3 loss and plant growth. This study, therefore, was conducted to investigate the NH4+ adsorption characteristics of biochar derived from rice and maize residues.
By-products were pyrolyzed under oxygen-limited conditions at 300-700℃ for 1 hour and used for experiment of NH4+ adsorption in aqueous solution. The adsorption characteristics of biochar were studied using Langmuir isotherm. Biochar yield and hydrogen content decreased with increasing pyrolysis temperatures, whereas pH, EC, and total carbon content increased. The biochar pyrolyzed at lower temperatures was more efficient at NH4+ adsorption than those produced at higher temperatures. In addition, the RL values, indicating equilibrium coefficient were between 0 and 1, confirming that the result was suitable for Langmuir isotherm.
The maize stalk biochar pyrolyzed at 300℃ was the most efficient to adsorb NH4+ from the aqueous solution. Furthermore, the adsorption results of this experiment were lower than those of other prior studies, which were ascribed to different experimental conditions such as ingredients, and pyrolysis conditions.
Myung-Hyun Kim, Min-Kyeong Kim, Soon-Kun Choi, Jinu Eo, So-Jin Yeob, Jeong Hwan Bang / Korean Journal of Environmental Agriculture / 2021 / v.40, no.3, 169-178
The Ministry of Agriculture, Food and Rural Affairs is promoting agri-environment conservation program to induce farmers to participate in agricultural environment improvement and conservation activities. However, assessment tools based on scientific evidence are needed to determine the effectiveness of the program objectively and quantitatively. Therefore, this study was performed to develop plant indicators in order to efficiently evaluate the effects of the agri-environment conservation program promoted by the Ministry of Agriculture, Food and Rural Affairs.
The survey was conducted in five regions (Hampyeong, Boryeong, Mungyeong, Hongseong, and Sangju) participating in the agri-eonvironment conservation program. In each region, twenty paddy fields were investigated (ten paddy fields included in the program and ten paddy fields not included in the program). A total of 231 taxa vascular plants were identified in the paddy fields that were included in the agri-environment conservation program, and a total of 177 taxa were identified in the paddy fields that were not included. The average species number occurred on each field was 55.8 taxa in the fields included in the program, and 35.0 taxa in the fields not included in the program. The difference in occurring plants between two groups was found to be more higher in perennial plants than in annual plants. We selected the six groups as indicator plants through five criteria such as perennial plants and broadly occurring species, etc. to verify the effectiveness of the agri-environment conservation program: Taraxacum spp., Ixeris spp., Viola spp., Platago spp., Calystegia spp., and rare and endagered species. There was a high positive correlation between the score calculated using these indicator plants and the total number of plants species.
This study suggests that it is possible to evaluate the agro-ecological environment by using indicator plants. The selected indicator plants can be effectively used to verify the effectiveness of projects such as agri-environmental conservation programs in the future.
Hyosun Park, So Hee Yang, Euyeon Kim, Yeonjong Koo / Korean Journal of Environmental Agriculture / 2021 / v.40, no.3, 179-185
Tomato genome editing using CRISPR-Cas9 is being actively conducted in recent days, and lots of plant researches have been aiming to develop high valued crops by editing target genes without inserting foreign genes. Many researchers have been involved in the manipulation of the crop ripening process because fruit ripening is an important fruit phenotype for increasing fruit shelf life, taste, and texture of crops. This paper intends to evaluate target sgRNA to edit the two ripening-related genes encoding pectate lyase (PL) and phytoene synthase (Psy) with the CRISPR-Cas9 system.
The CRISPR-Cas9 expression vector was cloned to target the PL (Solyc03g111690), Psy1 (Solyc03g031860), and Psy2 (Solyc02g081330) genes, which are the ripening genes of tomatoes. Tomatoes injected with Agrobacterium containing the CRISPR-Cas9 expression vector were further cultured for 5 days and used to check gene editing efficiency. As a result of the target gene sequence analysis by the next generation sequencing method, gene editing efficiency was calculated, and the efficient target location was selected for the PL and Psy genes.
Therefore, this study was aimed to establish target sgRNA data that could have higher efficiency of the CRISPR-Cas9 system to obtain the delayed ripening phenotype of tomato. The developed method and sgRNA information is expected to be utilized in the development of various crops to manage its ripening processes.
Euyeon Kim, So Hee Yang, Hyosun Park, Yeonjong Koo / Korean Journal of Environmental Agriculture / 2021 / v.40, no.3, 186-193
Before generating transgenic plant using the CRISPR-Cas9 system, the efficiency test of sgRNAs is recommended to reduce the time and effort for plant transformation and regeneration process. The efficiency of the sgRNA can be measured through the transient expression of sgRNA and Cas9 gene in tomato cotyledon; however, we found that the calculated efficiency showed a large variation. It is necessary to increase the precision of the experiment to obtain reliable sgRNA efficiency data from transient expression.
The cotyledon of 11th, 15th, 19th, and 23rd-day-old tomato (Solanum lycopersicum cv. Micro-Tom) were used for expressing CRISPR-Cas9 transiently. The agrobacterium harboring sgRNA for targeting ALS2 gene of tomato was injected through the stomata of leaf adaxial side and the genomic DNA was extracted in 5 days after injection. The target gene edition was identified by amplifying DNA fragment of target region and analyzing with Illumina sequencing method. The target gene editing efficiency was calculated by counting base deletion and insertion events from total target sequence read.
The CRISPR-Cas9 editing efficiency varied with tomato cotyledon age. The highest efficiency was observed at the 19-day-old cotyledons. Both the median and mean were the highest at this stage and the sample variability was also minimized. We found that the transgene of CRISPR-Cas9 system was strongly correlated with plant leaf development and suggested the optimum cotyledon leaf age for Agrobacterium-mediated transfection in tomato.
Kathyleen Nogrado, Gwang-Su Ha, Hee-Jong Yang, Ji-Hoon Lee / Korean Journal of Environmental Agriculture / 2021 / v.40, no.3, 194-202
Towards achievement of sustainable agriculture, using microbial inoculants may present promising alternatives without adverse environmental effects; however, there are challenging issues that should be addressed in terms of effectiveness and ecology. Viability and stability of the bacterial inoculants would be one of the major issues in effectiveness of microbial pesticide uses, and the changes within the indigenous microbial communities by the inoculants would be an important factor influencing soil ecology. Here we investigated the stability of the introduced bacterial strains in the soils planted with barley and its effect on the diversity shifts of the rhizosphere soil bacteria.
Two different types of bacterial strains of Bacillus thuringiensis and Shewanella oneidensis MR-1 were inoculated to the soils planted with barley. To monitor the stability of the inoculated bacterial strains, genes specific to the strains (XRE and mtrA) were quantified by qPCR. In addition, bacterial community analyses were performed using v3-v4 regions of 16S rRNA gene sequences from the barley rhizosphere soils, which were analyzed using Illumina MiSeq system and Mothur. Alpha-and beta-diversity analyses indicated that the inoculated rhizosphere soils were grouped apart from the uninoculated soil, and plant growth also may have affected the soil bacterial diversity.
Regardless of the survival of the introduced non-native microbes, non-indigenous bacteria may influence the soil microbial community and diversity.
Se-Yeon Kwak, Sang-Hyeob Lee, Aniruddha Sarker, Hyo-Young Kim, Byung-Gon Shin, Jang-Eok Kim / Korean Journal of Environmental Agriculture / 2021 / v.40, no.3, 203-210
Pesticides can persist in soil due to multiannual uses. To decrease the concerns for potential carry-over of such residues from treated soil during preceding crop cultivation to non-target crops grown in rotation, an uptake study of procymidone was conducted under the actual cultivation conditions in Korea.
Procymidone was sprayed twice by foliar application with recommended and double dose according to the safe use guidelines for Korean cabbage up to 14 days before harvest. Arable land was kept fallow for 4 days after harvesting Korean cabbage, and spinach was cultivated as a succeeding crop. Initial residues in soil were 5.670-14.175 mg/kg that were degraded to 3.098-4.555 mg/kg until harvest of Korean cabbage, and then persisted at 1.026-1.300 mg/kg by spinach harvest. Procymidone residues in edible part of succeeding crops from soil uptake were in range of 0.020-0.048 mg/kg for recommended dose and 0.055-0.116 mg/kg for double dose. Root concentration factor (RCF) values of procymidone at different concentration ranged from 0.053 to 0.123, and translocation factor (TF) ranged from 0.176 to 0.768 for spinach. The value of TF was higher than RCF, indicating that the capability of translocation to shoot was relatively higher than that of root uptake and accumulation.
Procymidone applied on Korean cabbage can be carried-over to spinach and detected at a level similar to MRL (0.05T mg/kg). Therefore, this study suggests a follow-up study for establishment of plant back interval (PBI) of succeeding crops reflecting the actual agricultural conditions as this study.
Min-Wook Kim, Jin-Ho Kim, Kyeong-Sik Kim, Sung-Chang Hong / Korean Journal of Environmental Agriculture / 2021 / v.40, no.3, 211-218
Fine particulate matter (PM2.5) is produced by chemical reactions between various precursors. PM2.5 has been found to create greater human risk than particulate matter (PM10), with diameters that are generally 10 micrometers and smaller. Ammonia (NH3) and nitrogen oxides (NOx) are the sources of secondary generation of PM2.5. These substances generate PM2.5 through some chemical reactions in the atmosphere. Through chemical reactions in the atmosphere, NH3 generates PM2.5. It is the causative agent of PM2.5. In 2017 the annual ammonia emission recorded from the agricultural sector was 244,335 tons, which accounted for about 79.3% of the total ammonia emission in Korea in that year. To address this issue, the agricultural sector announced the inclusion of reducing fine particulate matter and ammonia emissions by 30% in its targets for the year 2022. This may be achieved through analyses of its emission characteristics by monitoring the PM2.5 and NH3.
In this study, the PM2.5 concentration was measured real-time (every 1 hour) by using beta radiation from the particle dust measuring device (Spirant BAM). NH3 concentration was analyzed real-time by Cavity Ring-Down Spectroscopy (CRDS). The concentrations of ozone (O3) and nitrogen dioxide (NO2) were continuously measured and analyzed for the masses collected on filter papers by ultraviolet photometry and chemiluminescence.
This study established air pollutant monitoring system in agricultural areas to analyze the NH3 emission characteristics. The amount of PM2.5 and NH3 emission in agriculture was measured. Scientific evidence in agricultural areas was obtained by identifying the emission concentration and characteristics per season (monthly) and per hour.
Sun-Il Lee, Seong-Soo Kang, Eun-Jung Choi, Hyo-Suk Gwon, Hyoung-Seok Lee, Jong-Mun Lee, Sang-Sun Lim, Woo-Jung Choi / Korean Journal of Environmental Agriculture / 2021 / v.40, no.3, 219-230
Biochar is a solid material converted from agricultural biomass such as crop residues and pruning branch through pyrolysis under limited oxygen supply. Biochar consists of non-degradable carbon (C) double bonds and aromatic ring that are not readily broken down by microbial degradation in the soils. Due to the recalcitrancy of C in biochar, biochar application to the soils is of help in enhancing soil carbon sequestration in arable lands that might be a strategy of agricultural sector to mitigate climate change.
Data were collected from studies on the effect of biochar application on soil C content conducted in East Asian countries including China, Japan and Korea under different experimental conditions (incubation, column, pot, and field). The magnitude of soil C storage was positively correlated (p < 0.001) with biochar application rate under field conditions, reflecting accumulation of recalcitrant black C in the biochar. However, The changes in soil C contents per C input from biochar (% per t/ha) were 6.80 in field condition, and 12.58 in laboratory condition. The magnitude of increment of soil C was lower in field than in laboratory conditions due to potential loss of C through weathering of biochar under field conditions. Biochar production condition also affected soil C increment; more C increment was found with biochar produced at a high temperature (over 450℃).
This review suggests that biochar application is a potential measures of C sequestration in agricultural soils. However, as the increment of soil C biochar was affected by biochar types, further studies are necessary to find better biochar types for enhanced soil C storage.
Young Hyun Kim, Se Jin Oh, Donghyuk Kum, Minhwan Shin, Dongjin Kim, Sang Soo Lee / Korean Journal of Environmental Agriculture / 2021 / v.40, no.3, 231-238
Metal contamination of farmlands nearby abandoned mines is a serious environmental problem. This study was conducted to evaluate the efficiency of stabilizers on different type of the soils contaminated with metals.
The texture of silt loam soil initially contaminated with heavy metal was artificially adjusted to loam and sandy loam by adding sand, and the soil organic matter content (1.5%) was also altered by adding peat to the soils at 3.5 and 8.0%. The soils were mixed with 3% (w/w) of each limestone, dolomite, and steel slag. For the soils with different textures, the bioavailability of As was found to be the lowest in sandy loam compared to others metals such as Cu, Pb, and Zn. The efficacy of limestone and dolomite was not significantly different compared to the soils having different organic matter contents, but the stabilization efficiency of steel slag increased as the soil organic matter content increased. Moreover, stabilizers showed inhibition effect on the uptake of metals to plant.
The stabilizers were found as effective materials to immobilize metals in soil and to decrease plant uptake of metals. Studies are needed to deeply elucidate the interaction between influencing factors and various stabilizers.
