• Korean Journal of Soil Science and Fertilizer
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• v.40 no.3
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• pp.173-180
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• 2007

Reclaimed tidal area is a great agricultural resource in the world. Improvement and utilization of reclaimed soil is an important measure for expanding land resource. This study was conducted to evaluate relative salt-tolerance of plants and its effect for improving saline soil. Eighteen tolerance plants were selected from China, Pakistan and Korea the climate of which is different. The emergence of different varieties in reclaimed soil was in order as FL478>Barnyard grass>Pokkali>Atriplex>Sesbania>Rumex>Alfalfa>Tall Fescue>Ryegrass>Sudan grass. Four varieties, Barnyard grass, Sesbania, Atriplex and Limonium were selected for soil improvement in reclaimed land. Cultivation of Sesbania, Barnyard grass and Atriplex were good to soil physico-chemical quality. Also these plants increased soil organic matter contents and reduced soil salt concentration. Organic matter contents of cultivated soils of Sesbania, Barnyard grass and Atriplex were $4.10g\;kg^{-1}$, $4.60g\;kg^{-1}$ and $2.81g\;kg^{-1}$ respectively. On the other hand organic matter content of uncultivated soils was $2.65g\;kg^{-1}$. As Sesbania and Barnyard grass were applied to cultivated soil like green manure, bulk density improved from $1.42Mg\;m^{-3}$ to $1.39Mg\;m^{-3}$.

• Korean Journal of Organic Agriculture
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• v.15 no.4
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• pp.399-411
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• 2007

Korean organic farming has been well developed over the last two decades. It demonstrates that the number of certificated farm for organic agriculture and products have been drastically increased in recent year. However, the organic farmers have thought that organic farming rely only on organic fertilizer and they don't keep organic farming principle in which organic farmer should enhance biological activity and crop rotation. This study was to compare nutrient input, recommendation, cropping system and organic product circulation between the early $20^{th}$ century and beginning of the $21^{st}$ century. The population of Korea has increased 7.3 times more than that of a century ago but cultivated land has been decreased during 100 years. The rice production in 2002 was 4.2 times higher than that of production in 1912. The input of N, P and K in 1907 on the basis of King's suggestion was 95.6kg/ha, 15.9kg/ha and 3.0kg/ha, respectively. Nitrogen came from excreta (40%), green manure (55%) and compost (5%) in the early 20th century. On the other hand, organic farmer input organic resources such as wood chip (30.1%), compost (27.8%), rice straw (14%) and others (25%) these days. In terms of nutrient balance calculated nutrient and absorption by plants, organic rice farmer apply excessive nitrogen and phosphorus to the soil. They was used to put $7{\sim}10$ times more nitrogen than that of a century ago. Nutrient recommendation was similar in N and P between early 20th century and early $21^{st}$ century. Farmers in both century did not rotate crops in the field. Today, organic farmers engaged in more continuous cultivation than in early 20th century. Farmers in the early $20^{th}$ century produced locally, consumed locally the agricultural products, but organic farmers in the $21^{st}$ century produce the organic product in the local farmland and consumed in the large city and also a lot of foreign organic products have been imported in recent year.

• Journal of Ecology and Environment
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• v.48 no.2
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• pp.182-195
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• 2024

Background: Invasive alien plant species (IAP) significantly threaten Nepal's protected areas and local communities. Understanding their distribution, impact, management, and utilization is essential for developing effective management strategies and sustainable utilization practices. The systematic literature review of publications from 2010 to 2023. The search was conducted through the database Nepal Journal online database (NepJOL) and Google Scholar, yielding an initial pool of 4,304 publication. After applying inclusion and exclusion criteria; we meticulously reviewed 43 articles for data extraction. Results: Seventeen IAP are found in protected area, Nepal with the highest prevalence observed in Koshi Tappu Wildlife Reserve, followed by Chitwan and Sukhlaphanta National Park. The most problematic species in terrestrial ecosystems are Mikania micrantha, Lantana camara, and Chromolaena odorata. The grassland ecosystems of wildlife habitats, primarily in the Terai and Siwalik regions, are the most invaded. Various management approaches are employed to mitigate the spread and impact of IAP, including mechanical methods such as uprooting, burning, and cutting. However, these methods are costly, and context-specific interventions are needed. The study also explores the potential use of IAP for economic, ecological, or cultural purposes, such as medicinal properties, energy production potential, and economic viability. Local communities utilize these plants for animal bedding, mulching, green manure, briquette, and charcoal production. Conclusions: Applying silvicultural practices alongside mechanical management is recommended to maintain a healthy terrestrial ecosystem and utilize the removed biomass for valuable products, thereby reducing removal costs and increasing income sources, potentially benefitting both local communities and wildlife in protected areas.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.90-104
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• 2001

This study is aimed to analyze and to evaluate the revegetation and soil conservation technology in desertification-affected sandy land, resulting from the project of "Studies on the desertification combating and sand industry development". Main native plants for combating desertification : The general characteristics of vegetation distribution in desertified regions are partially concentrated vegetation distribution types including the a) desert plants in low zone of desert or sanddune of depressed basin, b) salt-resistant plants around saline lakes, c) grouped vegetation with Poplar and Chinese Tamarix of freshwater-lakes, saline-lakes and river-banks, d) gobi vegetation of gravel desert and e) grassland and oasis-woods around the alluvial fan of rivers, etc. Generally, Tamarix ehinensis Lour., Haloxylon ammodendron Bunge., Calligonum spp., Populus euphratica Oliver., Elaeagnus angustifolia L., Ulmus pumila L., Salix spp., Hedysarum spp., Caragana spp., Xanthoceras sorbifolia Bunge., Nitraria tangutorum Bobr., Lespedeza bicolor, Alhagi sparsifolia Shap., Capparis spinosa L., Artemisia arenaria DC., etc. are widely distributed in desertified regions. It is necessary for conducting research in the native plants in desertified regions. Analysis of intensive revegetation technology system for combating desertification : In the wind erosion region, the experimental research projects of rational farming systems (regional planning, shelterbelts system, protection system of oasis, establishment of irrigation-channel networks and management technology of enormous farmlands, etc.), rational utilization technology of plant resources (fuelwood, medicinal plants, grazing and grassland management, etc.), utilization technology of water resources (management and planning of watershed, construction of channel and technology of water saving and irrigation, etc.), establishment of sheltetbelts, control of population increase and increased production technology of agricultural forest, fuelwood and feed, etc. are preponderantly being promoted. And in water erosion region, the experimental research projects of development of rational utilization technology of land and vegetation, engineering technology and protection technology of crops, etc. are being promoted in priority. And also, the experimental researches on the methods of utilization of water (irrigation, drainage, washing and rice cultivation, etc.), agricultural methods (reclamation of land, agronomy, fertilization, seeding, crop rotation, mixed-cultivation and soil dressing works, etc.) and biological methods (cultivation of salt-resistant crops and green manure and tree plantation, etc.) for improvement of saline soil and alkaline soil in desertified-lands are actively being promoted. And the international cooperations on the revegetation technology development projects of desertified-lands are sincerely being required.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.448-453
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• 2013

We investigated the occurrence of major pests, 4 species of moths (Grapholita dimorpha Busck, Carposina sasakii Matsumura, Archips breviplicanus Walsingham, Adoxophyes orana Fischer von Roslerstamm), apple aphid (Aphis spiraecola Patch), two spotted spider mite (Tetranychus urticae Koch) and parasitoids in pear orchard with hairy vetch and cutting weeds in Yesan, Chungnam province during the flowering season and summer depression season of hairy vetch, in 2012 and 2013. The occurrence of 4 species of moths in hairy vetch plot and cutting weeds (major is finger grass, Digitaria sanguinalis, 80%) were little different but in case of apple aphid, the density in hairy vetch plot was just 95 aphids per stem at 20th June but low after then. The density of two spotted spider mite on pear leaf in hairy vetch plot was lower than in cutting weeds plot significantly. The number of parasitoids collected in hairy vetch plot during flowering season (May and June) were 398 and 798 in 2012 and 2013, respectively. The number of parasitoids collected in hairy vetch plot during summer depression season (July and August) were 114 and 172, respectively. But in cutting weeds plot, 9 and 22 in May and June, 8 and 5 in July and August. We didn't know either hairy vetch in pear orchard affected the occurrence of 4 species of moths, apple aphid and two spotted spider mite or not but was acted to be favorable for wasps, the natural enemies on the contrary. The improvement of chemical control systems through the selection of low chemicals to natural enemies with cover and green manure plants would turn effective pest management into a possibility.

• Research in Plant Disease
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• v.17 no.3
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• pp.405-409
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• 2011

Azolla Lam. is a small aquatic fern with deeply bilobed leaves, which are consisted of a thick greenish, with chlorophyll, upper (dorsal) lobe and a thinner, translucent lower (ventral) lobe, without chlorophyll, submerged in the water. Azolla blight was observed at a lotus pond. Mycological characteristics of the fungus associated with Azolla blight was immediately determined as Rhizoctonia sp. by the thickness and branching of hypha at right angles at the point toward the distal end of septa, with branching hypha is constricted. The fungus produced brown mycelia and dark brown sclerotia on PDA. The optimum temperature for mycelial growth and sclerotia formation were $25^{\circ}C$ and $30^{\circ}C$, respectively. The optimum temperature for fungal infection was $30^{\circ}C$, when spray inoculated. Phylogenetic analysis of rDNA-ITS revealed that the fungus was identified as Rhizoctonia solani (AG-1 IA) closest to one causing rice sheath blight disease. This is the first report on the blight disease of Azolla caused by R. solani in Korea.

• Korean Journal of Environmental Biology
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• v.34 no.3
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• pp.169-176
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• 2016

Although chemical fertilizers have a quick effect and broad applicability to agricultural fields, they have caused many problems like increasing soil acidity or decreasing soil organic matters. Environmental-friendly agriculture has been attempted in various ways such as organic agriculture, natural farming, low input and sustainable agriculture. The common interest of all environmental-friendly systems is to decrease burden to agricultural environment by low input of agricultural labor and materials. This study was conducted to estimate overwintering capacity and genetic distance among Chinese Milk Vetch (Astragalus sinicus, CMV) collections based on morphological characteristics and AFLP (Amplified fragment length polymorphism) analysis. Furthermore, the effect of CMV as green manure was observed in mix-cultured paddy fields with rice, sesame and sweet-potato. An another objective of this study was also to compare the pattern of weed occurrence in paddy fields with or without CMV and different rice transplanting times. The CMV collected from Paju district in central region of Korea was successively occurring through self-reseeding without artificial management. However, there was no noticeable difference in growth habit between Paju native CMV and introduced CMV from China which is currently used in farm fields. On the basis of multi-dimensional scaling and tree analyses, there are no significant difference of agricultural growth characteristics among Paju and chinese collections only excepting leaf angle and root length. The flowering time of Gurye collection was fast for 1 week as compared to other collections. AFLP that was commonly used for plant classfication, was applied to exam the genetic variation of CMV collections. Total 579 PCR products and 336 polymorphic fragments were generated using 8 primer pairs.

• Korean Journal of Environmental Agriculture
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• v.27 no.4
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• pp.343-348
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• 2008

To investigate the effects of incorporation of green manures (GM) into a sandy loam soil on growth, yield, and nutrient uptake of tomato (Lycoperiscon esculentum Mill.) and nutrient balances (input minus offtake of nutrients), five tomato production systems were compared under the condition of plastic film house: 1) a no input system (no additional amendment or inputs, 0-To-0-To); 2) a conventional system (application of N-P-K chemical fertilizers, Cf-To-Cf-To); 3) a leguminous GM-containing system (hairy vetch-tomato-soybean-tomato, Hv-To-Sb-To); 4) a graminaceous GM-containing system (rye-tomato-sudan grass-tomato, Ry-To-Sd-To); and 5) system mixed with leguminous and graminaceous GMs (rye-tomatosoybean- tomato, Ry-To-Sb-To). Here, hairy vetch and rye were cultivated as winter cover crops during late $Dec{\sim}late$ Feb and soybean and sudan grass were cultivated as summer cover crops during late $Jun{\sim}mid$ Aug. All of them cut before tomato planting and then incorporated into soil. Biomass of GMs was greater in summer season than that of winter season. Nitrogen amount fixed by a leguminous plants was about $126\;kg\;ha^{-1}$ per a cropping season, corresponding to 60% N level needed for tomato production, which was comparable to 50 and $96\;kg\;ha^{-1}$ fixed by rye and sudan grass. As a result, tomato yield of Hv-To-Sb-To system (legume GM treatment) was similar to Cf-To-Cf-To (conventional), but that in Ry-To-Sd-To system (graminaceous GM treatment) was not attained to a half level of conventional treatment. Nutrient budgets for N, P and K on the conventional farm were balanced or somewhat positive exception for minus-balanced K. Ry-To-Sd-To system showed a positive N, P and K budgets due to the depressed growth of tomato which is caused by high C/N ratio and low N-fixing capacity of the GMs. Inversely, those of Hv-To-Sb-To system were negative in all of N, P and K budgets because of increased growth and yield of tomato with high nitrogen-supplying capacity as well as low C/N ratio of leguminous GM. In conclusion, although conventional cultivation has an advantage in relation to N, P and K nutrient budgets rather than GM-incorporated systems, a leguminous GMs could be recommended as nitrogen reservoir and soil amendment because the yield of tomato between use of leguminous GM and conventional cultivation was not only significantly difference, but also GMs commonly reduce nutrient loss and improve microbial communities.

• Korean Journal of Agricultural Science
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• v.2 no.1
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• pp.125-130
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• 1975

This investigation was carried out to define the cultivation state of Ginseng seedling and to study the growth of important characters by location and correlations between characters, the results obtained are summarized as follows; 1. Most of farmers culitvating ginseng seedling had not any special consideration for the improvement of soil, and they applied green manure only as basic fertilizer but they did not apply chemical fertilizer. 2. Any efforts on the improvement of ginseng seed were not found. Seed was harvested from 3 years old ginseng plant. Seedling density was 1.8 cm by 2 cm. 3. Growth of all characters showed significant differences among farms. Coefficients of variation among individual seedling plants was largest at root diameter and smallest at root length. 4. Gromth of all characters without root diameter by planted location under the shadow was poor at front row, however root diameter was shortest at back row. 5. Significant high correlatons were rocognized between root diameter and stem diameter, between leaf blade and stem diameter and between leaf blade and leaf length, but stem length were not correlated with any characters. It is noticable that negative correlations were found between stem length and root diameter, between stem length and root length and between stem length and stem diameter.

• Journal of the Korean Society of International Agriculture
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• v.23 no.5
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• pp.546-551
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• 2011

Chrysanthemums, often called mums or chrysanths, belong to the genus Chrysanthemum, which includes about 30 species of perennial flowering plants in the family Asteraceae. We extracted DNA from Dendranthema grandiflorum ('Smileball') to construct a simple sequence repeat (SSR)-enriched library, using a modified biotin-streptavidin capture method. GS FLX (Genome Sequencer FLX System which provides the flexibility to perform the broad range of applications) sequencing (at the 1/8 run specification) resulted in 18.83 mega base pairs (Mbp) with an average read length of 280.06 bp. Sequence analyses of all SSR-containing clones revealed a predominance of di-nucleotide motifs (16,375, 61.5%) followed by tri-nucleotide motifs (6,616, 24.8%), tetra-nucleotide motifs (1,674, 6.3%), penta-nucleotide motifs (1,283, 4.8%), and hexa-nucleotide motifs (693, 2.6%). Among the di-nucleotide motifs, the AC/CA class was the most frequently identified (93.5% of all di-nucleotide types), followed by the GA/AG class (6.1%), the AT/TA class (0.4%), and the CG/GC class (0.03%). When we analyzed the distribution of different repeat motifs and their respective numbers of repeats, regardless of the motif class, of 100 SSR markers, we found a higher number of di-nucleotide motifs with 70 to 80 repeats; we also found two di-nucleotide motifs with 83 and 89 repeats, respectively, but their product lengths were within optimum size (297 and 300 bp). In future work, we will screen for polymorphisms of possible primer pairs. The results will provide a useful tool for assessing molecular diversity and investigating the population structure among and within Chrysanthemum species.