• Korean Journal of Environmental Agriculture
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• v.36 no.2
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• pp.67-72
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• 2017

BACKGROUND:Cultivation of alternative crops in paddy fields is necessary because of the decrease in rice consumption and the increase in excess stock of rice. The study was conducted to investigate the effects of alternative crops cultivation in paddy fields on soil physico-chemical characteristics and crop yield. METHODS AND RESULTS: Soybean (Glycine max), red-clover (Trifolium pratense), and water convolvulus (Ipomoea aquatica) were selected for alternative crops in the first and/or second year and rice was planted in the third year. When alternative crops were cultivated in the previous year, soil bulk density, soil hardness, and water content were lower than those for rice cultivation. Water-depth decreasing rate and aggregate content were greater for the upland-upland-paddy cropping system than upland-paddy-paddy cropping system. Cultivation of red-clover and water convolvulus for two years resulted in the high soil organic matter content. In the third year, available phosphate, exchangeable potassium, and soil cation exchange capacity were relatively high when soybean was cultivated in the previous year. In the first year, water convolvulus cultivation showed greater productivity than red-clover cultivation while the opposite pattern was found in the second year. Rice yield in the third year was greater for soybean or red-clover as a previous crop than for water convolvulus as a previous crop. CONCLUSION: The results suggest that cultivation of alternative crops in paddy fields can improve soil physical properties including bulk density, hardness, water content, and aggregate content as well as rice productivity.

• Research in Plant Disease
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• v.19 no.4
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• pp.294-299
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• 2013

To select resistant vegetables against two species of root-knot nematodes, M. incognita and M. arenaria, 39 vegetables belongs to 7 families, 13 genera, 25 species were screened in greenhouse pot test. Susceptible vegetables to both nematodes were amarath and leaf beet in Amaranthaceae, Malabar spinach in Basellaceae, Moroheiya in Tiliaceae, and Water-convolvulus in Convolvulaceae, Pak-choi in Brassica campestris var. chinensis, Tah tasai in B. campestris var. narinosa, B. campestris var. chinensis x narinosa, Leaf mustard, Mustard green in B. juncea, Kyona in B. juncea var. laciniate, Choy sum in B. rapa subsp. arachinenesis, Kairan in B. oleracea var. alboglabra, Arugula in Eruca sativa, Garland chrysanthemum in Chrysanthemum coronarium, Endive in Cichorium endivia, Artichoke in Cynara cardunculus var. scolymus, Lettuce in Lactuca sativa. Resistant to M. arenaria but susceptible to M. incognita were B. oleracea cv. Matjjang kale, B. oleracea var. gongyloides cv. Jeok kohlrabi, and C. intybus cv. Radicchio. Resistant vegetables to both nematodes were C. intybus cv. Sugar loaf, Grumoro, Radichio treviso, B. oleracea cv. Manchu collard, Super matjjang, B. oleracea italica, B. oleracea var. botrytis italiana, and Perilla in Lamiaceae. Vegetables resistant to both species of root-knot nematodes could be used as high-valued rotation crops in greenhouses where root-knot nematodes are problem.

• Ecology and Resilient Infrastructure
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• v.7 no.3
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• pp.145-159
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• 2020

Wetlands are vulnerable to biological invasion by alien species, because they function as sinks that accumulate excess water, sediments, nutrients, and other contaminants from the surrounding watersheds by disturbance. In this study, to understand the status and characteristics of the alien plants based on the type of wetlands, we classified 24 ecologically outstanding wetlands and analyzed the status of alien flora. A total of 130 alien plants were found in the wetlands, accounting for 11% of the total plant species. Among them, the Asteraceae species was the most diverse, with 40 species. Erigeron annuus and Oenothera ordorata had the highest frequency of occurrence. The species richness of alien plants in the riverine and lacustrine wetlands (average: 30 species) was higher than that in the mountainous palustrine wetlands (average: 10 species). The same results were found in the naturalization index, urbanization index, and ratio of annuals and biennials, which indicate the degree of artificial interference. In the cluster analysis, the riverine and lacustrine wetlands were combined, and only the mountainous palustrine wetlands were separated. The number of alien plants is remarkably low in the mountainous palustrine wetlands, and it is considered to be the influence of Erigeron strigosus, Symphytum officinale, and Bilderdykia convolvulus, not found in the other types of wetlands. In particular, invasive alien plants such as Aster pilosus, Ambrosia trifida, Sicyos angulatus, Ambrosia artemisiifolia var. elatior were found intensively in the riverine wetlands. Therefore, it is considered that a methodical management is urgently required considering the dispersal of alien plants in the riverine and lacustrine wetlands with high artificial interference.