• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.3
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• pp.299-304
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• 1983

It has been ascertained by a few researchers that soil conditions under which the rice plants were cultivated have some effects upon the root formation of the rice plants. But, much is not known about the root formation of the rice plants cultivated in the saline paddy fields. The goal of the present investigation is to study morphological effects of the soil salinity on the development of the rice root system. The following results were obtained: 1. Under the conditions of higher soil salinity, root systems developed well at surface soil, however, root systems developed well and distributed evenly through surface and sub-soil at the saline fields where soil salinity was lower. 2. The rice plants cultivated in the higher soil salinity form less crown roots than the rice plants which cultivated at the lower soil salinity. 3. As for the formation of the stunted roots, it was found out that relatively rice plant cultivated in higher soil salinity forms more stunted roots than the rice plants cultivated in lower soil salinity. 4. The crown root cultivated in the higher soil salinity forms more lateral roots per unit langth than the root cultivated in lower soil salinity. 5. As for the root hair formation, the crown root cultivated in higher soil salinity bears less haired epidermis and shorter root hairs than the root cultivated in lower soil salinity.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.1
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• pp.36-42
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• 2007

Korean paddy soils have long been almost uniformly managed throughout the whole country with flooded, deep tillage, puddlling, transplanting, and uncovering after harvest. Management of soil organic carbon could be more important in the sources of green house gases. However, soil organic carbon dynamics were not been studied for Korean paddy soils. Therefore, we evaluated the changes in soil organic carbon (SOC) of paddy soils between 1999 and 2003 at the same locations nationwide except islands. Soil organic carbon tends to increase in Inceptisols, which is predominant soil order for Korean paddy soils, from 1999 to 2003. Soil organic carbon increases in topographically plain paddy soils was greater than in valley soils, and was considerably high in predominant types of paddy soils (i.e., well adapted paddy soils, sandy paddy soils, and poorly drained paddy soils) but low and stable in the saline paddy soils. We also found that clay paddy soils are greater in soil organic carbon than sandy paddy soils. Through this study, we concluded that a proper management of paddy soils could contribute to soil organic carbon storage, which imply that the Korean paddy soils could help to enhance carbon dioxide sequestration via soil organic matter into the soil.

• Journal of Plant Biology
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• v.12 no.1
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• pp.7-14
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• 1969

Korea has a lots of margin for security of farm land from her coastal region. The area of saline soil may be reached about 10% of present farm land if the reclamation works are finished. This paper was conducted as a part of studying the possibilities of desalination of saline soil through the experiment of some halophytes. The halophytes in this works were Salicornia herbacea L., Suaeda glauca Bunge, chenopodium acuminatum Willd, and Scirpus triquerter L. Of the above halophytes, Salicornia was proved the most effective plant for desalination of saline soil referring to the following results; 1) The seasonal uptake of chloride by Salicornia was the highest of all. However, the general tendencies of all plants showed a decrease on August. 2) Salinity of soil showed the lowest value on the site where Salicornia was grwon densely. Comparing the other sites grouped by age of saline soil with the above site, the salinity of rice-paddy (10 years after reclamation) is similar to those of the site wehre Salicornia were as well as the 50 cm below the surface soil. 3) The maximum water holding capacity of surface soil appeared in the site of Salicornia, but in 50 cm below the surface, the maximum water holding capacity are almost on equat terms having no connection with the age of saline soil. Soil pH, other chemical compositions such as organic matter, magnesium, potassium, phosphorous, and nitrate were determined to elucidate the relationship between the changes of soil properties and chemical uptakes by certain halophytes. It is assumed that the above chemical compositions are frequently affected by the factors such as coastal circulation of salts, exchangeable base, microbial growth, climatic conditions, and irrigation of water.

• Proceedings of the Korean Society of Crop Science Conference
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• 2006.04a
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• pp.258-259
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• 2006

• Proceedings of the Korean Society of Crop Science Conference
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• 2006.04a
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• pp.260-261
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• 2006

• Korean Journal of Environmental Agriculture
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• v.29 no.1
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• pp.33-38
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• 2010

To improve the existing nitrogen recommendation method based on chemical properties of soils and to establish new recommendation rates of nitrogen fertilizer due to different types of soils, the application rates of nitrogen fertilizer were examined in different soils of 12 experimental rice paddy fields. The application rates of nitrogen fertilizer estimated by soil-testing were higher than the rates of nitrogen standard recommendation that has been used. The application rates for minimum rice productivity ranged from a low of 168 kg/10a in sandy soil to a high of 315 kg/10a in saline soil. Amounts of nitrogen absorption in rice were proportional to the application amounts of nitrogen fertilizer in soils. Nitrogen use efficiency was the highest, 36.7%, in immatured paddy field and it was inversely proportional to the application amounts of nitrogen. the rice tasty value was the highest in the soils without nitrogen application, and also it was the lowest in the saline soils with or without nitrogen application. As comparing with the nitrogen application rates obtained by the existing nitrogen recommendation method, optimal nitrogen application rates estimated by the standardization of nitrogen application efficiency rate, environmental index, and rice quality were 1.0 fold in the well adapted soil and sandy soil fields, 0.92 fold in the immatured soil field, and 0.83 fold in the saline soil field.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.3
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• pp.269-274
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• 1987

A laboratory experiment was conducted to find out the effect of inoculation with plant growth of associative $N_2$-fixing bacteria on the combination of eight different rice seedling with seven different associative $N_2$-fixing bacteria in which were isolated and identified from grasses and rice in saline and reclaimed saline paddy soil. Those were examined in N-free axenic culture medium. The result of this experiment exemplified the contribution of associative $N_2$-fixing bacteria to their host plant were varied much by the combination of rice cultivars and bacterial strains. Acetylene reduction ($N_2$-fixation) activity seems to be more variable with respect to the combination of rice cultivars and bacterial strains. The relationship between acetylene reduction activity and rice performance such as dry matter weight, plant height, root length, and number of root were statistically insignificant. However, in comparision with the control, the dry matter yield of Annapuruna was increased by inoculation of all the seven bacteria strains. Among the seven rice cultivars, the average acetylene reducing activity was the highest in Annapuruna, and Shingwang, and the lowest in IR-8 inoculated with Pseudomonas sp H8. Among the seven bacterial strains the highest acetylene reducing activity was obtained by the combination of Shingwang with Pseudomonas sp H8.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.4
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• pp.359-367
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• 1987

A method for evaluating bacterial chemotactic responses toward several single of combined sugars and sterile mucilage from the different rice cultivars had been tested. Bacterial genus of Azospirillum, Pseudomonas and Agrobacterium were specially identified from the histosphere of different rice cultivars and graminea grasses in saline and reclaimed saline paddy soil. To evaluate chemotaxis of these strains a modification of Fendrik channel method was used. Under this condition Azospirillum lipoferum Ecc 3-1 reacted stereoisomerically fomulating the single migration ring while Agrobacterium radiobacter Ecc 1-1 and Pseudomonas sp Ecc 4-1 did not. Strains specificities of chemotaxis to the single sugar such as D(+)-glucose and D(+)-fructose were less prominent than malic and citric acid. Chemotactic responses to the combined sugar such as D-galacturonic acid and the L-aspartate were found high attracting reaction than other combined sugars. Chemotaxis of associative $N_2$-fixing bacteria to the root exudates of different rice cultivars were differed among bacterial strains and rice cultivars.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.193-197
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• 1987

Associative heterotrophic nitrogen fixing bacteria were identified by immunodiffusion method in the histosphere of Planta-ginaceae, Caryophllaceae, Gramineae, and two types of rice cultivars. Twenty four strains associative heterotrophic bacteria with high ARA (more than 10nmole/tube/hr) were isolated from the histosphere of grasses and rice.* Those strains were related with 8 species of Azospirillum, 11 species of Pseudomonas, 2 species of Klebsiella and 2 species of Agrobacterium. Among them Azospirillum sp. and Pseudomonas sp. were predominant in histosphere of grasses and rice cultivars. From the histosphere of Oryza sativa, and Sagina maxima, the strains of Azospirillum, Pseudomonas, Klebsiella, and Agrobacter were identified while Pseudomonas was identified from Ischaemum anthephoroides, Plantago lanceolata, Miscanthus sacchuriflorum, and only Azospirillum was identified from Zoisia sinica, respectively. Associative nitrogen fixing heterotrophic bacteria were more abundant in the histosphere of Oryza sativa and Sagina maxima than that of other grasses grown in saline and reclaimed saline paddy soil.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.259-262
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• 2002

Relationship between yield and palatability value measured by vice taster among 9 rice varieties was investigated to obtain basic information for production of rice with high quality in reclaimed paddy field. The rice yield showed a highly negative correlation with palatability value of milled rice (r=-0.49$^{**}$). The varieties of high palatability value tend to show low yield. The protein content of milled rice grown in reclaimed paddy field was higher than 7.5% mainly due to heavy fertilization of nitrogen and irrigation of eutrophicated water, The rice varieties such as Daeanbyeo, Jinpumbyeo and Sindongjinbyeo were recommendable only for higher yield, but in view of rice quality, Kwanganbyeo, Surabyeo and Nampyoengbyeo were more recommendable because of their lower protein content and higher palatability value.e.