• Korean Journal of Soil Science and Fertilizer
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• v.49 no.1
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• pp.7-11
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• 2016

Winter crops have been recognized as an alternative to soil management for fertility and crop productivity in paddy soil. Recently, rape has been produced at winter season and there is little research results on reduction of N fertilizer by adding rape residues for rice cultivation. In this study, we investigated the productivity and quality of rice by applying with 0, 27, 63, $90kg\;ha^{-1}$ of N fertilizer after input of rape residues into soil for two years. The highest yield of rice was average $4.68Mg\;ha^{-1}$ at the treatment applied with the $90kg\;N\;ha^{-1}$ with rape residue. It was reduced to N rate from 31.6 to $43.2kg\;N\;ha^{-1}$ in comparison to $4.53Mg\;ha^{-1}$ of maximum yield in treatment added $90kg\;N\;ha^{-1}$ with rape. Amylose content in rice was similar among treatments with/without rape residue, but protein content was lower in treatment with rape residue than in those without rape residue. In conclusion, input of rape residue in rice cultivation could be alternative to reduction of N fertilization and improvement of quality by adjusting rice productivity in paddy soil under cropping system.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.109-114
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• 2010

Rape residue as green manure is an emerging alternative of chemical fertilizer to improve soil quality and crop productivity. Objective of this research was to evaluate the effectiveness of rape residue as green manure on reduction of chemical fertilizer and suppression of weed occurrence in rice-rape double cropping system. Greenhouse experiment was conducted with four treatments: the combination of rape residue and three different N application rates (0, 30 and 70% of recommended application rate (7.8 kg N $10a^{-1}$)) and 100% chemical fertilizer as a control. No difference in rice clum length was observed for all treatments, while panicle length was highest in a treatment of rape residue+70% chemical fertilizer (Rape+70%CF). In addition, rice grain weight at a Rape+70%CF treatment increased by 19% compared to the control. This treatment also reduced weed density and biomass by 58 and 53%, respectively, compared to the control. Our results suggest that use of rape residues as green manure is an environment friendly and effective way to reduce chemical fertilizer and to enhance crop productivity in rice-rape double cropping system in Korea.

• Korean Journal of Food Science and Technology
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• v.42 no.6
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• pp.643-647
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• 2010

This research was carried out to investigate residues of neomycin, streptomycin, dihydrostreptomycin, amitraz, 2,4-dimethylaniline (one of amitraz's metabolites), and coumaphos in honey in order to intensively control their use following the establishment of Korean maximum residue limits (MRLs) for veterinary drugs in honey in 2007. To monitor for residues, 110 honeys and food products with honey were collected and analyzed. The collected honeys included acasia, mixed flower, chestnut, rape flower, jujube, and native types. Neomycin, streptomycin, dihydrostreptomycin, oxytetracycline, and amitraz were not detected among samples. Coumaphos was found in the Korean acasia honey at 0.02 mg/kg, but its concentration was under the MRL (0.1 mg/kg) for coumaphos. According to the results, there were no violations of the Korean MRLs of veterinary drugs in honey.