• Korean Journal of Soil Science and Fertilizer
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• v.21 no.4
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• pp.443-449
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• 1988

The effects of rice-straw annual application on nitrogen fixing microbial flora in the soil of paddy fields and their biological activities were investigated. Experiments were performed in both NPK fertilizer applied soil and rice-straw applied soil of Agricultural Station in Aomori-ken, Japan. The following results were obtained. 1. The ARA by phototrophs was significantly increased in both soil plots. From the soil plot in which 300ppm-nitrogen was applied, the increase of ARA began to be seen from three weeks later. On the other hand, 33ppm-nitrogen applied soil plot and non-nitrogen applied soil plot showed the ARA increase from the beginning. The amount of ARA by non-phototrophs was only one-tenth of that by phototrophs. 2. For the first three weeks, the phototrophic bacteria (mainly Rhodopseudomonas) were predominant in both soil plots. Since then, as the ARA rapidly increased, the proliferation of blue-green algae forming heterocysts was remarkably promoted. Such effects were more distinct in the rice-straw annually applied soil plot than in the NPK fertilizer annually applied soil plot. 3. The degree of proliferation of blue-green algae depended on the amount of applied nitrogen. While Anabaena, Nostoc and Cylindrospermum were largely proliferated in the non-nitrogen applied soil plot, Cylindrospermum and Calothrix were in the 33ppm-nitrogen applied soil plot, but Calothrix tended to predominated in the 100ppm-nitrogen applied soil plot.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.105-112
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• 2010

Applications of plant residues and green manures generally improve the properties of soil under conventional farming system. Therefore, we investigated the improvement of selected soil physical properties, bulk density, porosity, and water content, soil penetration resistance, and soil microbial biomass carbon (SMBC) content as affected by different management practices: 1) conventional tillage without rice straw or green manure crop treatment (TNT, check plot), 2) no-tillage amended with rice straw (NTRS), 3) no-tillage amended with rye (NTR), 4) no-tillage amended with Chinese milk vetch (NTCMV), 5) no-tillage without rice straw or green manure crop treatment (NTNT), The values of bulk density, porosity, and water content ranged from 1.22 to 1.37 Mg $m^3$, from 48.3 to 54.0%, and from 35.0 to 40.2%, respectively. The management practices might positively influence the changes in the selected soil properties, especially in the second experimental year. The soil penetration resistance and SMBC content were also improved after applying rice straw and green manure crops as comparing with TNT. Therefore, applications of the rice straw and green manure crop management practices under no-tillage system positively influenced soil physical properties and soil microbial activities in paddy field.

• Journal of Ginseng Research
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• v.14 no.3
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• pp.427-431
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• 1990

To search for substituents of greens, several organic materials such as rice straw, barley straw, corn stem and manufactured compost were applied in a ginseng cultivating field. The yields of six year old ginseng harvested in the rice straw, barley strait and corn stem treated field were similar to or higher than that of the greens treated one. The varied amount of applied substituents resulted in a yield change, but statistical linearity was not found. The growth of ginseng aerial part and soil physicochemical property in the field fortified with these substituents showed similar results to those of the greens treated one. So, it is though that these organic materials can substitute for greens.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.6
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• pp.351-356
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• 2006

A long-term experiment was initiated in 1979 at Experiment Farm of Honam Agricultural Research Institute, to investigate the effects of continued use of organic matter (rice straw and compost) along with different levels of nitrogen fertilizer in rice cultivation. The soils of experimental plots is classified as Jeonbug series developed on Fluvio-marine deposits. The application rates of rice straw and compost were 5 Mg/ha/year and 10 Mg/ha/per year, respectively. The fertilizer N application rates per season were 0, 100, 150, 200, and 250 kg/ha. In 2002, after 24 years of experiment, the effect of different treatments on soil pH, characteristics soil organic matter, soil N and P were investigated. The results of the study is summarized as following. The continue use of organic matter tended to lower the soil pH, to increase organic matter and available phosphate contents. The rice straw tended to lower soil pH more than compost, while the effect of compost was greater in increasing soil organic matter and available soil P then rice straw. The application of organic matter resulted in the increase in total organic N in the soil. Such effect was greater in compost application than in rice straw application. In organic N, greatest was amino acid-N, followed by unidentifiable organic N. The least was amino sugar-N. The application of organic matter with and without nitrogen fertilizer affected the in organic fractions of P, particularly Fe-P and Al-P. The application of rice straw tended to increase Ca-P.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.25-31
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• 1986

This study was conducted to determine the effects of 5 years continuous application of compost and rice straw with the different rates of nitrogen fertilizer on physico-chemical properties of paddy soils and yield of rice. The results obtained were as follows; 1. The yield of rice was 7 and 4% higher at straw and compost treatment compared to the non-application of organic matter. The rate of yield response for nitrogen fertilizer was lowered as the amount of nitrogen application increased under the condition of organic matter application. 2. Dry mayer weight and total nitrogen content of rice plants were increased in the order of straw > compost > non-application of organic matter. Above two factors were positive correlations with yield but total nitrogen content was negative correlation with ripening rate. 3. $NH_4-N$ in the soil was higher at plot applicated with compost and straw than non-application. It was positive correlation ($r=0.62^*-0.79^{**}$) with total nitrogen content in rice plants from 15 days after transplanting to heading stage. 4. The physical properties of soil, hardness and infilteration rate, after 5 years experiment, were improved in the order of straw > compost > non-application of organic matter. Organic matter content in the soil was decreased 0.1% on the straw treatment after 4 years, 0.1% on the compost after 3 and 4 years, and 0.1% on the non-application every years.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.3
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• pp.39-49
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• 2020

Rice paddy cultivation is one of the major sources in methane (CH₄) emission of which accurate assessment would be a prerequisite for agricultural greenhouse gas management. Biomass treatment in paddy fields is an important factor that affects CH₄ emissions and thus needs to be taken into account. The objectives of this study were to apply drone images to investigate organic matter practices and to incorporate into the estimation of CH₄ emissions from paddy fields. Three study areas were selected by one from each of the three different regions of Yeongnam, Honam and Jungbu, which are the most active region in paddy cultivation. The eBee drone was used to take images of the study sites twice a year; Jul mid-season for identifying rice cultivation area; Jan for investigating rice straw management and winter crop cultivation. Based on biomass management practices, different emissions factors were assigned on an individual paddy field and CH₄ emmisions were estimated by multiplying respective areas. The ratios of rice straw application and winter crop cultivation were 1.4% and 37.2% in Hapcheon, 1.3% and 19.8% in Gimje, and 0.0% and 0.5% in Dangjin, respectively. The CH₄ emissions estimates for respective sites were 0.40 ton CH₄/year/ha, 0.34 ton CH₄/year/ha, and 0.29 ton CH₄/year/ha. On average, estimated CH₄ emissions of this study were 28.5% less than the current Tier 2 CH₄ emission estimation method.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.510-516
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• 2016

Soil respiration has been recognized as a key factor of the change of organic matter and fertility due to the carbon and nitrogen mineralization. In this study, we evaluated the effect of soil respiration on the light fraction-C and inorganic N content depending on temperature in soil applied with organic matter. Soil respiration was calculated by using total $CO_2$ flux released from soil applied with $2Mg\;ha^{-1}$ of rice straw compost and rye for 8 weeks incubation at 15, 25, $35^{\circ}C$ under incubation test. After incubation test, light fraction and inorganic N content were investigated. Rye application dramatically increased soil respiration with increasing temperature. $Q_{10}$ value of rye application was 1.69, which was higher 27% than that of rice straw compost application. Light-C and $NO_3-N$ contents were negatively correlated to soil respiration. Light-C in rye application more decreased than that in rice straw compost with temperature levels. These results indicate that temperature sensitivity of soil respiration could affect soil organic mater content and N availability in soil due to carbon availability. Also, light fraction would be useful indicator to evaluate decomposition rate of organic matter in soil under a short-term test.

• Applied Biological Chemistry
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• v.16 no.3
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• pp.128-136
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• 1973

An experiment was carried out to study the effects of Zn application on the rice plant of IR-667 and Jinheung varieties grown under the conditions of poor drainage and low available Zn. The results obtained were an follows; 1. The poor drained condition of the paddy field was more favorable for Zn utilization by the rice plants than the well drained condition. Also Zn application in the form of Zinc chloride $(ZnCl_2)$ seemed to significantly increased the rice yield of both IR-667 and Jinheung. 2. Zn content of IR-667 was much higher than that of Jinheung. The concentration of Zn in IR-667 rice plant treated by Zn fertilizer was about 200 ppm while that of control plot (not received Zn fertilizer) only 30 ppm. This result suggests that Zn application might improve the yield under the condition of poor drained soil when Zn concentration of IR-667 rice plant is around 30 ppm. 3. Absorption of Zn-65 by the rice plant was greater in the plants grown without Zn fertilizer than those with Zn fertilizer application, At harvest, the higher amount of Zn-65 was accumulated in the gram than in the straw. 4. Zn fertilization increased the grain yield in the soil of Paju, Dalsung, Chilg ok and Chungwon with low available Zn.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.4
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• pp.29-37
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• 2011

Effect of rice straw mat and wood shaves on the reduction of runoff and nonpoint source (NPS) pollution loads from field plots were experimentally studied. Three runoff plots of $5{\times}22$ m in size and 3 % in slope were prepared on a loamy sand field. Each plot was equipped with a flume to measure runoff and collect water samples. Experimental treatments of surface cover were bare, wood shaves (1,000 kg/ha) and rice straw mat cover (3,000 kg/ha). Under radish was cultivation. During the growing season of the radish, three rainfall-runoff events were monitored. Effect of wood shaves and straw mat cover on runoff reduction was 4~30 % and 33~75 % respectively compared to control. The effect on NPS pollution reduction was 36.8 and 64.3 % in BOD, 41.1 and 80.8 % in SS, 34.0 and 56.1 % in TP and 28.0 and 56.6 % in TN respectively. It was analyzed that the reduction of runoff and NPS pollution were mainly contributed by the decrease of rainfall energy impact and flow velocity and the increase of infiltration due to the surface cover materials. Rice straw mat showed very stable soil cover while large portion of wood shaves were lost during heavy storm events. It was concluded that straw mat was an efficient cover material to reduce NPS pollution from upland fields.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1108-1113
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• 2012

The changes of soil organic carbon (SOC) content in paddy soils (sandy loam) were assessed from data of the 59 years fertilization plots in which the continuous rice cropping experiment started in 1954. The treatments were no fertilization(no fert.), NPK fertilization (N, NPK), NPK plus rice straw compost (NPK+C), and NPK plus rice straw compost, silicate fertilizer and lime (NPK+CLS). After 41 years, SOC content in NPK+C and NPK+CLS treatment in surface soils (0~15 cm) reached at the highest, followed by maintaining a plateau level for 8 years. After 51 years, they showed a tendency to decrease. Peak concentrations of soil organic carbon were $20.1g\;kg^{-1}$ in NPK+CLS, $19.1g\;kg^{-1}$ in NPK+C, $13.3g\;kg^{-1}$ in NPK, $11.9g\;kg^{-1}$ in N, and $11.6g\;kg^{-1}$ in control. Dissolved organic carbon(DOC) contents in surface soil solution were about 2.3 times higher in NPK+C than that in NPK+CLS. Therefore, SOC in subsurface soil(15~30 cm) was greater in NPK+C than the other treatments. These results indicate that continuous application of rice straw compost and silicate fertilizer affected significantly on the level of SOC in surface soils, subsurface soils, and soil solutions. Thus, the combined applications of NPK fertilizers with organic compost and silicate as a soil amendment are recommended as the best fertilization practice for soil carbon accumulation, environment conservation, and enhancement of soil fertility status in the continuous rice cropping system.