• Korean Journal of Organic Agriculture
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• v.24 no.2
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• pp.221-234
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• 2016

The application of animal manure on farm fields is one of the most economical ways. However, the continuous application of manure in paddy fields might change soil properties influencing the growth of rice plant. Thus, this study was conducted to investigate the changes in selected chemical and biological properties of soils and rice production as affected by the applications of two different fertilizer sources, which were the consecutive applications of liquid swine manure (LSM) and chemical fertilizer (CF), during the three experimental years, from 2012 to 2014. Application amount of LSM was based on 100% of nitrogen fertilizer recommendation rate for rice cultivation estimated by soil testing. Plant height and tiller number in rice at the first year of liquid swine manure manure plot were lower than those of chemical fertilizer plot. Height and tillers of rice in liquid swine manure plot were higher than those of rice in chemical fertilizer plot after consecutive application for 3 years. Rice yield In the first year of application was decreased by 7% than that of chemical fertilizer, but the yield of rice in the third year of application in LM 100% plot was increased by 8% compared to the chemical fertilizer. Toyo-taste value of milled rice in LM 100% was decreased by increasing of protein contents and decreasing rate of perfect grain. The K and Zn contents in the soil were increased in the plots of consecutive LSM application. The results implied that the liquid manure may neither decrease the yield of rice and nor increase soil properties except K and Zn in the soil, and decrease rice quality.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.4
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• pp.325-332
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• 1983

To investigate interactions of silicate and phosphate applied in paddy soil, different levels of the two fertilizers were treated on pots of Jinheung variety of Japonica rice, then availability and absorption of the silicate and phosphate and growth of the rice plant were analyzed. The availability of silicate applied in soil was reduced by increased application of phosphate and this antagonism implied the interaction of silicate and phosphate in soil. The silicate absorption by rice plants was remarkably reduced by the phosphate application, while the phosphate absorption was reduce only at high levels of silicate. At low levels of silicate, the phosphate absorption was affected differently depending on growth stage or parts of the rice plant. The application of silicate fertilizers increased the pH of the soils. The application of silicate and phosphate fertilizers improved the plant height, the tiller number, and the grain weight, but not the dry weight of the grain. The effect of interaction of silicate and phosphate on the plant growth did not appeared.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.14
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• pp.41-45
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• 1973

This study was carried out in the central part of Korea in 1972 to investigate optimum grain number per square meter and variation of the yield and its components in the direct sowing culture on irrigated paddy field. The results could be summarized as follows; 1. Number of maximum tillerings was directly increased with increase of grain number from 120 to 280 per square meter and it was gradually decreased with increase of number sowing grain. So number of maximum tillerings showed at the plot of 280 grain per square meter. Also it was showed remarkable competition at the plot more than 280 grain per square meter. 2. Percentage of effective tiller was decreased with increase of number of sowing grain from 120 to 280 per square meter and after it was gradually decreased with increase of number of sowing grain. 3. It was not remarkable competition in plot less than 1, 000 tillering per square meter on the number of maximum tillerings. 4. It was remarkable positive correlation between the number of panicle and the number of sowing grain, but it was tendency to negative correlation between the number of panicle and the number of spiklets per panicle, and between the number of panicle and the ripening ratio. 5. Correlation coefficient between the yield and the number of spiklet per square meter of land area was 0.929, r=0.695 in the yield and the number of panicle, r=0.796 in the number of panicles and the number of spiklets per square meter Also in rank correlation, it was showed most highly positive correlation(r=0.954) between the yield and the number of panicles, so number of panicles was most largely dominated on yield among the yield components in direct sowing culture on irrigated paddy field. 6. It was producted highest yield in the plot of 280 grain sowing per square meter.

• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.79-84
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• 1998

This study was conducted to obtain information on occurrance ecology of Aneilema keisak Hassk. and establish its effective control system in direct-seeded rice. Optimum germination temperature and storage temperature to break dormancy were $22^{\circ}C$ and $4^{\circ}C$, respectively. Optimum content of soil moisture for germination was 35%(w/w) in clay loam soil, where recorded 85% of germination rate. In the inter-specific competition between density of Aneilema keisak Hassk. and constant rice-mixed stands, the plant height and the tiller of rice were decreased with increase of density of Aneilema keisak Hassk. Among the herbicides tested, piperophos+dimethametryn(8.2+2.2 g ai/10a) GR and. pyrazosulfuron-ethyl+mefenacet(2.1 + 105 g ai/10g) GR were found to be effective for control of Aneilema keisak Hassk., having more herbicidal effect with an earlier application.

• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.631-642
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• 2012

This study was carried out to determine the effect of SCB compost leachate on the growth and yield of rice. Field experiment was conducted on sandy loam soil under the different fertilizer management; 80%, 100%, 130% N level of SCB leachate based on 13kg N/10a of conventional farmer application level and chemical fertilizer as control. The plant height and tiller's number of 80 and 100% N levels of SCB leachate were lower than that of the chemical fertilizer plot. But in the plot of 130% N level of SCB leachate the plant height and tillers was higher than that of chemical fertilizer. And the SPAD reading value of leaf in plot of 130% N level was higher than that of the chemical fertilizer. Rice yield in the 80% and 100% SCB leachate was increased from 12 to 13% that of plot of chemical fertilizer. But rice yield of 130% N-level was decreased 7% compared with chemical fertilizer. Rice quality of the application levels of 80 and 100% SCB leachate levels was significantly better than those of chemical fertilizer and 130% level of SCB leachate. In conclusion, the 100% N application of SCB leachate was improved yield and quality of rice.

• Korean Journal of Weed Science
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• v.10 no.4
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• pp.248-254
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• 1990

Initial crop injury, plant growth and yield of machine-transplanted rice of seedlings different in plant age (8-, 20-, and 35-day-old seedlings) after application of herbicides were investigated in field. The herbicides employed were butachlor, dithiopyr, pyrazolate(applied only for 8-day-old seedling), dithiopyr+pyrazolate, dithiopyr+ bensulfuron methyl), and butachlor+bensulfuron methyl(applied only for 20-and 35-day-old seedlings). There was no significant difference in plant growth, yield components and yield between the different-aged seedlings of the untreated check, except for the heading date, The heading date of 8-day-old seedling was delayed for 2 and 6 days as compared with those of 20-and 35-day-old seedlings, respectively. A very slight initial crop injury was found with the tested herbicides for all the different-aged seedlings. No significant differences in plant height and tiller number occurred between different-aged seedlings and the respective untreated check. All the herbicides used gave a good weeding effect. Yield components and yields were not affected by different-aged seedlings after application of the herbicides.

• Korean Journal of Weed Science
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• v.16 no.4
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• pp.301-308
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• 1996

In this study, a propagation characteristics of green kyllinga(Kyllinga brevifolia var. leiolepsis H.) was investigated. Two to three rhizomes(1st rhizome) arised from the basal part of main shoot at 4th leaf stage and were grown to extend on the soil surface. Then new shoots(lst tillers) emerged from every node of the 1st rhizome. Second rhizomes also arised from the basal part of lst tiller at the time of 4th leaf openning. With such a regularity, 5th rhizomes and about 688 shoots were produced from one plant during one year-cultivation without competition under the natural condition. The degree of vegetative growth and seed formation was 3 times and 2.5 times higher in rhizomeoriginated plant than in that from seed, respectively. The amount of seed formation and the 1000 seeds weight was highest in one planted on June 1 and Aug. 1, respectively. Short-day treatment of less than 14hr appeared to be necessary for the induction of flowering and it was effective as treated not during germination but since at least 2 leaf stage of green kyllinga. Each shoot individually responded to short-day. When plants were exposed to short-day (9hr, day / 15hr, night) treatment at the stage of 2-3 leaves, more than 7 cycles were required for flowering induction. Bolting in main shoot occurred after emergence of 4 leaves under the short-day condition. Exogenous $GA_3$ slightly accelerated the velocity of bolting only in short-day condition.

• Korean Journal of Weed Science
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• v.30 no.3
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• pp.258-265
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• 2010

The effects of organic-compound fertilizer on weed control and rice growth in the transplanting rice cultivation were researched in this article. The results showed that the growth of transplanted rice was promoted (the increased rate was 10.3~27.2%), but the plant number for Echinochloa crus-galli was controlled (the inhibition rate was 50.3~89.2%), besides, small amount of organic-compound fertilizer in controlling Aneilema keisak was highly effective when the transplanted rice was treated with 125~250 kg $10a^{-1}$ organic-compound fertilizer. Moreover, E. crus-galli, Monochoria vaginalis and A. keisak were inhibited largely by increasing the water depth (1~5 cm), whereas Eleocharis kuroguwai and other sedges weeds were not effected by water depth. Compared with the temperature of $20{\sim}35^{\circ}C$, the plant occurrence of E. crus-galli and M. vaginalis at high temperature was inhibited (the inhibition rate were 75.4~92.2% and 49.5%~81.6%, respectively). When the transplanted rice was treated with the above organic-compound fertilizer after 10day, the inhibition rate of plant occurrence for E. crus-galli and M. vaginalis was 33.7% and 23.3%, respectively. Similarly, in the later period of rice growth, the plant height and the numbers of tiller grew slowly in conventional soil in comparison with the soil treated with organic-compound fertilizer. It has been found that the rice yield in experimental soil was decreased by 4%. This result in the field experiment showed that organic material contents in conventional soil were lower than that in soil which used the organic-compound fertilizer. Weed control in experimental soil showed 60.5% lower effects than that in conventional soil.

• Korean Journal of Remote Sensing
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• v.32 no.5
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• pp.483-497
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• 2016

Unmanned Aerial Vehicle (UAV) imagery are being assessed for analyzing within field spatial variability for agricultural precision management, because UAV imagery may be acquired quickly during critical periods of rapid crop growth. This study refers to the derivation of barley and wheat growth prediction equation by using UAV derived vegetation index. UAV imagery was taken on the test plots six times from late February to late June during the barley and wheat growing season. The field spectral reflectance during growing period for the 5 variety (Keunal-bori, Huinchalssal-bori, Saechalssal-bori, Keumkang and Jopum) were measured using ground spectroradiometer and three growth parameters, including plant height, shoot dry weight and number of tiller were investigated for each ground survey. Among the 6 Vegetation Indices (VI), the RVI, NDVI, NGRDI and GLI between measured and image derived showed high relationship with the coefficient of determination respectively. Using the field investigation data, the vegetation indices regression curves were derived, and the growth parameters were tried to compare with the VIs value.

• Korean Journal of Weed Science
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• v.9 no.2
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• pp.141-148
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• 1989

Echinochloa species collected from 13 places of Korea appeared to be morphologically very different. They were classified by Yabuno's seed morphology method into two species such as Echinochloa oryzicola and Echinochloa crus-galli which have two varieties such E. crus-galli var, cuss-galli and var, praticola. Among them, E. oryzicola was morphologically similar to Oryza sativa, but it had small leaf length with straight from, no awn, late heading and little interspecific variance. As compared with E. oryzicola, E. eras-galli var. crus-galli, and var, praticola showed a great variance exerting so difficulty in classifing them morphologically, particularly a great variance in leaf length, tiller number and grain size. E. oryzicola species showed the more sensitive response to butachor and thiobencarb herbicides than E. eras-galli var. praticola and var. eras-galli. However, E. eras-galli var. praticola was themore sensitive one to pretilachloa herbicide than such as E. oryzicola and E. eras-galli var. eras-galli, indicating that Echinochloa species might have a selective response to the annual herbicides tested.