• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.49-59
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• 2019

The field trial was performed to evaluate the rice growth and yield in different direct seeding methods after Italian Ryegrass Harvest The required time for seed emergence was for 7 ~ 8days in the tested direct seeding methods and there was high in seedling establishment in order of wet hill-seeding with iron-coated seeds > water seeding with iron-coated seeds > wet hill-seeding with soil coverage with pregerminated seeds. The rice plant height was shorter in the tested direct seeding methods than that of machine transplanting until 45day after seeding but there was not significant difference in terms of statistical analysis at 63day after seeding. The growth of tiller number in the rice plant was high in water seeding with iron-coated seeds and wet hill-seeding with soil coverage and low in wet hill-seeding with iron-coated seeds compared to machine transplanting. The yield component in the tested direct seeding methods was not significant difference in terms of statistical analysis. The milled rice yield in the tested direct seeding methods was higher 2 ~ 8% being with 4.94 ~ 5.24t/ha than that of machine transplanting but there was not significant difference in terms of statistical analysis. The percentage of head rice was low in the tested direct seeding methods compared to machine transplanting. The weedy rice was not occurred in the tested rice cultivation methods. In conclusion the direct seeding method would be recommended to be a suitable to in following by Italian ryegrass harvesting in southern area of Korea in terms of reduction in production cost and high income basis for rice growing farmers.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.4
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• pp.398-410
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• 1982

Summer crops grown in uplands are greatly diversified and show a large variation in difference with year and location in Korea. The principal factor for the variation is weather, in which precipitation and temperature play a leading role and such a weather factors as wind, sun lights also influence production of the summer crops. Since artificial control of weather conditions as a main stress factor for crop production is almost impossible, it must be minimized only by an improvement of cultivation techniques and crop improvement. Precipitation plays a role as one of the most important factor for production of the summer crops and it is considered in two aspects, drought and excess moisture. This country, which belongs to monsoon territory, necessarily encounter one of this stress almost every year, even though the level is different. Therefore, the facilities for both drought and excess moisture are required, but actually it is not easy to complete for them. On this account, crops tolerant to drought, excess moisture and pests should be considered for establishing summer crops. For the districts damaged habitually every season, adequate crops should be cultured and appropriate method of planting, drainage and weed control should be applied diversely. Injuries by temperature is mainly attributed to lower temperature particularly in late fall and early spring, although higher temperature often causes some damages depending upon the kind of crops. Sometimes, lower temperature in summer season playa critical role for yield reduction in the summer crops. However, certain crops are prevented to some extent from this kind of stress by improving varieties tolerant to cold, hot weather or early maturing varieties. As is often the case, control of planting time or harvesting is able to be a good management for escaping the stress. Lodging, plant diseases and pests are considered as a direct or indirect damage due to weather stress, but these are characters able to be overcome by means of crop improvement and also controlled by other suitable methods. In addition, polytical supports capable of improving constitution of agriculture into modern industry is urgently required by programming of data for the damages, establishment of damage forecasting and compensation system.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.3
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• pp.264-271
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• 1988

This experiment was carried out to investigate the effects of long-term applications of organic matters on the chemical properties and on the application levels of nitrogen in Fluvio-Alluvial plain of Jeonbug series. The amounts of application of rice straw and compost, the sources of organic matters, were 500 and 1,000 kg/10a in combined with the different nitrogen levels of 0.15 and 20 kg/10a, respectively. The results obtained from the 9 year's experiment during 1979 to 1987 were summarized as follows: I. In long-term application of Organic matter the soil pH showed the lowest value in the 3rd-4th year at rice straw and 5th-6th year at compost but it varied less in control plot for 9 years. 2. Organic matter content in the soils was gradually increased by yearly application of organic matter, while it was higher in rice straw than in compost since the 5th year. 3. The contents of available silica and available phosphate in soil were rapidly increased by long-term application of organic matter and it was especially higher in rice straw than compost, but it was gradually decreased in control plot. 4. The contents of exchangable cations (Ca, Mg and K) and the total nitrogen were increased by long-term application of organic matter they were in rice straw than in compost. But they showed decreasing tendency in control plot. 5. The soil Eh was lower in order of rice straw, compost and control plot however application of orgnic matter resulted in increasing soil Eh due to the rapid reduction of soil from panicle formation to heading stage in rice cultivation. 6. The number of panicles per $m^2$ and the number of granis per panicle were increased by increment of nitrogen levels in all treatments and especially largest in rice straw application. But 1,000 grain weight increased in low nitrogen level with long-term applications of organic matter. 7. It was estimated that the application levels of nitrogen by long-term application of organic matter were 21, 24 and 20 kg/10a for 1st-3rd, 4th-6th and 7th-9th year in rice straw application, and 16 and 19 kg/10a for 1st-3rd and 4th-9th year in compost application, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.1
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• pp.31-42
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• 1999

To investigate the effects of the composts made of sewage sludges on the physico-chemical properties of soil and growth of paddy rice, the variations of chemical properties in soil, the contents of inorganic matters and heavy metals in plant tissues, the contents of heavy metals in brown rice, the growth response of paddy rice and grain yield were investigated. The results were summarized as follows : The contents of organic matters, N, available $P_2O_5$ and exchangeable K in soil were increased by application of the composts. The contents of N and available $P_2O_5$ in soil were remarkably decreased at the harvesting time in comparing with the 20th day after application of the composts. The contents of heavy metals in soil were increased very slightly by application of the com-post. At the harvesting time, the contents of N and K were not varied in all plant tissues at the plot of the compost in comparing with the plot of the NPK. The content of $P_2O_5$ in plant was increased by application of the composts. The contents of heavy metals in plant tissues and brown rice were not changed among the treatments. When the composts were applied to the pot at the rates of 1,000, 2,000, 4,000 and 6,000kg/10a with NPK, the numbers of grain yield were increased with 3, 18, 44 and 54% in comparing with NPK plot, respectively. Dry weight, the numbers of tillers and spikelet of the rice plant were increased by application of the composts.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.3-7
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• 1996

Effects of the nitrogen application time and amounts on the nitroger. uptake and recovery of fertilizer nitrogen applied at panicle formation stage was investigated in connection with the growth and yield of rice drill-seeded in puddle-soil. silt loam of Jeonbuk series. Urea was applied as nitrogen source. Nitrogen uptake and recovery of fertilizer nitrogen by rice plant was highest in the treatment applied nitrogen at 20 days before heading. Culm length, internode length (4th and 5th) and lodging index were increased by earlier application time and higher level of nitrogen. but filled grain ratio and 1,000 grain weight showed the opposite trend Panicle number per square meter and grain number per panicle was significantly decreased in nitrogen application at 10 days before heading. Rice yield was the highest in 33kgN/ha(conventional amount at 20days before heading, and yield in 26kgN/ha(80% of conventional amount) at 20 days before heading and in 33kg/ha at 15days before heading were nearly the same as conventional treatment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.12
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• pp.31-36
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• 1972

These studies were carried out to find out the proper plant spacing and the optimum amount of nitrogen for maximum yield, on the occasion of early planting with creen vegetable (soybean for cook with rice) at the low temperature in early spring. The plant spacing were applied in 5 levels (50cm$\times$5cm, 50cm$\times$10cm, 40cm$\times$10cm, 30cm$\times$10cm and 30cm$\times$20cm) and the amount of nitrogen were applied in 4 levels (non, standard, twice and triple-amount), The triple super phosphate and potassium chloride were applied only in standard amount. The promotion of flowering was practised by the short-day treatment for 10 days (11 hr. a day). The variety examined was the early maturing one, HOKKAI # 1. and the results are as follow. 1. The plant spacing for maximum yield by the promotion of branch, pod and garin per a plant recognized the fact that there were 2 levels (50cm$\times$10cm and 30cm$\times$20cm planting method) and the maximum yield by the promotion of pod and grain per area showed the fact that there were 2 levels (50cm$\times$5cm and 30cm$\times$10cm planting method) in narrow planting method. 2. The optimum amount of nitrogen applied for maximum yield of pod and grain per area recognized w hat was sufficient as standard amount.

• Korean Journal of Weed Science
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• v.9 no.3
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• pp.221-229
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• 1989

This study is conducted to evaluate the effect of KIM-112 (Ca-3, 5-diode-4-propyonly-cyclohexane-1-carboxylate) application at 13, 8 and 3 days before heading for the possibility of lodging prevention, growing pattern of several organisms, growth and yield in paddy rice. KIM-112 was the most effective in reducing elongation of the third internode when it was applied at 13 days before heading(13DBH) and the second internode when it was applied at 8DBH and 3. KIM-112 gradually inhibited internode elongation of rice with increase in dosage starting from 1.0ga.i./10a. The culm length shortened by 7-17% at 3DBH. The maximum distribution of leaf blade at canopy structure was positioned higher on KIM-112 application than on untreated. Lodging index decreased by 8-47% on KIM-112 application and field lodging degree(0-5) was 5 at untreated but KIM-112 application was only 1.3-2.0 of 3 DBH and was little lodging of 8-13 DBH. Ripened grain ratio of KIM-112 application were higher than those of untreated. Yield increased by 27-37% at KIM-112 application.

• Applied Biological Chemistry
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• v.14 no.3
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• pp.183-189
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• 1971

The studies reported herein were conducted to inquire the effect of fused siliceous materials which mixed with sand and quartz added calcium fertilzer on rice grown on low available silica content soil. The applied nitrogen level were examined for the two plots, nitrogen 10kg and 20kg per 10 a., and the siliceous materials(Wollastonite, Fused sand and Fused quartz) were applied as levels to 100kg, 300kg and 500kg per 10a. in the pots. The results are summerized as follows; 1. The available silica content solved in N/2 HCl solution of fused sand was more than of fused quartz but the silica solubility in 2% citric acid of fused quartz were higher than other. 2. The absorbed silica content by plant grown on the fused quartz plot was the highest among other siliceous materials and of fused sand and natural wollastonite were at almost equal. The ratio of absorbed silica of natural wollastonite was highest among them and in fused materials, the quartz was higher than sand. 3. The productivity of rice was increased by percentage of filled grain, weights of 1000 grains, and number of spikelets on account of the large quantity of the silica absorbed by plant Especially fused quartz showed the highest productive effect among siliceous materials and natural wollastonite and fused sand were similar effect. 4. From the above results. the fused quartz was selected as expelled siliceous fertilizer on rice plant among them and the fused sand was equal effect to natural wollastonite.

• Korean Journal of Weed Science
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• v.13 no.1
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• pp.19-25
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• 1993

This study was conducted to evaluate effect of trinexapac-ethyl{4-(cyclopropyl-${\alpha}$-hydroxy-methylene)-3, 5-dioxocyclohexan carboxylic acid ethyl-ester} for lodging prevention, growth pattern of several organs and yield in machine transplanted rice with 10-day-old seedling. Elongation rate of the second internode affected the most largely by trinexapac-ethyl was 33-52, 35-56 and 42-53% of check in application of 12, 7 and 5days before heading, respectively and, culm elongation was reduced 27-34, 20-29 and 20-25% in application of the same time. Lodging in field was decreased by treatment of trinexapac-ethyl compared with check, Ripened grain ratio and yield were increased about 3-7 and 7-17% by trinexapac-ethyl, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.123-129
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• 1987

In order to find out more effective countermeasures against growth damage of paddy rice due to the irrigation of livestock waste water, pot experiments were carried out in 1985 and 1986. Experiment I conducted in 1985 was to find out the effects of irrigation control and application of ameliorators to paddy soil with irrigation of animal waste water. Experiment II conducted in 1986 was to find out the amounts of wollastonite to be applied. The results obtained were as follows. Experiment I ; Rice yields were higher in the treatment of continuously submersion until harvest than in that of intermittent irrigation. The yield was also increased with the application of soil ameliorators and it showed higher increase in the treatment of zeolite and wollastonite. Nitrogen contents in plant were increased with the nitrogen application and more amounts of irrigation of waste water, but they were considerably decreased with the application of soil ameliorators. Experiment II ; Rice yields were increased with the application of wollastonite and the optimum level of wollastonite for maximum yield in condition of 3.0 g/pot of nitrogen application was belived to be 60g/pot. The increment of yield by the application of wollastinte was though to be due to increase of No. of grains per panicle and ripening ratio. Steriled neck occurred by rice disease such as rice blast was increased with increasing the amounts of nitrogen application and nitrogen contained in irrigated waste water but that was remarkably decreased with the application of wollastonite.