• Korean Journal of Environmental Agriculture
• /
• v.19 no.5
• /
• pp.433-441
• /
• 2000

A feasibility study was performed to examine the agronomic application of treated sewage on paddy rice culture by field experiment for two consecutive years. The domestic sewage was treated by the constructed wetland system which was in subsurface flow type and consisted of sand and macrophyte. The effluent of the wetland system was used for irrigation water. The effluent was diluted to maintain the total nitrogen concentration below $26mg{\cdot}L^{-1}$ in the first year and used without dilution in the second year experiment. Growth components and yields were compared against the CONTROL plot where conventional method was applied. And also, soil characteristics of the plots before and after reclaimed sewage irrigation were analyzed. Generally, addition of the treated sewage to the irrigation water showed no adverse effects on paddy rice culture, and even enhancement was noticed in both growth and yield. Irrigation of treated sewage after concentration adjusted with conventional fertilization showed the better result, and the yield exceeded that of CONTROL case where clean water was irrigated. Soil characteristics changed after irrigation, and significant EC increasing was observed for the reclaimed sewage irrigation plots. From this study, it appears that reuse of treated sewage, as supplemental irrigation water could be a feasible and practical alternative. For full-scale application, further study is recommended on the specific guideline of major water quality components in treated sewage for irrigation and public health.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.1
• /
• pp.61-67
• /
• 1997

This experiment was carried out from 1979 till 1983 to elucidate the underdrainage effect on soil salinity and growth of rice plastic underdrainage was established 5m and 8m intervals in April of 1979 and Jinjubyeo the medium maturing rice variety was transplanted by hand at late of May. The results are as follow; The desalination effect was higher in 5m interval underdrainage than 8m interval underdrainage and the salt content was lower than 0.3％ at 1 year after in 5m interval, 2 years after in 8m interval underdrainage and 3 years after at control. Farther the distance from underdrainage position, less the desalinization rate that desalinization was least at center part of the underdrainage position. Desalinization effect was highest 30cm of soil depth and decreased deeper than it. Shorter the underdrainage interval, more the panicle number, heavier 1, 000 grain weight and higher the milled rice yield. But the milled rice yield wasn't significantly different between the underdrainage interval from 3 years after underdrainage.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.4 no.1
• /
• pp.81-91
• /
• 1968

To investigate the effects of foliage clipping time, degree, and nitrogen top-dressing after clipping on the growth and the agronomic characteristics, rice plants grown under ordinary cultural practices were clipped at the maximum tiller stage, 10 days prior to, and after that stage, respectively, with varying clipping, height, as 0, 1/3, 1/2, and 2/3 of plant height. And nitrogen was top-dressed at the rate of 0, 2, 4, 6 kg per 10 are immediately after clipping. The variety used was ＂Jinheung＂. The results obtained are outlined as follows: 1. Effect of clipping on the growth of rice plant: The subsequent growth was quite rapid during 10 days after clipping, and resulted, on the whole, in nearly complete recovery of defoliation by 20 days after clipping. a) Generally, the later the clipping time, the more growth accelerated. Rice plants clipped before the differentiation of ear primordia nearly recovered the damage, and in certain cases exceeded non-clipped plants in height. But the height of the rice plant clipped after the differentiation of ear primordia was somewhat smaller than that of non-clipped. b) Growth rate was rather rapid in the case of severe cutting, and the height of slightly clipped plants was taller than that of non-clipped plants. However, rice plants clipped to the extent of 2/3 of plant height did not fully recover the damage of defoliation compared to non-clipped plants. c) Nitrogen dressing was effective to rapid recovery of defoliation, the effect increasing with the increasing amount of application. d) Ear-heading was delayed in clipped plots, and this tendency was more apparent with later clipping time, more severe clipping, and increased amounts of nitrogen application after cutting. The range was 6 days at maximum. 2. Effect of defoliation on the yield and its components of rice plants: The yield response to clipping varied somewhat with its time, degree, and nitrogen application after cutting: yield increase of about 10% and decreasement of about 25% at maximum compared to the control plot. Grain yield of most plots was decreased. a) Clipping before the differentiation of ear primordia did not much affect the agronomic characteristics of rice plants. However, clipping after that growth stage decreased culm length, number of panicles, number of spikelets per panicle, and maturing rate of grain to some extent. Consequently this treatment resulted in decrease of about 10% in grain and straw production in spite of increase in panicle length and effective tillering rate. b) Slight, clipping decreased number of spikelets per panicle a little, and the yield of grain and straw by 4-5%, although effective tillering rate was somewhat increased. With severe clipping, panicle kngth, number of panicles, and number of spikelets per panicle decreased more, and the yield of grain and straw decreased about 10%. c) Nitrogen dressing after clipping at the rate of 2 kg per 10 are was effective in increasing grain yield. Nitrogen application over the rate of 4 kg per 10 are increased culm length, number of spikelets per panicle, and straw production, but this decreased the maturing rate, and the 1, 000-grains weight to some extent and resulted in decrease of grain yield.

• Plant Resources
• /
• v.3 no.3
• /
• pp.226-232
• /
• 2000

The availability of enokitake cultural waste for Lentinus edodes cultivation was investigated, although hardwood sawdust has traditionally been used as a substrate for this fungus. Firstly, physiochemical characteristics of cultural waste were analysed. Secondly, mycelial growth characteristics and fruiting yields of L. edodes on waste treated in some methods were determined. Physiochemical characteristics of enokitake cultural waste showed that the millwaste complex was a little degraded by enokitake fungus and suggested the probability that most component lost by enokitake could be rice bran. Mycelia of L. edodes grew and fruited well on waste supplemented by fresh rice bran and Quercus sawdust although didn't on waste only. Mycelial growths of these fungi on waste were accelerated when supplemented by rice bran to the percent of 40(w/w) but decreased or suppressed at above ratios(30, 40%, w/w). Supplementations of oak sawdust at above 40%(w/w) of the waste and rice bran at 20%(w/w) of the sawdust allowed such a good mycelial growth as to be selected as a pertinent mixing ratio for fruiting medium. A fruiting yield on enokitake cultural waste supplemented by oak sawdust (at 40% of the waste, w/w) and rice bran (at 20% of the sawdust, w/w) was not inferior to that on oak sawdust supplemented by rice bran only (at 20% of the sawdust, w/w). These results indicated strongly the potentiality of enokitake cultural waste as raw materials for shiitake cultivating substrates.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.22 no.2
• /
• pp.37-41
• /
• 1977

Zeolite was applied of the tidal land and its effect on growth and yield of the two rice varieties, Yushin and Jinheung, was studied. The salinity of the zeolite treated soil was lower than that of the control. The effect of zeolite on growth of rice was appeared at the maximum tillering stage. The remarkable effect of zeolite on grain yield appeared in the variety Yushin, an indiea type. The amount of 600kg/10a was recognized to be an optimum amountd of the zeolite application in the tidal land.

• Korean Journal of Agricultural Science
• /
• v.46 no.4
• /
• pp.791-798
• /
• 2019

This experiment was conducted to find out the difference between roughage productivity and feed value by using two domestic forage rice cultivars in a mid-west reclaimed rice field in Korea. During the growing period, Na⁺ content in soil showed no significant difference between the two cultivars; however, the K⁺ content in the soil was significantly lower than that in which the Mogwo was grown. The tiller number was 45.5 to 58.8, which was higher than that of Mogyeong, and the leaf number was higher than that of Mogyeong. The dry matter yield per 10 a was 1,338 kg for Moggyang and 1,532 kg for Mogwoo. At the harvest time, the crude protein yield per 10 a produced 108 kg of Mogyang and 170 kg of Mogwoo, and the total digestion nutrient (TDN) yield per 10 a also produced about 617 kg of Mogyang and 880 kg of Mogwoo. To sum up the above results, Mogwo, which has many tiller numbers and leaf numbers, has a high dry matter production, a relatively low neutral detergent fiber (NDF) and acidic detergent fiber (ADF), and a high crude protein yield and TDN yield, and it was better when cultivating the forage rice cultivars in reclaimed land.

• Korean Journal of Organic Agriculture
• /
• v.19 no.3
• /
• pp.397-404
• /
• 2011

This experiment was performed to study growth and yield of rice (cv. Dongjinbyeo) and soil properties affected by the application of rice straw, compost, and hairy vetch. An application of rice straw and compost led to the decrease in plant heights and tillers compared with chemical fertilizer whereas hairy vetch application resulted in slight increase. Panicle no per plant was the highest in chemical fertilizer and there was no difference among organic matters. Grain per panicle was no difference among chemical fertilizer, rice straw, and compost whereas was the lowest in hairy vetch application. The 1,000 grain weights did not show any statistic difference and the ripened rate was enhanced in all treatments of organic sources compared with chemical fertilizer. Therefore, an index of rice yield of compost, rice straw, and hairy vetch to chemical fertilizer (100%) was 77, 72, and 103%, respectively. In addition, an application of organic sources led to the increase of soil pore space and this contributed to the improvement of soil physical property.

• Korean Journal of Environmental Agriculture
• /
• v.18 no.3
• /
• pp.229-235
• /
• 1999

To identify the differences on plant growth and yield of two rice cultivars among direct water-seeding methods broadcasting on flooded paddy surface(BF), drilling on flooded paddy surface(DF), and puddled-soil drill seeding(PD) under markedly different weather condition between 1995 and 1996. The mean air temperature for duration from May to June, early growth stage of rice in 1995 was lower $1{\sim}3^{\circ}C$ than that in normal or 1996. In 1995 the respiratory consumption index during panicle formation stage and early ripening stage was higher than those of in 1996 or normal year. Number of seedling stand among the methods of direct seeding rice appeared slightly higher in order of BF>DF>PD. Properly in Nonganbyeo, the number of seedling stand was much low in 1995 compared with in 1996. The leaf area index and shoot dry weight at early growth stage of rice plant and culm length at mature in 1995 were larger in direct water seeding rice than those of machanical transplanting rice, but in 1996. Faster ripening speed and shorter ripening period of rice crop appeared in 1996 compared to in 1995. It was due to higher growing degree-days, sunshine hours and solar radiation during rice growing season in 1996. Dongjinbyeo rice showed higher yield than Nonganbyeo which had lower ripened grains especially in 1995.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.59 no.4
• /
• pp.27-42
• /
• 2017

The global rise in atmospheric $CO_2$ concentration and its associated climate change have significant effects on agricultural productivity and hydrological cycle. For food security and agricultural water resources planning, it is critical to investigate the impact of climate change on changes in agricultural productivity and water consumption. APEX-Paddy model, which is the modified version of APEX (Agricultural Policy/Environmental eXtender) model for paddy ecosystem, was used to evaluate rice productivity and evapotranspiration based on climate change scenario. Two study areas (Gimjae, Icheon) were selected and the input dataset was obtained from the literature. RCP (Representitive Concentration Pathways) based climate change scenarios were provided by KMA (Korean Meteorological Administration). Rice yield data from 1997 to 2015 were used to validate APEX-Paddy model. The effects of climate change were evaluated at a 30-year interval, such as the 1990s (historical, 1976~2005), the 2025s (2011~2040), the 2055s (2041~2070), and the 2085s (2071~2100). Climate change scenarios showed that the overall evapotranspiration in the 2085s reduced from 10.5 % to 16.3 %. The evaporations were reduced from 15.6 % to 21.7 % due to shortend growth period, the transpirations were reduced from 0.0% to 24.2 % due to increased $CO_2$ concentration and shortend growth period. In case of rice yield, in the 2085s were reduced from 6.0% to 25.0 % compared with the ones in the 1990s. The findings of this study would play a significant role as the basics for evaluating the vulnerability of paddy rice productivity and water management plan against climate change.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.266-266
• /
• 2017

In recent years, adoption of the System of Rice Intensification (SRI) is spreading in most Asian countries, and more recently in Cambodia is one of the Asian countries with high adoptions of SRI. We conducted on-farm experiment to investigate the effects of SRI on rice growth and yield in the farmers' fields in rainfed region of southern Cambodia. The study was undertaken in rainfed lowland fields of Popel commune ($11^{\circ}$ 04' 67" N, $104^{\circ}$ 40' 79" E) of Tram Kak District in Takeo Province during the wet seasons in 2012, 2013, and 2015. A total of 32 on-farm experiments were conducted during the wet seasons for three years of 2012 (11 fields), 2013 (8 fields), and 2015 (13 fields). Across the three years of study, SRI produced significantly greater plant biomass and grain yield than Non-SRI. The yield increase was mostly ascribed for the increased number of grains per land area, which was due to the increased number of spikelets per panicle rather than the number of panicles per land area. With no significant difference between SRI and Non-SRI with respect to seedling age, the greater number of grains per panicle was accounted for by the reduced planting density and increased amount of manure application in SRI than Non-SRI fields. It was found that the greater manure application has increased soil nitrogen content in SRI and Non-SRI fields. While SRI did not increase the number of panicles per land area, it did increase the number of panicles per hill.