• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.41 no.1
• /
• pp.68-76
• /
• 1996

To elucidate the optimum fertilizer level and application method for band application under puddled-soil drill seeding in Jeonbuk series of fluvio-marine alluvial soil at National Honam Agricultural Experiment Station in 1995, using Dongjinbyeo, slow releasing compound fertilizer of 100％ and 80％ to conventional application level was applied totally as basal fertilizer simultaneously with seeding under 3cm and 5cm depth from soil surface in a distance of 4cm from the seeded row. Plant height was taller and tiller number was higher in band application than conventional application but ratio of effective tiller was vice versa. Panicle number was more but ratio of effective tiller ratio was lower in 100％ than 80％ level of band application and they were higher in 3cm than 5cm depth from soil surface. Leaf area index and dry weight was higher in conventional application at early growth stage but was vice versa after maximum tillering stage, and they were higher in 3cm depth at early growth stage but 5cm depth after maximum tillering stage. NH$_4$-N in soil was higher in conventional application at 25 days after seeding but, thereafter was lower than band application and it was higher in 3cm than 5cm depth till 40 days after seeding but was versa, thereafter. Lodging degree was slightly higher in band application, 100％ level and 5cm depth than in their counterparts. Panicle number and grain number per $m^2$ was lower in conventional application than 80％ or 100％ level of band application without significant difference between band application levels or application methods. Yield was higher at 80％ level of band application under 3cm depth than conventional application, but no significantly different among other application methods. Therefore, 80％ level of band application under 3cm depth of soil surface was more effective for puddled-soil drill seeding on the basis of the reduction of application efforts, better plant growth and higher yield in rice.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.13 no.3
• /
• pp.2349-2371
• /
• 1971

1. The historical development of the agriculture in Korea is observed and the future of Korean agriculture is suggested with present situation in order to recommend a direction of policy in agricultural mechanization. 2. A factor analysis of agricultural mechanization The needs of agricultural mechanization in the view of both national need and the armer's desire under the present situation are analyzed with data from the various sources. The researcher found that the agricultural mechanization is badly needed to develop prospective Korean agriculture to future. 3. The direction of agricultural mechanization. It can be said that the position of agriculture in the national economy plays a very important role. This importance should not be ignored by the Politicians in their process of developing long range economy plan. The agricultural mechanization for the modernized Korean agriculture should be directed to increase the most effective results with minimize the least sacrifice. The merry tiller is recommended to the main agricultural machinery in Korea in order to meet its small farming operation un-its(or farm size). Tractor is recommended in the plain area for the crop cultivation. The cooperative cultivation for rice and the upland crops will be developed in the plain area. Tractor, therefore, is recommended for the main agricultural machinery in these areas. Either tractor or merry tiller is recommended to the orchard area by its operating size of the orchard. The researcher also disoussed about the development of animal husbandry on the farm with increasing the farm size in order to develop meadow and pasture nuder the consideration of both the improvement of food consumption and the comprehensive development of national resources. 4. Relationship between the Performance of various agricultural machinery and the economic scale. Because of the agricultural machinery needs an expensive fixed expense(fixed cost) the total expense Per ha of the fixed expense and the operation expense should less than the traditional expense Per Dan Bo with in creased corpgiclds Per Dan Bo. Since the anual fixed expense of the agricultural machinery is figured out by the durability the more the farm size the less fixed expense of machinery is required. The formula of this principle is as follows; fixed expense for Dan Bo=Fixed expense of agricultural machinery farm size(or farming scale) The breaking-even point is the balance point between the expense of the using agricultural machinery and the traditional farming expenses. Labor cost of the Dan Bo is increasing when the management scale increases by the tradititional farming while the machanized management decrease the management cost Per Dan Bo. The reseracher found that the distribution of agricultural machinery will be the adeventeous after the year of 1981 by the result of frguring out the breaking-even point. 5. The Investigate and the conclusion. The purpose of this study is found out the direction of agricultural machanization and the breaking-even point of various agricultural machinery, there for is found out effective of the using various agricultural machinery for Collection cutter, Binder, Footing thresser, Semi-power thresser, Power thresser, Combine, Power rice-Trans-Planter, etc.

• Journal of Biosystems Engineering
• /
• v.3 no.2
• /
• pp.22-33
• /
• 1978

To maintain the self-sufficiency of food production , it is required to improved the productivity and increase the effective utilization of land in the double cropping areas using improved cultivation technology. The following reasons encourage this cours of action because the overlapping rice harvest and barely seeding seasons complete for labour, the lower price of barley makes it financially less attractive to grow and these two facts together are responsible for a decrease in barley being planted in certain more seasonably marginal double cropping areas. Fro these reasons, it is desirable to carry out tests to improve the current cultivation techniques . In this interest , the following studies were carried out in the experimental field located at Banweol-myeon, Whasung-jkun, Gyeonggi-do from October 1977 to July 1978 in order to establish the mechanical method of barley cultivation using the power tiller. The summarized results are as follows. 1. The work performance in the seeding operation using the rotary barley seeder was 68 minutes per 10 ares which compares favourably with 408 min/10a using the conventional method. This is only one sixth of the time required by th conventional method. The operating costs using the rotary barley seeder was 1, 463 won per 10 areas as against 3, 486 Won per 10 ares for the conventional method, showing a saving of about 50% in comparison with the conventional method. 2. In the manure spreading operation, the work performance was 25 min/10a for the manure spreading machine , compared to 1089 min/10a for the manual operations. This is about one fourth of the time required by the conventional method, The operating costs were 810 Won/10a for the machine and 857 Won/10a for the manual labour. This cost shows little advantage by the machine over the manual labor costs. The conventional method of manure spreading will continue pending decision which will develope and improve the machine.3. Work performance in the rolling operation using the barley rolIer was 30 min/lOa which compares favourably with 135 min/10a using conventional method. This was one fourth of the time required by the conventional method. The operating costs were 514 Won/103. for the machine and 1, 003 Won/lOa for manual labour. In the weed control operation, the work performance and operating costs were 45min/lOa, 1, 399won/10a for the herbcide application using the power sprayer, 1, 149min/10a 8, 541won/lOa for the conventional method respectively. This is 26 times higher efficiency in comparison to the conventional method. 4. In the harvesting operation using the reaper binder and tiller attachment, the work performance was 60min/lOa and represents a cost of 2, 039won/10a. The con\ulcornerventional method took 640min/10a at a cost of 4, 757won/lOa. The reaper binder showns a saving of one tenth over the conventional method. The automatic thresher is already recommended for the current situations, and is now being used. 5. From a comparison of the results of the above trials, the serial cultivation system using the attachment for the power tiller such as the rotary barley seeder is now to be recommended for the current barley cultivation system. It is also recommend from these results that the mechanized technology now available must be used to improve and maintain the increase in barley production. It is seen th1t this is the only course now avaihble to solve the peak seasonal requirements of labour needed for l11rvesting and seeding between rice and barley cultivation.

• Korean Journal of Agricultural Science
• /
• v.12 no.2
• /
• pp.174-182
• /
• 1985

In order to obtain information necessary for attaining maximum yield of rice by increasing nitrogen efficiency, effects of top dressing of nitrogen fertilizer at the later part of growing season were investigated and results obtained are summurized as follows: 1. The increased application of nitrogen fertilizer was very effective in increasing leaf areas and net assimilation rate of rice plants. The spikelets number per hill was also increased due to heavy nitrogen fertilizer. 2. The concentrated top dressing at the later part of plant growth apparently increased the crop growth rate at the reproduction stage and ripening stage of rice, respectively. The nitrogen efficiency was greatly improved by the concentrated top nitrogen dressing through the increase of effective tiller number and the improvement of production organ to non productive organ ratio. 3. The concentrated top nitrogen dressing at the later growing season was considered to be one of the most effective methods of fertilizer applications as well as cultivation of fertilizer resistant varieties for the high yield of rice and improving soil fertility.

• Journal of Ecology and Environment
• /
• v.42 no.1
• /
• pp.43-49
• /
• 2018

Iris laevigata is geographically restricted and legally protected in Korea. In this study, a mesocosm study was conducted to examine the effects of environmental conditions such as water levels and soil nutrient conditions on the growth and survival of I. laevigata seedlings. Complete submergence lowered the total number of leaves, biomass, and survival rates. A rise in soil nutrients increased overall seedling growth and increased tiller numbers via the promotion of asexual reproduction. Also, we found that the lowest measured values of seedlings are associated with the most stressful condition due to the interaction of low soil nutrients and high water levels. I. laevigata seedlings, however, are distributed in low-nutrient habitats such as floating mat, even though they do not grow well under these conditions. This study suggests that I. laevigata does not prefer low-nutrient condition but choose another benefit such as low competition. Also, the water level must be lower than the seedling height for effective growth and management of I. laevigata.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.37 no.5
• /
• pp.405-412
• /
• 1992

Growth characters of dry seeded paddy rice was studied at different levels of nitrogen(N) split application (basal : immediately after irrigation : 2 weeks after irrigation: 25 days before heading: heading stage with 10 : 20 : 30 : 20 : 20%, 20 : 30 : 20 : 20 : 10%, 30 : 40 : 0 : 20 : 10%, and 100% basal of slow release urea) in tillage and no-tillage systems. On May 17 in 1990, 6kg /10a of dry seeds of a breeding line of Milyang 95 was broadcasted and covered with a power tiller. Between tillage and no-tillage systems yield and its components, lodging related characteristics, and contents of cellulose, hemicellulose and lignin of culm base were similar. Leaf area index at heading stage was higher in tillage, but lodging index was lower compared with those in no-tillage plot. Culm length, effective tiller ratio, culm base weight, 1000-grain weight, harvest index in slow release N applied plot were higher compared with those in other N treatments. Grain yield of rice among levels of N split applications was similar in tillage, but it was higher in slow release N applied plot in no-tillage if 1kg /10a of additional N was applied as urea at panicle formation stage. At early growth stage N concentration and N uptake were lower in the slow release N applied plot, but higher after heading stage compared with other N treatments. The number of tillers was lowest in slow release N applied plot during the tillering stage, but the number of panicles per hill was similar to other N treatments.

• Asian Journal of Turfgrass Science
• /
• v.20 no.1
• /
• pp.25-31
• /
• 2006

'Meyer' zoysiagrass(Zoysia japonica Steud.) is a popular turfgrass species used for transition zone golf course fairways and tees in mfd U.S.A golf courses because it is generally winter hardy while providing an excellent playing surface with minimal chemical and irrigation inputs. However, its functionality declines easily in many of the shaded areas of these courses. Reduced irradiance causes excessive shoot elongation, reduced tillering, and weak plants that are poorly suited to tolerate or recover from traffic and devoting. Trinexapac-ethyl (TE) effectively reduces gibberellic acid (GA) biosynthesis and subsequent shoot cell elongation. This study was initiated to evaluate TE effect on shoot elongation and stand persistence under two levels of shade in 'Meyer' zoysiagrass. A mature stand of 'Meyer' was treated with all combinations of three levels of shade(0%, 79%, and 92%) and three levels of monthly TE [0, 48 $g{\cdot}ha^{-1}$ a.i(0.5x) and 96 $g{\cdot}ha^{-1}$ a.i(1x)]. In full sun, the TE at 48 $g{\cdot}ha^{-1}$ a.i reduced clipping yield by 18% over a four-week period and, whereas the TE at 96 $g{\cdot}ha^{-1}$ a.i by 30% to 38%. Monthly application of TE at the 96 $g{\cdot}ha^{-1}$ a.i increased 'Meyer' tiller density in full sun and under 79% shade. Both rates of TE consistently reduced shoot growth under shade relative to the shaded control. Only the monthly applications of the TE at 96 $g{\cdot}ha^{-1}$ a.i consistently delayed loss of quality under 79% shade. Our results indicate TE can be an effective management practice to increase 'Meyer' zoysiagrass persistence in shaded environments.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.29 no.4
• /
• pp.386-393
• /
• 1984

This study was carried out to identify the ecological characters easily changeable with the conditions of temperature and day-length and to ascertain the managable means which can optimize the barley plants to secure the maximae yield and early heading under controlled condition. Yield and yield components were greatly varied with temperature. Especially, effective tiller formation and grain filling of sub-tillers were more favorably affected by thermal treatment than those of main tiller. In thermic response, 'Kangbori' was less susceptible than others, while 'Sacheon #6' showed particular susceptability. The varietal differences of photoperiodic response were recognized on all investigated traits and their degree of response were similar to those with temperature. Among varieties, 'Kangbori' was comparably sensitive on several characters while 'Sacheon #6' displaying low light-sensitivity. The turning point at which heading might be radically stimulated was estimated as about 10.5 hour day-length in 3 tested varieties and above 18 hours of irradiance was considered ineffective for more rapid heading. The condition under which barley varieties may obtain maximal yield and resonably early heading was 15$^{\circ}C$ in temperature and 12 to 15 hours of day-length, regardless of varieties. of day-length, regardless of varieties.

• Korean Journal of Plant Resources
• /
• v.29 no.4
• /
• pp.511-518
• /
• 2016

The subject of this experiment is to supply basic data to inhibit non-productive tillers which are uneconomical for mechanical harvesting and to evaluate optimum planting density and sowing date in central district. Total number of tillers and effective first and second of tillers according to different planting density was higher in 80 ㎝ ridge than 60 ㎝ ridge in proso millet. The wider between plant distance on the ridge, the more increased total number of tillers and effective first and second of tillers. The highest effective tillers (91.7 %) in the first tillers was obtained from the second sowing date (23 May) among different sowing date and next is in the order of 3^rd(13 June, 89.8%) > 1^st(2 May, 85.6%) > 4^th(4 July, 85.2%). The percentage of effective tillers in the second tillers was decreased in the order of 2 May (53.7%), 23 May (40.7%), 13 June (22.2%), 4 July (0%) as the sowing date was delayed. There was no significant difference in days to heading and days to ripening according to different planting density. Although culm length was increased as planting density was increased, whereas number of tillers, stem diameter, ear length, grains per ear and 1000 grain weight was decreased. In the growth and yield characteristics of proso millet according to different sowing date, days to heading and days to ripening, culm length, stem diameter, ear length, grains per ear and yield per 10a were decreased. After the sowing date of 13 June, the reduction of growth and yield characteristics were higher because of excess-moisture injury.

• Korean Journal of Weed Science
• /
• v.3 no.1
• /
• pp.29-38
• /
• 1983

Growth habit, intraspecific competition of Digitaria sanguinalis, and interspecific competition between soybean and D. sanguinalis were evaluated to obtain the basic informations on establishing an effective control measure in upland corps. The earlier planting on April 1 produced approximately 3.5 times higher dry matter than that of the latest planting on July 22 and resulted in the earliest heading on July 8 and the latest heading was observed on September 4 planted on July. 22, but the interval between planting and heading dates was shortened progressively as the planting dates were delayed, showing irregularity of heading within a hill. Tiller numbers per plant were inhibited as densities increased from one to forty. One plant planted per pot produced significantly higher tiller numbers than density of 5 to 40 plants per pot. However, total tiller numbers was the highest in density of 40 plants planted per pot. Regardless of planting densities used, D. sanguinalis at all densities produced the similar dry matter per pot, showing severe intraspecific competition as density increased, but on each plant basis dry weight production was the highest in the lowest density such as one plant planted per pot. Competition between soybean and D. sanguinalis for the entire growing season decreased the total dry weight of soybean by 59.6%. Soybean required the maintenance of a weed free condition, about 3 to 4 weeks immediately after seeding, for obtaining the maximum yield, beyond which soybean crops effectively suppressed the growth of D. sanguinalis.