• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.31 no.3
• /
• pp.318-325
• /
• 1986

The studies were performed to obtain the basic informations on the influence of weather condition for grain yield and yield components in barley. The data of Olbori tested in 9 sites for 12 years were used in the studies. Milled grain yield was decreased in paddy field after rice harvested comparing to the upland condition, and yield potential was differed by test sites with the most stable yield in Gyeongnam. The coefficients of variation analyzed for milled grain yield by years were 12.2-42.6% with the differences between high-yield and low-yield year. Heading date was earlier in high-yield year and southern part compared to the low-yield year and middle part of the Korean peninsular showing the negative correlation between grain yield and heading date. High-yield year showed longer in culm length, shorter in spike length, almost same in number of grains per spike, and lower in 1,000grain weight compared to the low-yield year. Correlation analyzed between number of spikes and grain yield showed positive relationship. Temperatures affected to the grain yield analyzed by high in vegitative growth stage, low in alternative growth stage, and almost same in reproductive growth stage in high-yield year comparing to the low-yield year, however no remarkable differences of temperatures affected were detected in over wintering stage between high-yield and low-yield year. Precipitation amount in high-yield year was lesser in sowing time, more in seedling time, and lesser in over wintering time than those of the low-yield year. Correlation between rainfall amount in the early of April and grain yield showed significant negative correlation with the remarkable affects to the grain yield. Sunshine hours in high-yield year were longer in sowing time, shorter in over wintering time, and after the over wintering time to harvesting time was longer than those of the low-yie-ld year.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.197-197
• /
• 2017

In order to reduce the loss of perilla seeds at harvesting stage, different seeding methods and harvesting time had been applied to upland soil in NICS (National Institute of Crop Science), RDA, Milyang, Korea. The seeding methods were divided into hill and drill seeding, and harvesting time were 40%, 60%, 80%, and 100% color-changing of top cluster perilla (cv Deulsaem) seeds. Higher plant height and lowest flower cluster, thinner culm thickness was observed in drill seeding treated plot than hill seeding treated plot. However, field lodging occurred lower at drill seeding treatment (lodging degree 3) than hill seeding plot (lodging degree 5). Harvesting time affected the loss of perilla seeds and the loss rate of perilla seeds were investigated at different color-changing of top flower cluster. When seeds were harvested at 40%, 60%, 80%, and 100% color-changing of top cluster perilla seeds, the loss rate of hill and drill seeding showed no significant differences however the loss rated of 40, 60, 80, and 100 % color-changing of top flower cluster were 1.9% to 3.0%, 3.8% to 3.9%, 8.0% to 10.2%, and 16.1% to 22.7%, respectively. The harvesting time had no significant effects on the yield of perilla seeds. These results suggest that optimum harvesting time of perilla could be recommend at the 60% color-changing of top cluster to reduce the loss of perilla seeds.

• Korean Journal of Environmental Agriculture
• /
• v.22 no.4
• /
• pp.241-245
• /
• 2003

This study was carried out to evaluate the status of the groundwater quality for paddy fields irrigation in Korea. Water samples were collected at 130 sites throughout the country. Samples were collected at three seasons - April, July and October - in 2000. According to our survey, the groundwater was found to be suitable for irrigation purpose. Average EC was shown 0.286 dS/m. Nitrate-nitrogen and $Cl^-$ concentration was 5.6 mg/L, 32.95 mg/L which satisfied the Korean Standards for Irrigation Water. Nitrate-nitrogen concentration in each province was shown as following orders: Jeju (11.17 mg/L) > Chungnam (8.16 mg/L) > Gyeongbuk (6.64 mg/L) > Gyounggi (5.91 mg/L) > Chungnam (4.95 mg/L) > Gyeongnam (3.91 mg/L) > Jeonbuk (3.50 mg/L) > Jeonnam (3.27 mg/L) > Gangwon (2.91 mg/L). The concentration by sampling seasons were October (6.62 mg/L) > July (5.88 mg/L) > April (4.78 mg/L). As the soil of Jeju Province is usually derived from volcanic ash soils mainly used for upland drops, it may influence the nitrate-nitrogen concentration of groundwater. The amount of rainfall also influence the water quality. But the $COD_{Cr}$ were shown April (3.17 mg/L) > July (2.91 mg/L) > October (2.40 mg/L), it is highly related in the basal dose of organic matter fertilizers. This study demonstrated that groundwater quality was suitable for irrigation, but continuous monitoring is recommended for agricultural policy and developing OECD agricultural environment indicators.

• Ecology and Resilient Infrastructure
• /
• v.7 no.1
• /
• pp.63-71
• /
• 2020

Various types of amendments have been studied for heavy metal stabilization in soil. However, researches on the effect of amendments on alkali soil and their effects on the plants at various edible parts are insufficient. The aim of this study was to evaluate the stabilization efficiency of heavy metals and their transfer into edible parts of food crops. Abandoned mine area was selected and 3 types of amendments (lime stone, LS; steel slag, SS; acid mine drainage sludge, AMDS) was applied with 3% (w/w). in field. After 6 month aging, Chinese cabbage (leafy), bok choy (leafy), garlic (root) and red pepper (fruit) were transplanted and cultivated. For chemical assessment, total concentration and bioavailability using Mehlich-3 solution were determined. For biological assessment, fresh weight and heavy metal uptakes were analyzed. It was revealed that AMDS reduced bioavailability most effectively, resulting in the decrease in heavy metal concentration in edible parts of all crops. When explaining the heavy metal uptake of plants, the bioavailability was more appropriate than the total contents of soil heavy metals. Therefore, bioavailability-based further research and management practices should be carried out continuously for the sustainable environment management, safe crop production, and human health risk reduction.

• Korean Journal of Soil Science and Fertilizer
• /
• v.37 no.4
• /
• pp.245-250
• /
• 2004

Farmers typically apply the dressed soil (coarse saprolite) for various reasons in the sloped upland with high altitude in Kangwon province. However, little researches on the impacts of application of dressed soil in uplands were conducted. Therefore, it is necessary to assess soil quality in this area and to study adverse effects on soil and water due to application of dressed soil. Coarse saprolite itself showed signiScantly poor chemical properties, Particularly P and organic matter contents were not enough for crops to grow. With respect to biological qualities such as enzyme activity and microbial population, coarse saprolite itself showed poor qualities. For example, bacterial population in coarse saprolite contains six times or ten times smaller populations. Based on survey at Jawoon-ri in Hongchon-gun, this region is susceptible for soil erosion due to massive amounts of coarse saprolite application, undesirably long slope length, etc. When weestimated soil loss, more than 40% of farming field in this region exceeded $11.2MT\;ha^{-1}\;yr^{-1}$. According to experiment by installing sediment basins. the sediment basin with up-down tillage and application with dressed soil had the highest soil loss and runofT, while the sediment basin with contour tillage and without soil dressing showed the lowest soil erosion and runoff.

• Korean Journal of Soil Science and Fertilizer
• /
• v.25 no.1
• /
• pp.70-76
• /
• 1992

A field experiment was conducted to find out the influence of cropping systems under rotation of paddy-upland soil on soil microorganisms with specific reference to cations concentration in the soil. The results obtained was summarized as follows. 1. The number of soil bacteria and actinomycetes increased in fallow, continuous cultivation of rice and soybean while the number of fungi decreased. 2. Gram negative bacteria as Pseudomonas spp. and Rhizobium spp. remarkably incerased with increasing Gram positive bacteria of Bacillus subtilis in continuous cultivatio of soybean. 3. The relative population of soil born plant pathogen such as Fusarium spp. Rhizoctionia spp. and Phoma spp. to the total soil fungi was high in cultivation of potato and Chinese cabbage. The ratio of soil plant pathogen to the total soil fungi was high in cultivation of potato with Chinese cabbage. 4. The number of bacteria and actinomycetes was positively correlated with ratio of Ca＋Mg/K in soil while negatively correlated with soil fungi.

• Korean Journal of Environmental Biology
• /
• v.25 no.3
• /
• pp.223-227
• /
• 2007

Crop loss and damage by wildlife are becoming more serious to residents inside and around National Parks of Korea annually. It could be caused by small size of Parks, which is couples of ten $km^2$ only, and more than a third of total parks' areas are belonging to privates. Wild boar (Sus scrofa) is one of the most harmful pests in nationwide. Treading down crop field using as bedding or resting site are major damaged types and foraging behavior is following. Besides of boars, Korean water deer (Hydropotes inermis), racoon dog (Nyctereutes procyonoides), and badger (Meles meles) are another serious pests. Mainly, farm products planted in upland, such as corns, sweet potatoes, cabbages, etc. are harmed easily, a rate reaches up to 76.9% of whole losses. 92.4% (n=187) of interviewees, who are mostly seniors, cultivate small crop fields smaller than 1 ha. Crop damage would be started from June to late November, time differences are happened due to latitude, climate condition, and crop differences of National Parks. Dusting animal repellents are easier and widespread methods to prevent animal foraging to crop fields and installing noisy makers using gun powder and setting up scarecrows are traditional methods for repelling animals. Nevertheless, effects of these self-defence are turned out to be useful soon after labors done only. Since legal compensation for crop damages by wildlife are not prepared systematically so far, crop loss are rarely reported to local government by most farmers. Systematic and objective methods for quantifying of crop loss by wildlife and population managements system should be offered urgently to well-managed animals habitat and residents' living inside National Parks.

• Korean Journal of Organic Agriculture
• /
• v.17 no.4
• /
• pp.501-517
• /
• 2009

This research was carried out to study the effect of mulching materials and weed control methods on weed occurrence and growth of kale on upland and paddy soil of field culture at spring and autumn season. Paddy soil temperature of mulching treatments was high by $0.9{\sim}2.0^{\circ}C$ in comparison of non-mulching at autumn season. The control value of weed was over 91% at mulch paper and time required for weed control was reduced by 70% at mulch paper + machine weeding in comparison of non-mulching + hand weeding. The yield of kale was similar to that of conventional culture. Paddy soil temperature of mulch paper was higher on April, but lower on May and June than non-mulching at spring season. Dominant weed was Chenopodium album var. centrorubrum Makino, The control value of weed was over 91% at mulch paper, time required for weed control was reduced by 75% at mulch paper + machine weeding in comparison of non-mulching + hand weeding and the yield of kale increased by 34% than conventional culture. Dominant weed was Alopecurus aequalis var. amurensis Ohwi. on paddy soil at autumn season. The control value of weed was 43% at mulch paper. Time required for weed control was reduced by 80% at mulch paper + machine weeding in comparison of non-mulching + hand weeding. The yield of kale increased by 26% compared with than of conventional culture.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.3
• /
• pp.367-372
• /
• 1997

Excessive water stress is one of major limiting factors affecting soybean yield, especially when soybean is grown in converted upland from paddy field. The present study was undertaken to know the genotypic variation in yield response of soybean to different environments in combination with soil texture and underground water table depth. Eight recommended soybean varieties in Korea and two supernodulating soybean mutants introduced from USA were planted in the lysimeter which was filled with two different soil types(sandy loam and clay loam). Of three underground water table depths(10, 30, and 50 cm) during whole growth stage, the lowest 10 cm was included to create excessive water stress. Yield was significantly different according to the underground water table depth and soybean genotypes, whereas soil type did not affect yield. There were significant interaction effects of soybean yield among soil type, soybean genotype, and underground water table depth. Yield of nts 1116 showed the highest across environments. Based on the regression analysis, the most stable variety was Sobaeknamulkong(bi=1.09). Jangsukong was fairly stable and high in yield, when compared to other soybean genotypes. However, nts 1116 was the most desirable ($D_i=228$) mainly due to the highest yield rather than the greater stability over environments. Multiple regression analysis revealed that shoot dry weight and nodule number were major factors affecting yield in the combined data over three water table depths and two soil types.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.61 no.1
• /
• pp.41-49
• /
• 2016

This study was conducted to evaluate maize downy mildew resistance using spreader row technique in Cambodia. A total of forty maize lines were used in this experiment. Seven Korean varieties and seven breeding lines showed high infection rates (80~100%) and highly susceptible (HS) to downy mildew disease in both spring and fall. Also most of nested association mapping (NAM) parent lines were highly susceptible (HS). Meanwhile three inbred lines, Ki3, Ki11, and CML228, showed highly resistant (HR) or resistant (R) in spring and moderately resistant (MR) in fall. These three lines were already known as resistant inbred lines against downy mildew disease. It appears that spreader row technique was suitable for selection of maize downy mildew resistance in Cambodia. The incidence of downy mildew was influenced by weather conditions, especially relative humidity and temperature. Among several inoculation methods to screen for downy mildew resistance, this spreader row technique is effectively and easily used in the field of Southeast Asia.