• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.441-448
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• 2012

This study was carried out to evaluate the productivity of rice cultivation in extremely late season in Korea and to confirm the effects of pot-raising seedling culture in this case by assessing the growth and yield performance of rice cultivars that are well adapted to late culture. Suitable cultivars for extremely late culture should not have premature heading habit when transplanted around late July and also secure appropriate growth duration before heading. Geumobyeo 1 and Manjongbyeo showed small decrease in the emerged leaves in transplanting in late July or early August and heading occurred at the same time relatively without premature heading. At transplanting from late July to early August in extremely late rice cultivation, ripening was relatively good until transplanting on August 5. At transplanting on July 30, accumulated temperature from heading to the first frost was $853^{\circ}C$ and ripening was good enough. However, heading was delayed by low temperature at transplanting on August 10 and ripening was very poor due to low accumulated temperature of below $800^{\circ}C$, causing drastic decrease of rice yield. The rice yield increased in transplanting with pot seedling, especially the effects of pot seedling was higher in Geumobyeo 1, but panicle number was not enough to secure rice yield owing to short growth duration. In order to cultivate rice in extremely late season, we should select adaptive rice cultivars that have suitable growth duration and excellent ripening in low temperature. Here, pot-seedling did a great role to secure early growth and bigger growth amounts.

• Journal of the Korean Society of International Agriculture
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• v.23 no.5
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• pp.520-530
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• 2011

This study was carried out to evaluate the possibility of rice double cropping in Korea by assessing the growth and yield performance of rice cultivars transplanted at the extremely-early date. When the transplanted rice seedling was exposed to low temperature below 0℃, the survival rate decreased drastically. However, short exposure to below 0℃ one or two times did not damage transplanted rice seedling so severely. Thus, the earliest transplanting in spring would be possible when minimum temperature rises above 0℃. Compared with the conventional seedling nursery tray (CSNT), seedling rearing with the potted nursery tray was more effective for increasing leaf age and seedling dry weight during nursery period. In the first rice cropping, rice cultivation with seedlings reared in PSNT showed shorter growth duration and cumulative temperature from transplanting to heading than that with seedlings reared in CSNT. The earliest heading date on July 4 in Jinbuolbyeo was earlier by two to three days than that of Dunaebyeo. If rice has not exposed to cold damage, the earliest heading date of Jinbujolbyeo can advance to June 30 or July 1. In this case, rice harvest would be possible on August 5, enabling the rice transplanting of the second rice cropping before August 10. At transplanting time with low temperature damage rice yield were less than 400 kg/10a while rice yield exceeded 400 kg/10a at transplanting time without low temperature damage.

• Applied Biological Chemistry
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• v.16 no.3
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• pp.146-165
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• 1973

Crop damages caused by sulfur dioxide poisoning were studied with respect to physiology of lesion, yield loss and prevention measures. The results are summarized as follows; 1. On the physiology of injury: The sulfur dioxide gas did no: affect the pH and $E_h$ values of the tested leaf juice of plants. Peroxidase activity was inhibited just after sulfur dioxide treatment but gradually recovered to normal after 10 hours. Methanolic chlorophyll solution was instantaneously and irreversibly bleached by the addition of sulfur dioxide gas with no evidence of pheophytin formation. It seems that chlorophyll forms colourless addition product or is reduced to colourless form with either sulfur dioxide gas or sulfurous acid. Chlorophyll in the chloroplast was also bleached by the sulfur dioxide treatment, as in the case of methanolic solution of chlorophyll, except that the rate of bleaching was rather slow, requiring 1-2 hours. It appears that the most inflicting cause of sulfur dioxide gas to plants may be the destruction of chlorophyll by the poisoning gas. 2. On the effects to crop yield: The crop yield losses were proportional to the concentration of inflicting sulfur dioxide gas. The order of tolerence of the crops to the sulfur dioxide gas was as follows - chinese cabbage being the most susceptible; wheat, paddy rice, barley, soybean, welsh onion, radish and chinese cabbage. The crucifer crops were generally found more susceptible than other crops studied. With respect to the growing stages of crops exposed to sulfur dioxide gas, it was found that the flowering stage was the most susceptible fellowed by panicle forming, milky and tillering in the decreasing order of susceptibility. 3. On the preventive measures of yield losses: Soil applications of potassium, wollastonite, lime or spray of lime water were effective to prevent yield losses from sulfur dioxide fumigation of paddy rice, barley, and soybeans. The most responsive treatment was lime water spray for all crops tested. In case of sulfur dioxide fumigated paddy rice, the lime water spray also increased carbon assimilation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.2
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• pp.106-110
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• 2020

The purpose of this study was to evaluate winter annual forage crops for yield, and horse palatability under horse grazing during the fall and spring in Jeju. The winter annual forage crops such as Italian ryegrass(IRG), rye, and oat were planted in randomized block design in October 30. The horse grazing was initiated on March 17 of the following year. At the first cutting, the dry matter yield of rye was the highest with 4,600 kg/ha compared to the IRG and oat (p<0.05). But there were no significantly different in the yield of winter annual forage crops after the second and third harvests. The total dry matter yield showed rye 12,593 kg/ha, IRG 10,941 kg/ha, and oat 9,424 kg/ha respectively. The horse intake duration of the IRG was significantly higher than the oat and rye (p<0.05). In the first grazing and the second grazing, the intake duration of the IRG was 853.2 seconds and 989.4 seconds, respectively, with oat at 147.6 seconds, and 73.0 seconds, and rye at 89.4 seconds, and 33.18 seconds. The intake duration of IRG was longer than that of oat and rye (p<0.05). The intake rate of the IRG was 60.0% in the first and 82.8% in the second, and the average intake rate was 71.4%. When considering the maintenance of pastures and the palatability of horses, the IRG is the most suitable forage crop in winter annual forage crops in Jeju.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.2
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• pp.129-135
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• 2013

This study was conducted to investigate the soil characteristics of newly reclaimed tidal land and the effect of green manure crops on soil properties. Summer green manure crops such as sesbania (Sesbania grandiflora), barnyard grass (Echinochloa spp.) and sorghum${\times}$sudangrass hybrid (Sorghum bicolor L.) were cultivated at Hwaong, Ewon, Saemangeum and Yongsangang area. Soil pH of reclaimed tidal land was relatively high, but organic matter and available phosphorus contents were lower compared to the optimum range for common upland crops. Soil nutrient contents were unbalanced for upland crop growth. Yield of green manure crops had a wide spatial variation. Nitrogen content in green manure crops was the greater in Sesbania and it was estimated that major nutrient ($N-P_2O_5-K_2O$) supply amount were 150-40-370, 220-50-170 and 140-50-250 $kg\;ha^{-1}$ from sorghum${\times}$sudangrass hybrid, sesbania and barnyard grass, respectively. Based on these results, desalination is required to grow the upland crops at newly reclaimed tidal lands and management practices are necessary to reduce the salt damage by resalinization during the growing seasons. To improve the productivity and increase the nutrient utilization rate, soil physicochemical properties need to be improved to the level for upland crops by application of organic matter and fertilizer.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.2
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• pp.145-152
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• 2020

In this paper, we propose the Crop Classification Management System (CCMS) that detects changes in growth environment to improve crop production rate. The CCMS consists of two modules. First, the Crop Classification Module (CCM) classifies crops through CNN. Second, the Farm Anomaly Detection Module (FADM) detects abnormal crops by comparing accumulated data of farms. The CCM recognizes crops currently grown on farms and sends them to the FADM, and the FADM picks up the weather data from the past to the present day of the farm growing the crops and applies them to the Nelson rules. The FADM uses the Nelson rules to find out weather data that has occurred and adjust farm conditions through IoT devices. The performance analysis of CCMS showed that the CCM had a crop classification accuracy of about 90%, and the FADM improved the estimated yield by up to about 30%. In other words, managing farms through the CCMS can help increase the yield of smart farms.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.351-351
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• 2017

Arbuscular mycorrhizal fungi (AMF) are particular soil fungi that benefit many crops and require a symbiosis with plant roots to survive. In our previous study, there was a positive correlation between AMF root colonization and soybean grain yield in a four-year consecutive winter cover crop-soybean rotational system without phosphorus fertilizer. It is suggested that higher AMF root colonization can be a better solution for improving soybean growth and grain yield in P-limited soil. Our purpose in this study was to test the hypothesis that a P application is the main factor improving soybean growth, P nutrition and grain yield, and the benefit from AMF to soybean P uptake and growth in a P-limited soil. Impact of a P application on AMF root colonization and communities in soybean roots and their potential contribution to soybean growth and P nutrition under a five-year P-unfertilized crop rotational system were investigated over two-years. In this study, four cover crop treatments included 1) wheat (Triticum aestivum); 2) red clover (Trifolium pratense); 3) rapeseed (Brassica napus); and 4) fallow in the crop rotation. The amount of triple superphosphate as a P fertilizer applied rate after cultivation of cover crops was 120 and $360k\;ha^{-1}$ in 2014 and 2015, respectively. Soybean roots were sampled at full-flowering and analyzed for AMF communities using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and quantitative real-time PCR (qPCR) techniques. The AMF root colonization in the soybean roots at full bloom stage was significantly influenced by cover crop and P application throughout the two-year rotation. The two-year rotation of different cover crops or fallow impacted the molecular diversity of AMF communities colonizing roots of soybean. Redundancy analysis (RDA) indicated that AMF communities colonizing roots of soybean were significantly different among cover crop rotations. The AMF communities colonizing roots of soybean were clearly influenced by a P application in the two-year trial. Moreover, a P application may have positively impacts on the AMF communities under P-deficit soil due to the continuous cover crop-soybean rotational system without a P fertilizer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.4
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• pp.296-313
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• 1982

At a time when world population and food supply are in a delicate balance, it is essential that we look at factors to improve this balance. We can alter the environment to better fit the plant's needs, or we can alter the plant to better fit the environment. Improved technology has allowed us to increase the yield level. For moderately detrimental weather events technology has generally decreased the yield variation, yet for major weather disasters the variation has increased. We have raised the upper level, but zero is still the bottom level. As we concentrate the production of particular crops into limited areas where the environment is closest to optimum, we may be increasing the risk of a major weather related disaster. We need to evaluate the degree of variability of different crops, and how weather and technology can interact to affect it. The natural limits of crop production are imposed by important ecological factors. Production is a function of the climate, the soil, and the crop and all activities related to them. In looking at the environment of a crop we must recognize these are individuals, populations and ecosystems. Under intensive agriculture we try to limit the competition to one desired species. The environment is made up of a complex of factors; radiation, moisture, temperature and wind, among others. Plant response to the environment is due to the interaction of all of these factors, yet in attempting to understand them we often examine each factor individually. Variation in crop yields is primarily a function of limiting environmental parameters. Various weather parameters will be discussed, with emphasis placed on how they impact on crop production. Although solar radiation is a driving force in crop production, it often shows little relationship to yield variation. Water may enter into crop production as both a limiting and excessive factor. The effects of moisture deficiency have received much more attention than moisture excess. In many areas of the world, a very significant portion of yield variation is due to variation in the moisture factor. Temperature imposes limits on where crops can be grown, and the type of crop that can be grown in an area. High temperature effects are often combined with deficient moisture effects. Cool temperatures determine the limits in which crops can be grown. Growing degree units, or heat accumulations, have often been used as a means of explaining many temperature effects. Methods for explaining chilling effects are more limited.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.4
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• pp.293-300
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• 2006

This study was carried out to determine the effect of chemical fertilizer and two fermented types of pig slurry on the dry matter(DM) yield of three crops and chemical properties. The experiment design was a split plot with three replications. Main plots consist of three crops : $sorghum{\times}sudangrass$ hybrid('SS405'), sudangrass('Jumbo'), corn('DK501'). Sub plots consist of three treatments : chemical fertilizer (CF N-200, P-150, K-150 kg/ha), aerobic fermented pig slurry (APS 200kg N/ha), and aerobic fermented pig slurry treated with probiotics (APS+P 200 kg N/ha). Plant heights with three crops per sudangrass (380.3cm) was the longest (p<0.01). Dry matter yield of aerobic fermented pig slurry treated with probiotics was the highest the other treatments (p<0.01). Crude protein (CP) content were highest in $sorghum{\times}sudangrass$ hybrid than in the other crops. Cupper content(%) were highest in aerobic fermented pig slurry treated with probiotics than in the other treatments.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.2
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• pp.141-146
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• 2021

This study was evaluated to compare annual productivity and feed value of Italian ryegrass and summer forage crops at paddy field in middle region of Korea. Italian ryegrass (Kowinearly) was used as winter forage crop, and forage rice (Youngwoo) and barnyard millet (Jeju) were used as summer forage crops. Each crop was cultivated using the standard forage cultivation method. The plant height, dry matter yield, crude protein content, and total digestible nutrient content of Italian ryegrass were 90.6 cm, 7,681 kg/ha, 9.2%, and 63.8%, respectively, and it was no significant difference by summer forage crops (p>0.05). The plant height of summer forage crops was the higher in barnyard millet than in forage rice (p<0.05). The dry matter, crude protein, and total digestible nutrient yields of summer forage crops were the higher in forage rice than in barnyard millet (p<0.05). Also, the feed value of summer forage crops was higher in forage rice than in barnyard millet. In conclusion, the combination of Italian ryegrass-forage rice was the most effective cropping system for annual forage production with high-yield and high-feed value, and it was considered the combination of Italian ryegrass-barnyard millet was good cropping system for annual forage production through reducing labor and cultivating stable at paddy field in middle region of Korea.