• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.1
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• pp.47-53
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• 2015

Storage root yield of sweetpotato was decreasing owing to continuous sweetpotato cropping, debasement of soil physical properties, increasing incidence of pest and disease. This study was conducted to evaluate the changes in physicochemical properties of the soil owing to subsoiling (subsoiling to 50 cm depth), and the effect on growth and yield of sweetpotato. The subsoiling treatments included subsoiling treated every year for two years, subsoiling in the first year, and no subsoiling control. The soil physical properties measured were bulk density, hardness, porosity, three phase. Bulk density, porosity, soild (%) of three phase were improved by subsoiling in topsoil and subsoil. Main vine length and vine yield in subsoiling soil were higher than those in no subsoiling soil, but those were not significantly different. Yield of marketable storage root in subsoiling soils treated every year for two years and treated in the first year was more increased 17% and 20% than no subsoiling soil, respectively. The number of marketable storage root per plant was also higher in subsoiling soils than no subsoiling soil, but it was not significantly different. Soluble solid contents and total free sugar contents of storage root of sweetpotato were not significantly different among the treatments. These results show that improving soil physical properties by subsoiling could promote high yield of marketable storage root in continuous sweetpotato cropping field.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.3
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• pp.254-261
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• 2012

To reduce the injury by continuous cropping of sweet potato (Ipomoea batatas (L.) Lam.), the farmer's plant and virus-free plant were cultivated with the density of $70{\times}25cm$ (June 10, 2011) in continuous cropping soil (CCS) and subsoiling reversion soil (SRS). Fertilizer was applied at the rates of 55-63-156 $kg\;ha^{-1}$ ($N-P_2O_5-K_2O$) and 10 $ton\;ha^{-1}$ of cattle manure in CCS, and it was applied the 50% increased cattle manure compost and nitrogen in DRS. Symptoms of viral infection were revealed in the farmer's plant at 30 days after planting, but there were no symptoms in virus-free plant. The yield of virus-free plant was more increased 15% and 10.5% than that of farmer's plant in DRS and CCS, respectively. The yield of sweetpotato in SRS was more increased 8.8% and 3.2% in farmer's plant and virus-free plant compared to CCS, respectively. In DRS, the rate of marketable tuber of virus-free plant was increased by 80% compared to the farmer's plant (60.1%). The virus-free plant was produced the tuber with more brilliant peel color and well-formed shape compared to the farmer's plant. The increased yield of virus-free plant and in SRS soil condition showed a positive relationship (p=0.05) with the number of leaf per plant at 30 days and the number of branch per plant at 120 days after planting. The results showed that the early growth after planting was very important for the development of storage root. Therefore, the deep-subsoil reversion and cultivation of virus-free plant could be reduced the injury by continuous cropping of sweet potato, and increased farm income.

• Korean Journal of Weed Science
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• v.15 no.4
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• pp.298-304
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• 1995

This study was carried out to make the most of them as the fundamental data for reasonable weed control when population of weeds was observed in the alternated fields of lowland and upland. The annual and the perennial paddy weeds in the continuous paddy rice field remarkably decreased when compared to that in the alternated field of paddy rice and soybean. The longer was the duration of upland field condition, the less was the population of lowland weeds and the more was the population of upland weeds. Biennial weeds in the contiuous paddy rice field were less than that in the rotated field of paddy rice and soybean, and this tendency was clear in Alopecurus aequalis Sobol. In the continuous cropping of paddy rice, population of biennial weeds in the culverted field was higher than that in the unculverted one, but in the continuous cropping of soybean this tendency was vice versa.

• Korean Journal of Environmental Agriculture
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• v.28 no.1
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• pp.9-14
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• 2009

Applying livestock manure compost to soil can enhance soil fertility and crop productivity. However, little information is available on the effect of continuous application of manure compost on crop growth in Korea. The object of this study was to investigate the residual and continuous application effect of chicken manure compost on chinese cabbage yield and soil chemical properties. The experiment was conducted in the pot ($0.5\;m^2$) without bottom buried in the soil and set up in a completely randomized design with three replication. The treatment consists of chemical fertilizer with nitrogen (NPK, $N-P_{2}O_{5}-K_{2}O$ 320-78-198 kg/ha) and without nitrogen (PK, $N-P_{2}O_{5}-K_{2}O$ 0-78-198 kg/ha), and chicken manure compost at a rate corresponding to 320 (COM1) and 640 (COM2) kg N/ha. This experiment was carried out for three cropping seasons with chinese cabbage. Chemical fertilizer, NPK and PK, was applied every cropping season. In the first cropping season, compost was applied in nine pots (COM-A). In the second cropping season, compost was applied in the six pots of COM-A (COM-AA) and in three pots of COM-A compost was not applied (COM-AN). In next cropping season, compost was applied in the three pots of COM-AA (COM-AAA) and in the other three pots of COM-AA compost was not applied (COM-AAN). COM-AN pots remained without compost application in the third cropping season (COM-ANN). Yields of chinese cabbage of COM1-AAA and COM2-AAA were reached 78 and 96% as compared with NPK, and nitrogen utilization rate was about 85% (COM1-AAA) and 97% (COM2-AAA) as compared with NPK Residual N uptake rates during the second and third cropping season after compost application at the first cropping season were 49.7 (COM1-AN) and 35.6% (COM1-ANN) in COM1, and 56.9 (COM2-AN) and 37.4% (COM2-ANN) in COM2 compared with NPK treatment After three cropping seasons, soil pH and contents of available phosphorus, exchangeable potassium and soil organic matter were increased with continuous application of chicken manure compost.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.2
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• pp.97-104
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• 2005

This experiment was conducted to introduce strip croppings fur decreasing the damage of the continuous com cultivation at the experimental field of Grassland and Forage Crops division, National Livestock Research Institute from 1999 to 2000. Introduced mps for strip cropping to the continuously com cultivated field were red clover (RC), alfalfa(AL), and mixture of grass md legume. Fall panicum(FP), which is one of warm season's weeds was focused on its emerged quantity in com field changed by the level of soil water content and degree of the continuous corn cultivation. The ranges of yearly gained forage fresh yields including weeds like mainly FP were 119.4 ${\~}$ 169.6 in the continuous cultivation with com and rye and 64.9 ${\~}$ 83.3 ton / ha in the corn mono-cropping. Meanwhile, the percentages of pure com in continuous com cultivation plot were only $31-38\%$. This was for the mainly emergence of FP in the continuously com cultivated field. The ranges of average fresh yield of emerging FP were 45.6${\~}$63.4 ton/ ha in the continuously com cultivated field which were over the ranges of yields of rye, 28.2 ${\~}$ 41.6 ton/ ha. The dry matter yields of red clover, alfalfa and mixture with grass and legume introduced for strip cropping were 10.2, 10.6 and 10.6 ton / ha, respectively and these were about the 1/4 average fresh com yield. After strip cropping of red clover, alfalfa and mixture with grass and legume, the yields of corn increased to 56, 82, 88 and 79 ton / ha, respectively and com yield was much better in the alfalfa strip cropping.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.1
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• pp.49-56
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• 1993

The net flux of global green house gases such as carbon dioxide($CO_2$), methane($CH_4$), and nitrous oxide($N_2O$) emitted from the rotation of paddy-upland soil during growing sesaon under different cropping system was determined. The results obtained were summarized as follows : 1. The net flux of $CO_2$ during the growing season was the highest from continuous cultivation of rice but the lowest from rotation cultivation of rice-soybean. Under the different cropping system the highst emission was from soil of continuous cultivation of rice, but the lowest from converted system. 2. The net emission of methane was the highest from the sold of continuous cultivation of rice, but the flux was remarkably decreased by differing the cropping system. 3. $N_2O$ was emitted greatly from the every two year rotation of potato-chinese cabbage and the next rank was from continuous cultivation of rice, but was decreased notably from rotation cultivation of rice-soybean and potato-chinese cabbage under rotation of paddy-upland cropping system. 4. The ratio of oxygen and carbon dioxide in the soil air was much different with glowing season, the ratio was varied with 4~10 percents for oxygen and 1~22 percents for carbon dioxide. The ratio of carbon dioxide was dozens or hundreds times to that of air, and the variation was very high also. 5. The emission of global green house gases such as carbon dioxide, methane and nitrous oxide was affected by the moisture, temperature and nutrients of soils and the growth period of crops.

• Korean Journal of Plant Resources
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• v.28 no.2
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• pp.263-270
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• 2015

To reduce the injury by continuous cropping system of tomato cultivation, green manure crops (GMCs) such as hairy vetch and rye were applied, Nutrient contributions of N, P₂O₅, K₂O, CaO, and MgO in hairy vetch were 26.2, 5.8, 10.2, 6.6, and 1.5 ㎏/10a, respectively. Nutrient contributions of N, P₂O₅, K₂O, CaO, and MgO in rye were 9.1, 4.2, 11.8, 3.8, and 3.1 ㎏/10a, respectively. After incorporation of GMCs into soil, bulk density in soil with GMCs was lower than that in soil without GMCs (control). In soil after incorporation of GMCs, pH was not different in all treatment conditions, and ranged from 6.37~6.52. EC in soil after incorporation of GMCs was lower than that in soil without GMCs. The OM, T-N, and avail. P₂O₅ contents in soil with GMCs were higher than those in soil without GMCs. The tomato growths were increased in the rotational cropping system (RCS) as compared to continuous cropping system (control and without NPK). Also the density of Pseudomonas corrugata in soil with GMCs was lower than that in soil without GMCs (control). This study suggest that the RCS using GMCs showed lower disease outbreak density in soil for tomato cultivation as compared to RCS without GMCs. Especially, the GMCs was good effect for reduction of continuous cropping injury of tomato.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.3
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• pp.205-214
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• 1989

The present experiment was conducted to investigate effects of soil conditioner applied on continuous cropping fields of red pepper from 1985 to 1986 in Imsil, Chunbuk province. 1. The ratios of bacteria/fungi (B/F) and actinomycetes/fungi (A/F) in the soils of continuous cultivation were increased with application of phytotoxin decomposers such as deep tillage (De), compost (Co), magnesium lime (Mg), gypsum silicate, and De + Co + Mg. 2. Degradation of phytotoxin (p-hydrohylenyons aeid) in the continuous soils was promoted with application of De, Co, Mg, gypsum, silicate and De + Co + Mg resulting in yield increase. 3. The infection rate plant by phytophthora were decreased with deep tillage and application of compost and magnesium lime and caused the increase of yield (22%) due to the increase of fruit per hill.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.174-177
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• 2011

Green manure crops play an important role in organic farming. Field experiment was conducted at paddy soil (fine loamy, mixed, nonacid, mesic family of Aeric Fluvaquentic Endoquepts) in 2008/2009 to 2009/2010 at the National Institute of Crop Science (NICS), RDA, Suwon, Gyeonggi province, Korea. This experiment was carried out to evaluate the biomass of hairy vetch (Vicia villosa) and growth of rice (Oryza sativa) by different seeding rates. Seeding rates of hairy vetch consisted of 30, 60, and 90 kg $ha^{-1}$ by broadcasting before rice harvesting. The biomass and nitrogen production of hairy vetch were not significantly different between 60 kg $ha^{-1}$ and 90 kg $ha^{-1}$ of seedinq rates. Also, rice yield was not significantly different between seeding rate 60 kg $ha^{-1}$ of hairy vetch and conventional practice for two years. Therefore, we suggested that seeding rate of hairy vetch should be reduced by continuous cropping and incorporation of hairy vetch under rice-based cropping system.

• Korean Journal of Plant Resources
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• v.28 no.2
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• pp.271-278
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• 2015

This experiment was carried out to evaluate the effects of green manure crops on the changes of chemical properties and microorganisms in soil of continuous ginger cultivation. The biomass and nitrogen absorption of green manure crop were the highest in crimson clover. After cropping, soil phosphate content was the lowest in orchard grass, however, T-N content was the highest of hairy vetch > crimson clover > orchard grass. Also real-time PCR analysis was conducted to measure density of Pythium zingiberum in soil of before and after incorporation of green manure crop. Density of P. zingiberum was the lowest of all the green manures. In this results are summarized that green manure cropping reduced salt accumulation and density of P. zingiberum in continuous ginger cultivation.