• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.963-974
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• 2015

This study was conducted to determine the effects of organic vegetable cultivation on the soil physical properties in 33 farmlands under plastic greenhouse in Korea. We were investigated 5~8 farms per organic vegetable crops during the period from August to November 2014. The main cultivated vegetables were leafy lettuce (Lactuca sativa L.), Perilla leaves (Perilla frutescens var. Japonica Hara), cucumber (Cucumis sativus L.), strawberry (Fragaria ananassa L.) and tomato (Lycopersicon spp.). We have analyzed soil physical properties. The measured soil physical parameters were soil plough layer, soil hardness, penetration resistance, three soil phase, bulk density and Porosity. The measurement of the soil plough layer, soil hardness and penetration resistance were carried out direct in the fields, and the samples for other parameters were taken using the soil core method with approximately 20 mm diameter core collected from each organic vegetable field. Soil plough layer was average 36 cm and ranged between 30 and 50 cm, and slightly different depending on the sorts of vegetable cultivation. The soil hardness was $0.17{\pm}0.15{\sim}1.34{\pm}1.02$ in the topsoil, $0.55{\pm}0.34{\sim}1.15{\pm}0.62$ in the subsoil. It was not different between topsoil and subsoil, but showed a statistically significant difference between the leafy and fruit vegetables. Penetrometer resistance is one of the important soil physical properties that can determine both root elongation and yield. The increase in density under leafy vegetables resulted in a higher soil penetrometer resistance. Soil is a three-component system comprised of solid, liquid, and gas phases distributed in a complex geometry that creates large solidliquid, liquid-gas, and gas-solid interfacial areas. The three soil phases were dynamic and typically changed in organic vegetable soils under greenhouse. Porosity was characterized as range of $54.2{\pm}2.2{\sim}60.3{\pm}2.4%$. Most measured soils have bulk densities between 1.0 and $1.6gcm^{-3}$. To summarize the above results, Soil plough layer has been deepened in organic vegetable cultivation soils. Solid hardness (the hardness of the soil) and bulk density (suitable for the soil unit mass) have been lowered. Porosity (soil spatial content) was high such as a well known in organic farmlands. Important changes were observed in the physical properties according to the different vegetable cultivation. We have demonstrated that the physical properties of organic cultivated soils under plastic greenhouse were improved in the results of this study.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.722-726
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• 2011

The management standard on soil conditions in 'Fuji' apple to produce high quality fruit were not yet made. Therefore, this study was carried out to investigate the optimum soil environmental conditions of ten contents on production of high quality fruit in 'Fuji' apple. The soil and fruit characteristics were analyzed at total 60 orchards in major apple producing areas such as Chungju, Moonkyeung, yeongju, andong, yeosan and yeongcheon (10 orchards an area). The soil environmental factors affected fruit weight was highest relative contribution in saturated hydraulic conductivity of 36.5%. The bulk density and soil pH were low as relative contribution. The fruit weight was influenced by soil physical properties more than soil chemical properties. The soil environmental factors affected sugar content were hydraulic conductivity of 28.3% and organic matter content of 18.2%. The cultivation layer depth and soil pH were low as relative contribution. The fruit coloring was highest relative contribution in saturated hydraulic conductivity 55.9%. while soil pH, cation and soil texture were low. Fruit coloring was high influenced over 70% by soil physical properties. Finally, relative contribution on fruit quality related with sugar content, fruit weight, and coloring were high influenced by saturated hydraulic conductivity of 21.% and organic matter content of 18.7% but bulk density and cultivation layer depth were low relative contribution. The fruit growth and saturated hydraulic conductivity in 'Fuji' apple were very closely related. Therefore, orchard soil management to produce high quality fruit was very importance drainage management and organic matter application. We concluded that scientific soil management is possible by qualifiable of soil management factors.

• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.863-870
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• 2010

We investigated geographical condition and soil characteristic of ginseng cultivation site. At all sites, crown density adjusted by 80%. and Air and soil temperature were also measured. The geographical condition vary ato all sites. and soil shows similar characteristics with typical forest soil of Korea. The results shows the Air temperature needs to be higher than $15^{\circ}C$ for seed budding at April When soil temperature reach at 8, leaf of foest ginseng starts to bud. A forest ginseng is influenced by forest type, planting type and budding rates. In the case of a seedling planting, an seeding emergence rate is high, but the rate is decreased rapidly after three years On the other hand, direct seeding shows lower seedling emergence rate, but survival rate is higher than seedling-planting.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.3
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• pp.187-192
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• 2013

This study was carried out to investigate the incorporation effect of green manure crops (GMC) such as the hairy vetch on improvement of soil environment in reclaimed land during silage corn cultivation over the past two years. Plots consisted of conventional fertilization (CF) and incorporation of GMC were divided by addition rate of nitrogen fertilizer (100 kg $ha^{-1}$) with 30 - 100% of non nitrogen fertilization (NNF). Soil physico-chemical properties and growth and yield potential of silage corn were examined. The tested soils showed strong alkali and saline properties with low contents of organic matter and available phosphate while contents of exchangeable sodium and magnesium were high. Soil salinity increased during cultivation of summer crop. However, corn was not affected by salt content. The fresh weight of GMC at incorporation time was 18,345 kg $ha^{-1}$. Content of total nitrogen was 3.09% and the C/N ratio was 12.8 at incorporation time. Fresh and dry matter yield of silage corn were higher in the order of N30% reduction, CF, N50% reduction, N70% reduction, N100% reduction and NNF. Fresh and dry matter yield potential of silage corn for N30% reduction were comparable to those of CF. Bulk density of the soil decreased with incorporation of GMC, while porosity was increased. The soil pH decreased while content of exchangeable calcium, available phosphate, and organic matter increased. Also contents of exchangeable sodium and potassium decreased with incorporation of GMC. The data indicate that incorporation of hairy vetch can improve soil physical and chemical properties and reduce nitrogen fertilizer application especially for alkali saline reclaimed soil such as Saemangeum reclaimed land.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.101-101
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• 2022

In recent years, due to climate change, the livestock industry has become more interested in the production of forage crops. In Korea, more than 74% of forage crops are cultivated in winter rice fields. In particular, Italian ryegrass (IRG) is depends on imports for more than 70% of its seeds. In generally, the IRG rapeseed cultivation method involves sowing from early October to mid-October by drill sowing seeding or spot seedling. However, the sowing period is delayed due to frequent rainfall during. And, same period require a lot of seeds. However, raising seedlings and transplanted IRG will overcome weather conditions and reduce the amount of seeds. This study was intended to be applied to the domestic IRG seed industry in the future through growth and quantity evaluation according to transplant time and planting density for the production of good quality IRG seeds in rice paddy fields. In this study, transplanting time (October 20, October 30, November 10) and planting density (50, 70, and 80) were cultivated at the National Institute of Crop Science in 2021. The amount of fertilizer applied was adjusted to (N-P₂O₅-K₂O) 4.5-12-12 (kg/10a), and then 2.2(kg/10a) of nitrogen was added each year. For the growth survey, leaf area, canopy coverage, plant length, and seed yield were investigated. Along with the transplanting time, the plant length was higher on October 20 than on October 30 and November 10. On the other hand, leaf area index changes differed depending on the transplanting time and planting density, and were particularly high on October 20, 80 density and 70 density, but similar on October 30 and November 10. 1000 seed weight showed no difference with transplanting time and planting density. On the other hand, the seed yield was 215(kg/10a) for 80 density on October 20, 211(kg/10a) for 70 density, 118(kg/10a) for 50 density, and 80 density for October 30 and November 10. and 70 density did not differ. On the other hand, the 50 density on October 30 and November 10 were 164(kg/10a) and 147(kg/10a) respectively. As can be seen from this study, the earlier the transplant, the higher the seed yield. However, the 50 density was reduced in yield compared to the 70 density and 80 density.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.375-380
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• 2016

The use of polyethylene film has a problem such as increasing rural environmental contamination, collection costs and farmers' workload. The objective of this study was to evaluate bio-degradable films in terms of yield of maize and soil environment. Treatments were bio-degradable film A (BDF A), bio-degradable film B (BDF B), high density polyethylene (HDPE), and non-mulched (NM) soil. Daily mean values of soil temperature (10 cm depth) under BDF A, BDF B, and HDPE were higher than in NM soil by 2.2, 2.8, $3.1^{\circ}C$ respectively. In the mulching cultivation of maize, bio-degradable film began to degrade from 50~60days after the planting. The degradation was much progressed in the harvest time and almost decomposed in the following spring. The weight of ear of maize was not shown significantly by mulching treatments. There were little changes of soil chemical properties for the bio-degradable film mulching. After using bio-degradable films, the contents of biomass-C and dehydrogenase activity increased from 92 to $137{\sim}147mg\;kg^{-1}$, and from 87 to $123{\sim}168mg\;kg^{-1}$ respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.2
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• pp.156-159
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• 2001

The experiment was carried out to investigate the productivity of freshwater rotifer, Brachionus calyciflorus and marine rotifer, B. rotundiformis at various temperatures, initial inoculation and pH in a 5 L semi-continuous high density culture. Rotifers were fed by commercial condensed freshwater Chlorella. When pH was not controlled, average daily productions of freshwater and marine rotifers increased with temperature. The highest production, $44\times10^6$ rotifers, was achieved of B. calyciflorus at $32^{\circ}C$ and the possible production lasting period of B. calyciflorus was shorter than that of B. rotundiformis. Under the adjustment of pH at 7, the possible production lasting periods of B. calyciflorus and B. rotundiformis inoculated with 5,000 inds./mL were longer than those of rotifers inoculated with 10,000 inds./mL, and the daily production rate of the former was higher than that of the latter. The results from this study indicated that optimum density of the initial inoculation for the cultivation of B. calyciflorus and B. rotundiformis was 5,000 inds,/mL under the controlled conditions of pH 7 and at $32^{\circ}C$ in a semi-continuous high density culture, in terms of production rate and food cost aspects.

• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.292-298
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• 1997

These studies were conducted to verify the effect of the supplementary lighting by reflective film mulching and its establishment in the north side of greenhouse on the utility of light at tomato by means of investigating changes of leaf temperatures, stomatal features, transpiration rates and photosynthetic rates. Stomatal density of leaves were high in the reflective film mulching but sizes of stomata were not different. As the osmotic potential in rooting zone was low, the stomatal resistance was high, transpiration rate was low, and leaf temperature was increased by 40.62$^{\circ}C$. And also in the block of reflective film mulching photosynthetic rates were decreased hut chlorophyll contents were not different. Especially, there is an effect of controlling greenhouse whiteflies by treatment of reflective film mulching. It is thought that the reason of high quality or increasing yield at several crops by supplementary lighting, such as reflective film mulching, would be caused by influences of absorption and distribution of nutrients through high transpiration rate and photosynthesis which resulted from increase of stomata.

• Journal of the Korean Wood Science and Technology
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• v.39 no.1
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• pp.68-74
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• 2011

Cauliflower mushroom ($Sparassis$ $crispa$) is being cultivated as a functional mushroom since the mushroom contains larger amount of ${\beta}$-glucan than other edible or medicinal mushrooms. In this study, as a fundamental study for the cultivation process of cauliflower mushroom, we assayed the mycelial growth and the productivity of the mushroom cultivated on the sawdust-based medium made of larch ($Larix$ $kaempferi$) by 4 kinds of medium densities and 6 kinds of particle sizes. Low densities of sawdust-based media (0.68~0.72 g/$cm^3$) showed high variations in mycelial growth at early stage on sawdust-based medium. The coefficient of variance for the mycelial growth decreased from higher than 40% at the 3rd week to lower than 10% at the 7th week. High density of sawdust-based medium (0.80 g/$cm^3$) showed relatively lower variation in the mycelial growth at early stage with less than 30% of coefficient of variance, the high density of sawdust-based medium was thought to be quite stable compared to the lower densities of sawdust-based medium. From the viewpoint of mushroom productivity especially for the goods (excluding bottom of fruiting body), 0.76 g/$cm^3$ was better than any other densities; the return rates of fruiting body from each medium were 12.2, 13.6, 13.1, and 12.0% for 0.80, 0.76, 0.72, and 0.68 g/$cm^3$, respectively. By the way, it took about 40 days for harvesting from primordium formation with the sawdust-based medium excluded the particles less than 1 mm, while it took about 70 days with the medium including the particles less than 1 mm. The yield from the sawdust-based medium with the particles less than 1 mm was also quite less than any other sawdust-based medium especially for the goods. Therefore, we recommend that the sawdust-based medium with larch for the cultivation of cauliflower mushroom be prepared as 0.76 g/$cm^3$ in medium density with excluding the particles less than 1 mm.

• Mycobiology
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• v.31 no.2
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• pp.105-112
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• 2003

Sclerotia of Grifola umbellata were cultivated by two methods such as burying and root inoculation methods. The sclerotia of G. umbellata produced by the burying method were $6.0{\sim}6.8{\times}3.4{\sim}4.6{\times}1.8{\sim}1.9cm$(Width$\times$Length$\times$Thickness) in size and $17.3{\sim}19.6g$ in weight, respectively. Their increase rate was $1.10{\times}1.12$ times. On the other hand, the sclerotia cultivated by the root inoculation method were $18.3{\sim}31.5{\times}12.5{\sim}26.4{\times}3.1{\sim}3.7cm(W{\times}L{\times}T)$ in size and $219.1{\sim}576.6g$ in weight, respectively. Their growth increment was $11.18{\sim}39.77$ times. The rhizomorphs of Armillaria mellea were developed with a high density under fallen leaves layer covering cultivation site, and distributed mainly between soil surface and soil depth of about 10 cm as well as colonized prominently on the inoculated wood logs. Fungal interaction between G. umbellata and A. mellea were observed mainly in the stage of white sclerotium of G. umbellata. The sclerotia of G. umbellata which were developed newly and harvested in the root inoculation method were twined with root hairs of host tree and rhizomorphs of A. mellea. The sclerotia of G. umbellata decomposing root hairs of host tree were confirmed through SEM examination. Physiochemical characteristics of soil in all cultivation sites had no significant differences. Soil pH were in the range of pH $3.98{\sim}4.40$. Organic matters were the range of $17.97{\sim}23.86%$ and moisture contents of soil were $12.00{\sim}18.20%$. Soil temperatures showed $12.9{\sim}13.8^{\circ}C$ in November and $22.0{\sim}23.9^{\circ}C$ in August, respectively. In conclusion, the root inoculation method seems to be a practical method for cultivating sclerotia of G. umbellata due to its many advantages such as simplicity of inoculation process, shortening of cultivation periods and facility of harvest.