• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.572-577
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• 2010

Field monitoring was performed to evaluate the soil chemical properties of 31 sweet persimmon orchard soil samples every two months from April to October in 2008 at Gyeongnam Province. Soil chemical properties such as pH, organic matter, available phosphate, exchangeable potassium, exchangeable calcium, exchangeable magnesium, exchangeable sodium, ammonium nitrogen, and nitrate nitrogen were analyzed. The soil chemical properties of both top soil, and subsoil showed that soil pH was significantly increased whereas ammonium nitrogen, and nitrate nitrogen were significantly decreased. The insufficient levels of nutrients in top soil, and subsoil were higher in 69.4%, and 84.7% for pH, 63.7%, and 84.7% for organic matter compared to optimum range. Meanwhile, the excessive levels of available phosphate showed 70.2% in top soil, and 46.8% in subsoil compared to optimum range. The experimental results showed that the optimum fertilization based on soil testing was the most important thing in soil nutrients management for sweet persimmon.

• 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.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.3
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• pp.205-212
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• 2014

Chronological changes of soil organic carbon (SOC) must be prepared by IPCC guidelines for national greenhouse gas inventories. IPCC suggested default reference SOC stocks for mineral soils and relative stock factors for different management activities where country own factors were not prepared. 3.4 million data were downloaded from agricultural soil information system and analyzed to get chronological changes of SOC for some counties and for land use in Korea. SOC content of orchard soil was higher than the other soils but chronological SOC changes of all land use had no tendency in differences with high standard deviation. SOC contents of counties depended on their own management activities and chronological SOC changes of districts also had no tendency in differences. Thus, Korea should survey the official records and relative stock factors on management activities such as land use, tillage and input of organic matter to calculate SOC stocks correctly. Otherwise, Korea should establish a model for predicting SOC by analyzing selected representative fields and by calculating SOC differences from comparing management activities of lands with those of representative fields.

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.667-676
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• 2022

The soil physical and chemical properties are the main factors that influence plant productivity and soil fertility. Since 1999, South Korea has been conducting a survey on changes in the agricultural environment survey every four years. The purpose of the present study is to monitor the physical and chemical properties of soil in Chungcheongbuk-do. Soil samples were collected from the exact sites of the aforementioned environment survey, and land use and cultivated crops were also investigated. From a Pearson correlation analysis, it was found that the total carbon contents were most negatively affected by the soil depth. The bulk density of soil increased up to a depth of 40 cm but decreased to a depth of 60 cm. The porosity and moisture of soil generally decreased, but the porosity increased at a depth of 50 - 60 cm. Chemical properties of soil gradually decreased with an increase of the soil depth from 0 to 70 cm, but little change was observed in soil pH with soil depth. In addition, the organic matter contents of the soil at a depth of 30 cm or more were below the optimal range. The soil of Chungcheongbuk-do thus requires organic matter application as a whole, and correction of items that are partially out of the optimal range is necessary.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.357-360
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• 2005

Soil loss is widely recognized as a threat to farm livelihoods and ecosystem integrity worldwide. Soil loss prediction models can help address long-range land management planning under natural and agricultural conditions. Even though it is hard to find a model that considers all forms of erosion, some models were developed specifically to aid conservation planners in identifying areas where introducing soil conservation measures will have the most impact on reducing soil loss. Revised Universal Soil Loss Equation (RUSLE) computes the average annual erosion expected on hillslopes by multiplying several factors together: rainfall erosivity (R), soil erodibility (K), slope length and steepness (LS), cover management (C), and support practice (P). The value of these factors is determined from field and laboratory experiments. This study calculated soil erosion using GIS-based RUSLE model in Imha basin and examined soil erosion source area using SPOT 5 high-resolution satellite image and land cover map. As a result of analysis, dry field showed high-density soil erosion area and we could easily investigate source area using satellite image. Also we could examine the suitability of soil erosion area applying field survey method in common areas (dry field & orchard area) that are difficult to confirm soil erosion source area using satellite image.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.5
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• pp.279-284
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• 2008

This study was performed to investigate effect of different soil managements on physical properties and microbial activities in volcanic ash citrus orchard soil. Experiment plots had managed to control weeds on soil for 4 years with clean cultivation (CCM) used with herbicide, natural sod cultivation (NSCM), kentucky blue grass sod cultivation (KBG). Soil samples were taken on October, in both 1998 and 2000 from 3 experimental plots. In NSCM, Soil hardness was lower at 11.8 mm than in CCM. And water stable Aggregation coefficient(>0.5 mm) was high at 26.7% compared with CCM. Soil bulk density and porosity showed no significant among the treatments. Soil acid phosphatase was high in sod cultivation plots and the amount of microbial biomass C was about twice higher at $525.4mg\;kg^{-1}$ in KBG than in CCM. Conclusionally, Sod cultivation improved soil physical properties such as aggregation, hardness and increased microbial activities compared with clean cultivation in citrus orchard soil. Soil total PLFA, acid phosphatase, and microbial biomass C contents were investigated on May in nonvolcanic ash citrus soil. Soil samples were collected at 5 sites each; convention cultivation grown with herbicide, natural sod cultivation grown with 1/2 chemicals, organic cultivation. That sites have been managed for 5 years over. PLFA contents were two times higher at $112.2n\;mol\;g^{-1}$ in organic cultivation than in convention cultivation. According to the PLFA indicator, Gram negative bacteria and actinomycetes in organic cultivation were high compared with convention cultivation, which were at 15.1%, 6.6%, respectively. Soil microbial biomass C contents was about twice higher in organic cultivation than in convention cultivation. Soil acid phosphatase was high at 17.6% in organic cultivation compared with convention cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.2
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• pp.61-66
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• 1979

This experiment was conducted to find out the simple and economical method to improve physical properties of the soil that was very poor for the establishment of orchard. Jeonnam clay loam soils distributed mainly on rolling and hill side slope, were treated with the explosion of two kinds of dynamite at the depth of 1 m. The change of physical properties was investigated vertically and horizontally after soil profile had settled to some extent. The results were summarized as : 1. The original soil was very high in bulk density and soil hardness. Total porosity and aeration porosities were lower than critical level providing root elongation. It was more apparent in the subsoil than in the surface soil. 2. It was recognized that soil mass destruction and cracking by dynamite explosion decreased soil bulk density and soil hardness and increased porosity, especially non-capillary pores. 3. Effective radius of the improved physical properties by explosion with two dynamites was 100cm at 60cm depth and 30cm at 80cm depth. But with the use of three dynamites it was 100cm at 80cm depth. 4. It was thought that soil mass destruction and cracking caused by explosion was uneven in the two dynamites, and three dynamites was more effective to improve physical properties evenly. 5. With the use of two dynamites, Ammonium explosive was superior to gelatin dynamite.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.4
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• pp.375-380
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• 1984

A pot experiment was conducted to learn the effect of non-compounded and compounded (with super phosphate) liquid fertilizers made of amino acid fermentation by product and the time of their application on the emergences and yield of orchard grass. Results obtained as follows; 1. The Application of the liquid fertilizers, on seeding day of the orchard grass raised soil pH and salt concentration more than the application on the days before seeding and decreased the number of sprouts of the grass which also lead to a lower yield of the grass compared with the latter. 2. Liquid compound fertilizer, however, tended to reduce the harmful effect on sprouting orchard grass compared with non-compounded liquid fetilizer, particulary in soil of on-lime applied. 3. The application of liquid and liquid compound fetilizers on somewhat acidic bare land a quite ahead of seeding or transplanting crops may not only reduce the effect of the fertilizers, provided the land is free from washing by rain or irrigation water, but also provide better conditions for sprouting and early growth of plant seedings than the use at the pre-seeding or pro-transplanting time.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.2
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• pp.161-166
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• 1984

The Cheju citrus orchards have been chemically fertilized with both phosphates high in Ca and Mg contents and potassium. The amount of chemical fertilizers consumed per unit area of cultivated land and the ratios of $P_2O_5$ and $K_2O$ to N in chemical fertilizers applied were much higher in the Cheju Island than those of the Korean mainland. These trends were particularly prominant in Southern Cheju where 70% of the Cheju citrus orchards are located. As the result of heavy applications of phosphate fertilizers, the available phosphorus of citrus orchard soils increased with increasing number of years under cultivation. The available phosphorus of sub-soil increased slightly with the number of years under cultivation compared to that of surface soil. Base saturation and pH increased with the number of years under cultivation, inasmuch as exchangeable bases such as Ca, Mg and K increased predominantly, but the cation exchange capacity did not vary in the citrus orchard soils.

• Korean Journal of Environmental Agriculture
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• v.29 no.3
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• pp.287-292
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• 2010

We aimed to investigate the responses of soil organisms to cover plants and to provide information for the selection of proper plant species. We studied the effects of 7 cover plants, including rye, oat, rattail fescue, Chinese milk vetch, red clover, crimson clover, and hairy vetch, on soil organisms in an apple orchard. An increase in the microbial phospholipid fatty acids (PLFA) and in the number of nematodes and microarthropods in the soil under the cover plants reflects elevated activities of soil organisms. A decrease in the level of some marker PLFA, which is an indicator of environmental stress, suggests that cover plants provide favorable environments for soil organisms. The population of fungi and animals that feed on fungi increased in the soil surface under red clover. The population density of nematodes and mites increased in the soil surface under rattail fescue, and that of mites and omnivorous nematodes increased in the soil surface under Chinese milk vetch. The level of microbial PLFA in the soil surfaces under the tested cover plants was higher than that under clean culture system. These results suggest that proper selection of the cover plants can facilitate the creation of favorable environments for soil organisms.