• Journal of Forest and Environmental Science
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• v.36 no.2
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• pp.133-142
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• 2020

Soil physical and chemical properties at three layers such as top (0-10 cm), middle (10-20 cm) and bottom (20-30 cm) layers under three different vegetation types were studied. Soil samples were collected from Acacia forest, vegetable and fallow lands of Chittagong university campus, Chittagong, Bangladesh. Results showed that sand was the dominant soil particle followed by clay and silt fractions in all soil depths under different vegetation types. Soils of fallow land showed the highest values of bulk density while forest soils had the lowest values at three depths. Acacia forest soil having lowest values of dispersion ratio (DR) is less vulnerable while fallow soil with highest DR values is more vulnerable to soil erosion. The lower pH value at all soil layers in three ecosystems represented that soils under study are acidic in nature. Contents of organic matter, total nitrogen, exchangeable cations (Ca²⁺, Mg²⁺, K⁺ and Na⁺) and cation exchange capacity (CEC) were observed higher in Acacia forest soils compared to vegetable and fallow soils. Only soils of vegetable land had higher level of available phosphorus in three layers than that of other two land covers. The study also revealed that different soil properties were observed in three different vegetation types might be due to variation in vegetation and agronomic practices.

• 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.

• Journal of Animal Environmental Science
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• v.8 no.3
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• pp.135-144
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• 2002

A computer simulation was carried out to investigate the optimum capacity of liquid manure tank spreader which is used as a tractor attachment. Soil physical properties, such as soil moisture content, bulk density, soil hardness and soil types were measured in the 10 major rice production area for computer simulation. Mathematical model which include soil physical properties and vehicle factor was used for computer simulation. Most of the soil type of the investigated area was sandy clay loam. Soil moisture content ranged between 30 and 40% mostly. Soil bulk density was in the range of 1,500 to 1,700 kg/$m^3$. Soil hardness ranged between 1 to 18 $cm^2$. Soil hardness incorporate the effects of many soil physical properties such as soil moisture content, soil type and soil bulk density, and so the range of soil hardness is greater than any other physical properties. The capacity of liquid manure tank spreader was above 3,000 kg$_{f}$ for the most of the investigated areas, and mostly in the range of 4,000 to 6,000 $kg_f$ depending upon the slip. But for the soft soil area such as Andong and Asan, the tractor itself has mobility problem and shows no pulling force for some places. For this area, the capacity of liquid manure tank spreader ranged between 1,000 and 2,000 $kg_f$ mostly, so the capacity of liquid manure tank spreader should be designed as a small capacity trailer compared to the other area.mpared to the other area.

• Environmental Engineering Research
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• v.25 no.3
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• pp.409-417
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• 2020

Investigation was carried out to assess the effect of cement dust deposition on the physico-chemical properties of soil near some cement plants in Jaintia Hills, Meghalaya. Soil samples were collected and analysed and compared with the control site. Comparison of various soil physico-chemical parameters revealed that cement dust emanating from cement plants has changed the soil quality in the surrounding areas of cement plants. The normal soil pH in the area is generally acidic. However, due to the continuous deposition of cement dust soil pH was found slightly alkaline near the cement plants. The higher values of soil parameters such as electrical conductivity and bulk density were also noticed near the cement plants. However, lower values of water holding capacity, soil moisture content, soil organic carbon and total nitrogen content were found compared to the control sites. The effect of cement dust deposition on soil is more in areas nearer to the cement plants. At present the changes may not be so serious but if this trend continues, soil properties of a vast area around the cement plants are likely to change leading to multiple effects on flora, fauna and socio-economy of the area.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.4
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• pp.413-416
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• 2008

The cultivation of green manure crop is considered as a good management practice by increasing soil organic matter and fertility levels. This experiment was conducted to improve the soil environment under rice-based cropping system at paddy soil (fine loamy, mixed, nonacid, mesic, family of Aeric Fluventic Haplaquepts) in National Institute of Crop Science (NICS), Korea in 2006 to 2007. The variation of soil temperature in green manure plots was lower than without green manure (control) during spring season (April to May). The temperature variation of no tillage plot (broadcast before rice harvest) was the lowest among treatments. After green manure cropping, the soil bulk density and porosity ratio were improved at the top soil. The production of green manure was the highest athairy vetch and barley mixture plot by partial tillage. However, mixture treatment had no improvement on soil organic matter. After rice cropping with green manure application, soil quality was improved such as soil physical properties except mixture treatment. Therefore, we suggest that soil quality should be improved by green manure cultivation under rice-based cropping system.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1137-1143
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• 2011

Optimum soil management of chestnut orchards is important to ensure high quality and yields of chestnut. This study was conducted to evaluate soil and green leaf characteristics by establishment periods of chestnut (Castanea crenata Sieb. et. Zucc.) orchards in Sancheong-gun, Gyeongsangnam-do. Total 30 plots with the criteria of similar cultivation practices were chosen and classified into two establishment periods by over 20-year-old orchards (17 plots) and below 19-year-old orchards (13 plots). Soil bulk density was significantly higher (p<0.05) in over 20-year-old ($1.16g\;cm^{-3}$) than in below 19-year-old ($1.03g\;cm^{-3}$) plots. Soils in over 20-year-old plots were severely acidified with pH 4.56 compared to pH 4.73 in below 19-year-old plots. However, soil organic matter, total nitrogen, available phosphorus, and potassium were not significantly different (p>0.05) between both establishment periods. Leaf area, leaf mass, and nutrient (N, P, K, Ca, Mg) concentration of green leaves were also not significantly different (p>0.05) between both establishment periods. The results indicate that soil bulk density in chestnut orchards is dependent on the establishment periods, while soil chemical property and leaf nutrient concentration may be little influenced by the establishment periods.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.4
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• pp.190-194
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• 1982

The differences in soil productivity between the cut site and the fill site in a newly reclaimed land were compared with the experimental results conducted during 1978 to 1980 under soybean-barley and sweet potato-barley cropping systems. The results were summerized as follows; The bulk density of the cut site was near $1.5g/cm^3$ with the hardness above 23mm by Yamanaka method and that of the fill site was $1.3g/cm^3$ with the hardness of 14mm at the first year of reclaiming. The bulk densities and soil hardnesses asymptotically approched to $1.4g/cm^3$ and 19mm, respectively. The chemical productivity of the fill site was also significantly higher than that of the cut site. Differently from the bulk density and hardness, chemical compositions of the fill site maintained high untill the third year of cropping. The yields of soybean, sweet potato and barley from the cut site at the first year were very poor and, thereafter, were remarkably increased by 2 to 9 times at the third year of cropping while those from the fill site maintained high from the first year to the third year of cropping.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.234-237
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• 2011

This study was carried out to investigate the effect of soil covering materials such as rice bran, rice hull and saw dust on garlic growth through a field experiment in wintertime. Rice bran was the smallest in term of particle size, but it recorded the highest level of bulk density. The missing plant rate after winter season was relatively high, 59.3%, and that of soil covering materials stood at the low level of 10%. Other growth factors recorded the highest level during application of rice bran. In terms of chemical properties of soil-covering materials, rice bran recorded the highest level of 1.84, 2.34 and 0.16% in the content of N, P, and K, respectively. The subsoil temperature was higher by application of rice bran as compared to that of other materials which stood at the lowest temperature ($-9^{\circ}C$).

• Korean Journal of Environmental Agriculture
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• v.26 no.4
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• pp.279-285
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• 2007

Soil physical properties in organic farming apple orchard were evaluated in relation to conventional farming to better understand the effects of organic farming system on soil quality. Two adjacent apple orchards, matched by soil type, were chosen to ensure the same pedological conditions except management system. Soil samples were collected from middle of two adjacent trees along the tree line at two depths of 5-20 and 20-35 cm in September 2006. Contents of organic matter in organic farming soil were twice as much as those found in soil of conventional farming. The higher level of organic matter in organic farming soil was reflected through a consequent trend in improved soil physical properties. Organic farming produced greater aggregation in >2 mm size and increased aggregate stability. Bulk density was lower by 13% and hence porosity was higher in soils of organic farming as compared with conventional farming. Water holding capacity was significantly greater with organic farming by >17% over conventional farming. The capacity of organic farming to improve soil physical properties can be contributed to the regular application of relatively large amount of organic materials and the sustainable ground-cover managements, mulching with compost and cover crop cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1314-1319
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• 2011

This study was carried out to investigate the surface soil organic carbon fractions affecting by different land use types, including needle-leaf forest (FN), broad-leaf forest (FB), pasture, annual upland cropping land (upland), and paddy rice land (paddy). We chose seven regions across Korean inland, considering sea level altitude, and measured soil organic carbon content and physico-chemical properties such as bulk density at a depth of 0~15 cm using core samples in April for the each land use type. In addition, labile organic carbon fractions in soil including light fraction and hot water extractable carbon were investigated. From this study, organic carbon storage (Mg C per ha) in the upper 15-cm soils was highest in FB (37.8), and decreased in the order of pasture (29.1), FN (28.8), paddy (21.9), and upland crop (19.9). In forest, more than 20% of soil organic carbon existed as light fraction, the free organic matter. Hot-water extractable carbon contents of soils in five land use types were lower than 7% of their soil organic carbon content.