• Korean Journal of Soil Science and Fertilizer
• /
• v.32 no.2
• /
• pp.123-131
• /
• 1999

To get the basic information for the improvement of the optimum levels of upland soil fertility and fertilizer application, the soil samples in two hundred fifteen site were collected from the major condiment vegetable cultivation areas such as red pepper, garlic and onion fields. Physico-chemical properties of the soil samples were investigated. Soil texture distribution of soil samples in red pepper, garlic and onion cultivation areas was in order of loam (L), sandy loam (SL), silt loam (SiL) and clay loam (CL) (35.4, 31.6, 14.9 and 7.0%, respectively). The average pH of soil in garlic and onion cultivation areas were over pH 6.0, whereas in red pepper was under pH 5.5. The frequency distribution of soil pH in total sampling sites were 58.7% in under pH 6.0 and 21.4% in below pH 5.0, in contrast to 10.3% in over pH 7.0. The organic matter contents were in the range of $20{\sim}30g\;kg^{-1}$, and the onion field soils was a little higher than those in red pepper or garlic. The available phosphate contents were in the range of $719{\sim}746mg\;kg^{-1}$ and were not different among in red pepper, garlic and onion. The frequency distribution of available phosphate in total sampling sites were found 62.8% of above $600mg\;kg^{-1}$, which was over the standard level for upland soil improvement, and then 22.3% was exceeded $1,000mg\;kg^{-1}$, especially. In the exchangeable cations, the K and Ca contents in garlic (1.27 and $9.11cmol\;kg^{-1}$) and onion (1.20 and $8.39cmol\;kg^{-1}$) were higher than in red pepper (0.96 and $5.87cmol\;kg^{-1}$), respectively. The Mg contents in garlic field soils ($2.17cmol\;kg^{-1}$) were higher than those in red pepper and onion (1.51 and $1.80cmol\;kg^{-1}$). This exchangeable K, Ca and Mg contents were higher than the standard level for upland soil improvement. The contents of microelement were ranged in $54.3{\sim}60.1mg\;kg^{-1}$ for Fe, $31.3{\sim}42.3mg\;kg^{-1}$ for Mn, $1.7{\sim}2.3mg\;kg^{-1}$ for Cu and $4.8{\sim}5.5mg\;kg^{-1}$ for Zn, respectively.

• Research in Plant Disease
• /
• v.12 no.2
• /
• pp.108-114
• /
• 2006

This study was conducted to elucidate the interactions among soil microorganisms in a special field where one, two or three of N, P, K fertilizers were continuously not applied for 29 years. Crop yield (barley, soybean), soil chemical properties and microflora and microfauna including nematodes, nematophagous fungi, actinomycetes, bacteria, and fungi were examined for two years. Tylenchorhynchus sp. was the most important plant-parasitic nematode (range $11{\sim}642/300 cm^3$ soil) followed by Pratylenchus sp. and Helicotylenchus sp. Among nematophagous fungi, Monacrosporium spp. was the most frequently found followed by Harposporium sp. and Cystopage sp. In general, plots treated with phosphate fertilizer yielded more, had more nematodes, bacteria and actinomycetes. In contrast, total fungal population densities including nematophagous fungi, Cystopage sp. and Harposporium sp. were in reverse; they were more abundant in the plots with lower phosphate contents. Phosphate and pH are positively correlated and two most important determining factors for the population density of soil organisms under investigation. According to correlation analysis, Ca, Mg, and $SiO_2$ contents in soil and population densities of Tylenchorhynchus sp., saprophitic nematodes, actinomycetes, and bacteria were positively correlated with pH, but were negatively correlated with fungal population densities. We hope that the study will add an additional knowledges to understand our mysterious underworld.

• Korean Journal of Environmental Agriculture
• /
• v.36 no.2
• /
• pp.67-72
• /
• 2017

BACKGROUND:Cultivation of alternative crops in paddy fields is necessary because of the decrease in rice consumption and the increase in excess stock of rice. The study was conducted to investigate the effects of alternative crops cultivation in paddy fields on soil physico-chemical characteristics and crop yield. METHODS AND RESULTS: Soybean (Glycine max), red-clover (Trifolium pratense), and water convolvulus (Ipomoea aquatica) were selected for alternative crops in the first and/or second year and rice was planted in the third year. When alternative crops were cultivated in the previous year, soil bulk density, soil hardness, and water content were lower than those for rice cultivation. Water-depth decreasing rate and aggregate content were greater for the upland-upland-paddy cropping system than upland-paddy-paddy cropping system. Cultivation of red-clover and water convolvulus for two years resulted in the high soil organic matter content. In the third year, available phosphate, exchangeable potassium, and soil cation exchange capacity were relatively high when soybean was cultivated in the previous year. In the first year, water convolvulus cultivation showed greater productivity than red-clover cultivation while the opposite pattern was found in the second year. Rice yield in the third year was greater for soybean or red-clover as a previous crop than for water convolvulus as a previous crop. CONCLUSION: The results suggest that cultivation of alternative crops in paddy fields can improve soil physical properties including bulk density, hardness, water content, and aggregate content as well as rice productivity.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.17 no.2
• /
• pp.49-60
• /
• 2014

This study was conducted to evaluate the effect of forest fire on natural distribution and regeneration of Pinus densiflora Sieb. & Zucc. in Goseong, Gangwon province, Korea. After 13 years of the last forest fire in 2000, five investigation plots ($10m{\times}10m$) in each of rocky land and ridge, the well-known location as a favorite site for natural distribution of P. densiflora, were set to investigate stand characteristic and soil environment including physico-chemical properties and moisture contents of soil. Also, five investigation plots in slope area were set and investigated as well. The concentration of organic matter, total nitrogen, and exchangeable nutrients ($K^+$, $Ca^{2+}$, $Mg^{2+}$) were highest in the slope while the soil in the rocky land showed the lowest concentration of organic matter, total nitrogen, available $P_2O_5$, and exchangeable nutrients ($K^+$, $Na^+$, $Ca^{2+}$, $Mg^{2+}$). The soil in the slope only showed higher concentration of total nitrogen, $K^+$ and $Ca^{2+}$ than the unburned area in Goseong. Mean soil moisture contents in the rocky land (5.77%) were lowest while the slope (15.78%) and the ridge (15.27%) showed almost three times as much than the rocky land. P. densiflora was dominant in the rocky land and Quercus spp. were dominant in the ridge and slope. The average proportion of P. densiflora was highest in rocky land (58.4%, 14.6 trees per plot) followed by the ridge (25.2%, 7.8 trees per plot) and the slope (11.3%, 3.4 trees per plot) while the average height of P. densiflora was highest in slope (277cm) followed by the ridge and the rocky land. The height and crown width of Quercus spp. were higher than P. densiflora in the every plot. The results suggest that P. densiflora may be able to naturally regenerate and survive in the rocky land after the fire while P. densiflora in the ridge and the slope are suppressed by Quercus spp.

• Korean Journal of Soil Science and Fertilizer
• /
• v.40 no.3
• /
• pp.201-207
• /
• 2007

To reduce both the floatation of the seedling of rice and the failure in standing in the paddy field when the barley straw was applied to paddy field before planting the rice, we tested the effect of rice rooting with plowing methods and irrigation rates for 2 years from 2003 to 2004. This study was carried out in paddy field with Fluvio-Marine deposit in Jeonbug series and the operating accuracy and the change of soil physico-chemical properties depending on plowing methods and irrigation rates following the barley straw applying were examined. There was a less floatation of barley straw in the dry-rotaryI+water-rotaryI(DRI+WRI) plot than in the plowing+water-rotary(PL+WRI) plot. The ratio of miss-planted and floating seedling also decreased by 1.7%, 2.6% in the DRI+WRIplot compared with PL+WRI plot. The soil physical property was improved with the decreasing soil hardness, bulk density and increasing soil porosity after the application of barley straw, especially enhanced greatly in the increase of porosity, gaseous phase and with the decrease of soil hardness, bulk density of subsurface soil in DRI+WRI plot. And the change of soil chemical property were increased the content of total carbon$^{\circ}{\S}$nitrogen$^{\circ}{\S}$organic matter and available phosphate while decreased the content of exchangeable cations and available silicate after the application of barley straw. Also the content of organic matter, available phosphate and cation exchangeable capacity were increased, whereas caron/nitrogen ratio was decreased in DRI+WRI plot compared with PL+WRI plot. The number of panicles, spikelets per square meter were increased and 1,000 grains weight of hulled rice was gained more in DRI+WRI plot at irrigation rate of $500ton\;ha^{-1}$, in DRI+WRII plot at irrigation rate of $700ton\;ha^{-1}$. So the rice yields were increased by 7%, in DRI+WRI and 5% in DRI+WRII plot, respectively compared with PL+WRI plot. The result of this study indicated that the most appropriate plowing method with barley straw application on rice cultivation at double cropping in normal paddy field plain land was DRI+WRI.

• Korean Journal of Soil Science and Fertilizer
• /
• v.12 no.3
• /
• pp.125-132
• /
• 1979

A field experiment was conducted to evaluate the effectiveness of an organic fertilizer (Glutamic acid fermentation by product ameded with nitrogen) on the growth and yield of radish and chinese cabbage on a relatively fertile soil. Additional laboratory studies were also made to find out the influence of mentioned fertilizer on the phisical and chemical characteristic of soils. The results are summarized as following. 1. Effect of fertilizer on the growth and yield. a. On a relatively fertile soil with high organic matter content (3%), the organic fertilizer was not effective for the growth and yield of radish and yield of radish and chinese cabbage. b. The application of organic fertilizer increased the K contents in plants both in radish and chinese cabbage. It was observed that the high content of K in radish leave lowered the leaf/root ratio and the leaf/root ratio showed a positive correlation with root weight. 2. Effect on soil physical and chemical properties. a. The application of organic fertilizer resulted in the improvement of soil physical property by lowering bulk density and increasing porosity. b. It was found that application of organic fertilizer increased the water stable soil aggregates. c. The application of organic fertilizer did not result in the significant increase in soil organic matter. d. Soil pH was lowered by the application of organic matter. It was speculated that the oxidation of ammonical nitrogen in the fertilizer is responsible for the lowering of soil pH.

• Korean Journal of Soil Science and Fertilizer
• /
• v.40 no.5
• /
• pp.418-428
• /
• 2007

Physical and chemical properties of the aggregate by-products including sludge and crushed dust samples collected from the 21 private companies throughout the country were analyzed to evaluate possible usage of the by-products as artificial soil materials for plantation. The pH of the materials ranged from 8.0 to 11.0. The organic matter content was $2.85g\;kg^{-1}$, and the total nitrogen content and available phosphate content were low as 0.7 percents and $12.98mg\;kg^{-1}$, respectively. Exchangeable $Ca^{2+}$, $Mg^{2+}$, $K^+$, and $Na^+$ were 2.29, 0.47, 0.02 and $0.05cmol\;kg^{-1}$, respectively. Heavy metal contents were lower than the limits regulated by environmental law of Korea. Textural analysis showed that most of the materials were silt loam with low water holding capacity ranged from 0.67 to 7.41 percents, and with low hydraulic conductivity ranged from 0.4 to $2.8m\;s^{-1}$. Mineralogical analysis showed that the aggregate by product materials were mostly composed of silicate, alumina and ferric oxides except calcium oxide dominant materials derived from limestones. The primary minerals were quartz, feldspars and dolomites derived from granite and granitic gneiss materials. Some samples derived from limestone material showed calcite and graphite together with the above minerals. According to the result, it can be concluded that the materials could be used as the artificial soil material for plantation after proper improvement of the physico-chemical properties and fertility.