• Korean Journal of Soil Science and Fertilizer
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• v.36 no.4
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• pp.218-224
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• 2003

Magnesium hydroxide, which recently registered as a Mg fertilizer, is greatly different from magnesium sulfate in its solubility and effect on soil pH. In this study, the effects of magnesium hydroxide and magnesium sulfate on growth of chinese cabbage were compared at the application rate of $300kg\;MgO\;ha^{-1}$ in a Gyeongsan clay loam soil. Although magnesium hydroxide was effective in increasing number of leaf and fresh weight, overall effects of magnesium hydroxide and magnesium sulfate on the growth of chinese cabbage were not significantly different ($p{\leq}0.05$). Comparing the two magnesium fertilizer treatments, magnesium content of chinese cabbage was relatively higher in the magnesium sulfate treatment in the early stage of growth, but it was higher in the magnesium hydroxide treatment at harvest. Contents of Ca, P, and K in chinese cabbage were relatively higher in the magnesium hydroxide treatment than those in magnesium sulfate treatment. But, the differences in nutrient uptakes by chinese cabbage between the treatments were not significant ($p{\leq}0.05$). Therefore, magnesium hydroxide is expected to be used with nearly the same effects on crops as magnesium sulfate at the same application rate of Mg. Soil pH in the treatment of magnesium sulfate was lower than that of control treatment, but magnesium hydroxide could increase pH. Magnesium hydroxide can be used preferentially in acid and/or sandy soils, where magnesium sulfate can induce further soil acidification and leaching loss of Mg is often a severe problem.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.15-22
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• 2010

This study was carried out to investigate the characteristics of ions in rainwater by stem flow, through fall and rainfall in Pinus thunbergii forest in Ulsan industrial complex area and Mt. Jiri area. pH of rainwater in Ulsan industrial complex area was low as compared with those in Mt. Jiri area. EC of rainwater in Ulsan industrial complex area was mainly high and there was twice difference in stemflow and through fall as compared to Mt. Jiri area. The concentration of major ions in rainwater, especially $Ca^{2+}$ and $Mg^{2+}$ in stem flow were generally high at Ulsan industrial complex area, while anions were high in the order of ${SO_4}^{2-}>{NO_3}^{-}>Cl^-$ in both areas. There was a wide difference in ${SO_4}^{2-}$ concentration in the stem flow between both areas. ${SO_4}^{2-}$ from air pollutants will result into acidification of forest soils and thereafter cause damages on forest ecosystems.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.3
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• pp.253-257
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• 1984

A field experiment was conducted in order to secure the basic information on the rational application of nitrogen and potassium for autumn growing Chinese cabbage (Brassica campastris ssp. pekinensis, var.; Miho 70 days). The results of the experiment are summarized as follows: 1. Potassium effect was observed where nitrogen applied either less than 15kg N/10a and heavy dose of 25kg N/10a. No potassium effect was observed where 20kg N/10a applied. In the case of 25kg N/10a, potassium effect was observed only in total weight but failed yield marketable product weighing over 1 kilogram per cabbage. 2. Nitrogen application, in general, tends to lower the soil pH and it is particularly true when heavy dose of over 20kg N/10a is applied. As a result, Chinese cabbage has increasingly removed soil born potassium and reduced exchangeable potassium content of the soil. 3. Oven dried cabbage which received 25kg N/10a plus potassium showed a low concentration of calcium and this phenomena seems to be attributable to the acidification of soils and it further caused failure in producing cabbages of marketing value.