• Korean Journal of Soil Science and Fertilizer
• /
• v.8 no.2
• /
• pp.53-60
• /
• 1975

Vegetables are often cultivated continuously year round in a vinyl house with heavy application of fertlilizers, which leads to accumulation of salts in the soil. A field experiment was conducted to investigate the effect of watering on salt eluviation from the soil, and on the yield of tomatoes in the vinyl house. The results were summarized as the followings: The salt eluviation increased with the amount of water applied. The efficiency of the salt eluviation was greater for the silty clay loam soil than the sandy loam soil. With a given amount of water, the efficiency increased with frequency of watering. The yield of tomatoes was increased by watering. However, the yield was not necessarily correlated to the amount of salt leached. Increase in yield of tomatoes by watering was in order of the treatment, 100mm (50-50), 150mm (50-50-50 or 100-50), and 200mm (100-100) of water for both soils. Relationship between the yield of tomatoes and electrical conductibity of the soil (1 : 5 extract) was described by the following regression equation : $Y=1,739.0+437.5X-290.5X^2$ $(R=0.632^{**})$ for sandy loam soil, and $Y=1.542.2+454.1X-275.0X^2$ $(R=0.622^{**})$ for silty clay loam soil. The yield of tomatoes in salt accumulated soil was inversely correlated to extractable sodium and potassium, and to the ratio of extractable sodium to calcium (Na/Ca), while the yield was not correlated to extractable calcium and magnesium.

• Korean Journal of Environmental Agriculture
• /
• v.20 no.2
• /
• pp.112-115
• /
• 2001

Salt accumulation and movement by runoff ware studied in runoff resevior lysimeter constructed in a green house located in the area of Cheongju, Chungbuk province. Average runoff ratio of rainfall within period of this experiment was 58%. The average content of cations lost from field soil by runoff was in the order of $Ca^{2+}(27.12\;mg/L\;)$ > $K^+(9.18\;mg/L)$ > $Mg^{2+}(2.53\;mg/L)$ > $Na^+(1.89\;mg/L)$ and in the care anions $SO_4\;^{2-}(63.38\;mg\;/L)$ > $NO_3\;^-(25.40\;mg/L)$ > $Cl^-(4.19\;mg/L)$ > $PO_4\;^{3-}(3.18\;mg/L)$. Amounts of salt movement by runoff $SO_4\;^{2-}(140.2\;kg/ha)$, $Ca^{2+}(59.9\;kg/ha)$, $NO_3\;^-(56.1\;kg/ha)$, $K^+(20.3\;kg/ha)$, $Cl^-(9.3\;kg/ha)$, $PO_4\;^{3-}(7.0\;kg/ha)$, $Mg^{2+}(5.6\;kg/ha)$ and $Na^+(4.2\;kg/ha)$. The loss amount of $PO_4\;^{3-}$ was the lowest among the anions investigated in this experiment. $P_2O_5$ was accumulated on the soil surface due to strong affinity for the sorption site on the soil particle surface.

• Korean Journal of Soil Science and Fertilizer
• /
• v.41 no.5
• /
• pp.310-317
• /
• 2008

This study was carried out to investigate the factors of desalinization of the rainfall interception culture soils of Rubus sp. in Gochang-gun, Jeollabuk-do. Soil samples were collected from 85 different sites of the rainfall interception culture soils of Rubus sp. in Gochang-gun, Jeollabuk-do. The electrical conductivity in paste saturation of rainfall interception culture soils ranged from $1.0\sim28.4dS\;m^{-1}$ (average: $4.8dS\;m^{-1}$) and salt affected soil which EC was higher than $4dS\;m^{-1}$, covered nearly 55% of all field surveyed. Salts in rainfall interception culture soils were accumulated by increasing the cultivation period. Electrical conductivity in rainfall interception culture soils was positively correlated with water soluble anions such as chloride ion ($r=0.85^{**}$), nitrate ion ($r=0.94^{**}$), phosphate ion ($r=0.88^{**}$), and sulfate ion ($r=0.84^{**}$), respectively. As a result of desalinization experiments carried out by water management practices, the rinsing method was more effective than leaching method.

• Korean Journal of Soil Science and Fertilizer
• /
• v.24 no.4
• /
• pp.260-264
• /
• 1991

To investigate the proper fertilization position in the soil accumulated with phosphorus and salt, tomato, Seo-Kwang, was planted on the bottomless pot, 45cm diameter 30cm length, filled with three different soils ranged 567 to 1,140 ppm of available phosphorus (0.45~3.69 mmhos/cm in electrical conductivity). Fertilizer phosphorus was treated at three different sites of side 0~5,6~10, 11~15cm and three different sites of depth; 0~5, 6~10, 11~15cm, The results are follows; Fertilizer use efficiency (FUE) of phosphrous of tomato was decreased as avilable phosphorus in soil increased. Highest FOE of phosphorus was showed at band application of feliilizer phosphorus at 0~5cm side and 11~15cm depth in the soil contain ing 567ppm of available phosphorus, and 6~10cm side and 0~5cm depth in the soils containing 942 and 1,140ppm of phosphorus. At 45 days after planting tomato root was highly distribued to 0~5cm side and depth respectively in low salt soil (0.45mmhos/cm), 11~15cm depth in 2.61mmhos/cm soil and 6~10cm depth in 3.69mmhos/cm. The fertilizer use efficiency of phosphorus of tomato plant war negatively significantly correlated with soil EC and phosphate concentration at 45 days after planting. The fertilizer use efficiency of phosphorus was more highly correlated with available phosphorus than electrical conductivity in soil.

• Journal of Integrative Natural Science
• /
• v.4 no.2
• /
• pp.103-112
• /
• 2011

This study was carried out on 4 batch reactors to determine the specific ammonium oxidizing rate (SAOR), specific nitrate forming rate (SNFR) and inhibitory degree of nitrifying activities with saline concentrations. Under salt free condition ammonia was consumed during the reaction period within 200 min. When the salt level increased to 10, 20 and 30 g $NaClL^{-1}$ in reactor, ammonia depletion took 250, 300 and above 350 min, respectively. During concentration above 10 g $NaClL^{-1}$, there was nitrite accumulation. Also, at 30 g $NaClL^{-1}$ ammonia did not depleted and $NO_2{^-}$-N accumulated until the final reaction. Nitrate formation rates decreased with increasing salt concentration. SAOR and SNFR showed a decreasing trend as salinity concentrations were increased. The SAOR was reduced from 0.2 to 0.08 mg $NH_4{^+}$-N $g^{-1}VSS\;day^{-1}$ as the salt concentration increased from 0 to 30 g $NaClL^{-1}$. Similarly, the SNFR decreased from 0.26 kg $NO_3{^-}$-N $kg^{-1}VSS\;day^{-1}$ at saline free to 0.1 kg $NO_3{^-}$-N $kg^{-1}VSS\;day^{-1}$ at saline 30 g L-1. A severe inhibition of nitrifiers activity was observed at increased salt concentrations. The inhibition ratio of specific ammonium oxidation rates were 17, 47 and 60% on the reactor of 10, 20 and 30 g $NaClL^{-1}$ added, respectively. The inhibition ratio of specific nitrate forming rates also were inhibited 30, 53 and 62% on the reactor of 10, 20 and 30 g $NaClL^{-1}$ added, respectively. As the salinity concentrations increased from 0 to 30 mg $NaClL^{-1}$, the average MLSS concentration increased from 1,245 to 1,735 $mgL^{-1}$. The SS concentration of supernatant in reactor which settled about 30 minutes was not severely difference between concentration of salt free reactor and one of those high salt contained reactors.

• Korean Journal of Soil Science and Fertilizer
• /
• v.39 no.6
• /
• pp.372-379
• /
• 2006

This study was carried out to improve chemical properties of salt-accumulated plastic film house soil. Compressed expansion rice hull was applied at 0, 2.5, 5.0, $7.5Mg\;ha^{-1}$, and drip irrigation was initiated at -33 kilopascals (kPa) of soil water potential and ceased adjusted up to -10 kPa. Another treatment was the application of inflated rice hull at $5.0Mg\;ha^{-1}$ with drip irrigation starting at soil water potential -20 kPa and adjusted to -10 kPa. Lettuce(Lactuca sativa L.) was cultivated at sandy loam soil with $5.1dS\;m^{-1}$ of electrical conductivity (EC). $EC_w$(1:5) of plots treated with $5.0Mg\;ha^{-1}$ of inflated rice hull and irrigated at the point of -20 kPa and -33 kPa of soil water potential was reduced by 26% and 24% less than untreated control plot, respectively. Soil $EC_w$(1:5) has close relationship with $Cl^-$ as well as $NO_3{^-}-N$ and $SO{_4}^{2-}$ in the soil. Total nitrogen in leaf of lettuce was deficient in the earlier growth stage. The yield of lettuce increased by 6% by the application of inflated rice hull of $5.0Mg\;ha^{-1}$ with drip irrigation starting at -33 kPa of soil water potential. It decreased 4% when the drip irrigation was stated at -20 kPa of soil water potential. The amount of water used for irrigation was reduced with the increasing application of inflated rice hull. The watering initiated at the point of -33 kPa was more economical compared with starting at -20 kPa.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.6
• /
• pp.949-954
• /
• 2012

This study is conducted to evaluate the effects of chelating agents for improving plant growth and reusing accumulated nutrients in soils of plastic film house. Two experiments were carried out at follows: i) The incubation test was conducted using soils treated with 0, 300 mM of EDTA and DTPA to examine the availability of nutrients. ii) For the pot test, chinese cabbages were cultivated in soils with 0, 0.1, 0.5, 1, and 5 mM of EDTA and DTPA to examine the impacts of plant growth response. The application of chelating agents increased ther availability of soil nutrients in the following order: DTPA > EDTA > control. Inorganic concentration of chinese cabbages in DTPA treatments consderably increased in nitrogen, phosphate, iron and aluminium contents than that of the other treatments. The optimal concentration of DTPA for vigorous plant growth as 0.5 mM. Thus, DTPA was more effective than other chelating agents for healty growth of cabbages and the availability of nutrients accumulated in plastic film house.

• Korean Journal of Soil Science and Fertilizer
• /
• v.38 no.2
• /
• pp.85-91
• /
• 2005

Nutrients are built up in paddy soils after greenhouse vegetable cultivations with relatively high rates of chemical fertilizers and composts during winter season, and the continuous nutrient accumulation is problematic in crop cultivation. Rice cultivation after greenhouse vegetables is one option for removing the accumulated nutrients in the soils. The object of this experiment was to examine the effect of reduced fertilization to rice on the removal of accumulated soil nutrients and rice yield in greenhouse vegetables and rice cropping system. Experiments were carried out at Changwon and Uiryeong in Gyeongnam province in 2001. The cropping systems were watermelon-rice and pumpkin-watermelon-watermelon-rice in Changwon and Uiryeong, respectively. The soils were Gangseo series (coarse loamy, mixed, nonacid, mesic family of Aquic Fluventic Eutrochrepts) at Changwon and Hampyeong series (fine loamy, mixed, mesic family of Fluvaquentic Dystrochrepts) at Uiryeong. Treatments of conventional fertilization ($N-P_2O_5-K_2O=11-4.5-5.7$, $kg\;10a^{-1}$), no basal fertilization, no top dressing, and no fertilization were included in the experiments. Plant growth and total nitrogen content in the plant were greater as the amount of fertilizer applied were increased. Whereas $SiO_2/T-N$ rate in rice plant and nitrogen use efficiency were greater as the amount of fertilizer applied were reduced. Rice yields were not significantly different among the treatments of conventional, no top-dressed, and no-basal fertilization in Uiryeong, and the rice yields were significantly also not different between the treatments of conventional and no top-dressed in Changwon. The removal of salts in soils after rice cultivation was the highest at the treatment of no-basal fertilization in both of the sites. Therefore, reduced fertilization for rice cultivation after greenhouse vegetables could remove salts accumulated in paddy soils without any significant reducing of rice yield.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.25 no.3
• /
• pp.79-89
• /
• 2017

Changes in pH, EC and water soluble cation and anion of the bed material in the rearing box of earthworms were investigated while sewage sludges or night soil sludge were cumulatively supplied to the 15 grams of initial earthworm population in the rearing box. Initial biochemical properties of sludges such as pH, EC, V.S. and water content were at the edible levels for earthworm. However, as the cumulative amount of sludges supplied to the earthworms were increased, pH of bed material in the rearing box was lowered and EC was increased, which meant that salt contents of bed material in the rearing box had been accumulated. Water soluble cations and anions were also accumulated in the bed material of the rearing box. Accumulation rates of ${NO_3}^-$ were especially prominent. Consequently, feeding rates of earthworm populations were reduced to nearly zero and earthworm populations finally died.

• Korean Journal of Soil Science and Fertilizer
• /
• v.46 no.6
• /
• pp.641-646
• /
• 2013

Chemical properties of agricultural soils in Korea have been investigated at four-year interval in order of paddy, polytunnel, upland, and orchard soils since 1999; polytunnel soils were investigated over the whole country in 2000, 2004, 2008, and 2012. Polytunnel soils were taken from the surface (0-15 cm) and subsurface (15-30 cm) at 2,651, 1,274, 1,374 and 1,374 sites in all provinces of South Korea. One hundred sampling sites located in more than 400 m altitude were additionally investigated in 2008 and 2012. Average of soil chemical properties in 2012 except Jeju province were 6.6 for pH, 3.2 dS $m^{-1}$ for EC, 37 g $kg^{-1}$ for organic matter (OM), 1,049 mg $kg^{-1}$ for available (Avail.) phosphate, 1.58 $cmol_c\;kg^{-1}$ for exchangeable (Exch.) K, 10.6 $cmol_c\;kg^{-1}$ for Exch. Ca, and 3.3 $cmol_c\;kg^{-1}$ for Exch. Mg. Except pH, averages of all chemical properties exceeded the upper limit of optimal range. The median values except pH showed a lower value than the averages. The pH, OM and Exch. Ca had slightly increased from 6.3 to 6.6, from 34 to 37 g $kg^{-1}$, and from 7.7 in 2000 to 10.6 $cmol_c\;kg^{-1}$ in 2012, respectively. The order of sample ratios exceeding the optimal range were Avail. $P_2O_5$ (83%) > Exch. Ca (80%) > Exch. K (70%) > Exch. Mg (65%) > EC (55%) > OM (48%) > pH (29%) in 2012. The order of sample ratios below the optimal range was OM (25%) > Exch. K (25%) > pH (20%), Exch. Mg and Avail. $P_2O_5$ (9%) > Exch. Ca (6%) in 2012. The excessive proportion of pH, Exch. Ca, Exch. Mg and OM slightly increased, while the insufficient proportion of those decreased. Approximately 55% of polytunnel soils exceeding EC 2 dS $m^{-1}$ was evaluated with salt accumulated soils having the risk of growth disorder of crops. Nutrient contents in polytunnel soils in Korea showed high level especially Avail. $P_2O_5$ and Exch. cations. Therefore, recommended fertilization based on soil testing or plant testing is needed for soil nutrient management.