Effect of Flooding Treatment to Desalinize Greenhouse Soil after Vegetable Cropping.
Minkyeong Kim, Keean Roh, Myungchul Seo, Yeonkyu Sonn, Namjong Lee, and Munhwan Koh. Division of Agricultural Environment and Ecology, National Institute of Agricultural Science and Technology, 249 seodundong, Suwon, South Korea
Greenhouse soils have been intensively cultivated with excessive compost and chemical fertilizer for vegetable growth. Thus, this study was aimed at investing the effect of desalting method, flooding soil surface, after vegetable cropping in greenhouse soil. Field experiments from July to September 2005 were conducted to quantify greenhouse soils, i.e., Sachon soil series (sandy, mixed, mesic family of local valley) and Seogcheon soil series (sandy, mixed, mesic family of alluvial plain). The values of Electrical Conductivity (EC), available phosphate, and exchangeable potassium after the flooding in all soils were lower than those before the treatment. The changes of desalinization in both soil series were higher as the amounts of irrigated and drained water were increased. Particularly, the ratio of desalinization in alluvial plain was much higher (66.7%) than the one in local valley (45.6 %). However, NH4-N contents of local valley soils during the flooding were higher than in those of alluvial plain. Nutrient concentrations of surface water in local valley and alluvial plain were 0.13~0.85 and 0.04~0.40 mg L-1 for NH4-N, 2.35~6.26 and 3.58~8.08 mg L-1 for NO3-N, and 1.13~5.92 and 0.12~2.71 mg L-1 for PO4-P, respectively. This was cased by high total nitrogen and organic matter in local valley soils than those in alluvial plain soils. Therefore, this study suggested that the flooding soil surface would be the good treatment to desalinize greenhouse soils. An additional finding of this study was that flooding water containing high N and P concentration might be a potential pollutant to streams or tributaries since they can be the main cause of eutrophication problem. This leads the further study which is the conservation of soil and water quality to implement the best management practice in greenhouse soil. Key words; Greenhouse soil, Desalinization, Flooding method, Nitrogen, Phosphorous