충북(忠北) 지역(地域) 시설재배(施設栽培) 토양(土壤)의 화학적(化學的) 특성(特性)

Chemical Characteristics of Plastic Film House Soils in Chungbuk Area

시설재배 토양의 염류집적 현황과 토양중 염류이동을 구명하기 위하여 충북지역의 청주 및 충주에서 토양의 화학적 특성을 조사하였다. 시설재배지의 토성(土性)은 사양토(砂壤土) 30%, 양토(壤土) 27%, 미사질양토(微砂質壤土) 43% 이었고, 표토의 염류농도 분포비율은 $2dS\;m^{-1}$ 이하가 23%, $2{\sim}4dS\;m^{-1}$ 30%, $4{\sim}6dS\;m^{-1}$ 25%, $6dS\;m^{-1}$ 이상이 22%로서 장해발생기준(障害發生基準) $4dS\;m^{-1}$를 초과하는 포장이 약 50% 이었으며, 심토(20~30cm)에서는 $2dS\;m^{-1}$ 이하인 토양이 68%이었다. 시설재배 토양의 EC는 경작년수에 따라 증가하여 5년 이상인 토양에서 $4.47dS\;m^{-1}$ 이상이었고 시설 밖의 노지포장보다 2.8~5.6배 높았다. 여름철 비닐을 제거한 토양의 EC는 $0.71{\sim}2.92dS\;m^{-1}$로서 제거하지 않은 토양의 $3.54{\sim}7.36dS\;m^{-1}$보다 현저히 감소되었다. 시설 재배 토양의 $NO_3-N$, $SO_4-S$ 그리고 Cl 함량은 노지토양에 비하여 각각 2.5. 7.0, 3.4배 높았다.

The salt accumulation, and chemical properties of 90 samples of the plastic film house soil in the area of Cheongju and Chungju were surveyed. Soil textural distribution of soil samples was 30% for sandy loam, 27% for loam and 43% for silty loam. Percentage distribution of electrical conductivity(EC) of surface soil was 23% below $2dS\;m^{-1}$, 30% for $2{\sim}4dS\;m^{-1}$, 25% for $4{\sim}6dS\;m^{-1}$ and 22% over $6dS\;m^{-1}$. Salt affected soil, which EC was higher than $4dS\;m^{-1}$, covered nearly 50% of all field surveyed. However subsoils(20~30cm) below $2dS\;m^{-1}$ was 68%. Salts in plastic film house soil was accumulated by increasing the cultivation period. After 5 years of cultivation electrical conductivity in plastic house soil was generally higher than $4.47dS\;m^{-1}$ in EC that was 2.8~5.6 times higher than that in the field soil in the outside of plastic film house. As the result of temporary removal of plastic film cover from the house during the rainy summer season, salt content in soil was decreased from $3.54{\sim}7.36dS\;m^{-1}$ to $0.71{\sim}2.92dS\;m^{-1}$ in EC due to the desalinization by runoff and percolating water. Contents of $NO_3-N$, $SO_4-S$ and Cl in plastic film house soil were 2.5. 7.0 and 3.4 times higher than those of open field respectively.