Chemical Characteristics of Ground Water for Hydroponics and Waste Nutrient Solution after Hydroponics in Chungbuk Area

This survey has been conducted to obtain basic data of the quality of ground water for hydroponics and waste nutrient solution after hydroponics in hydroponic farms in Chungbuk area. Ground water samples were collected and analyzed at 19 sites of hydroponic farms. Waste nutrient solution samples were analyzed at 15 sites selected of them. The values of several components in ground water for hydroponics were as follows. pH range was shown from 6.2 to 7.7 and the average was 6.8. EC range was shown from 0.10 to 0.45 dS $m^{-1}$ and the average 0.23 dS $m^{-1}$. $NO_3-N$ concentrations was ranged from 0.12 to 13.77 mg $L^{-1}$, $SO_4^{2-}$ concentrations was ranged from 1.84 to 63.01 mg $L^{-1}$ and $Cl^-$ concentrations were ranged from 10.46 to 72.09 mg $L^{-1}$. Average values of $NO_3-N$, $SO_4^{2-}$ and $Cl^-$ were 4.00 mg $L^{-1}$, 12.70 mg $L^{-1}$ and 27.57 mg $L^{-1}$, respectively. $Ca^{2+}$, $Mg^{2+}$ and $Na^+$ concentrations were ranged from 3.24 to 36.99 mg $L^{-1}$, 1.44 to 14.93 mg $L^{-1}$ and 6.12 to 25.25 mg $L^{-1}$, respectively. Average concentrations were 13.06 mg $L^{-1}$ in $Ca^{2+}$, 6.02 mg $L^{-1}$ $Mg^{2+}$ and 12.08 mg $L^{-1}$ in $Na^+$. In waste nutrient solution after hydroponics, pH range was shown from 4.3 to 8.8 and the average was 6.7. EC range was shown from 0.44 to 2.37 dS $m^{-1}$ and the average 1.15 dS $m^{-1}$. Range of $NO_3-N$, $PO_4-P$, $K^+$, $Ca^{2+}$, $Mg^{2+}$ and $Na^+$ in waste nutrient solution were $10{\sim}212$, $0.56{\sim}26.1$, $10{\sim}295$, $16{\sim}215$, $9{\sim}54$ and $10{\sim}53$ mg $L^{-1}$ respectively. Average concentration were 100 mg $L^{-1}$ in $NO_3-N$, 12.15 mg $L^{-1}$ in $PO_4-P$, 99 mg $L^{-1}$ in $K^+$, 78 mg $L^{-1}$ in $Ca^{2+}$, 26 mg $L^{-1}$ in $Mg^{2+}$ and 26 mg $L^{-1}$ in $Na^+$. Inorganic matters in waste nutrient solution after hydroponics was higher than that of ground water for hydroponics.

충북지역 양액 재배용 지하수 및 폐양액의 화학적 특징

본 조사는 충북지역의 양액재배 농가에서 양액재배를 위한 지하수 수질과 양액 재배 후 버려지는 폐양액의 수질에 대한 기초 자료를 얻고자 수행되었다. 양액재배를 위한 지하수의 수질 조사는 19개 지점의 양액재배농가에서 수집하여 분석하였고, 폐양액은 그중 15개 지점을 선택하여 분석하였다. 양액재배에 이용되는 지하수의 수질 분석결과 pH의 수준은 $6.2\sim7.7$이었고, 평균은 6.8이었다. EC의 분포범위는$0.10\sim0.45$ dS $m^{-1}$ 이었고, 평균은 0.23 dS $m^{-1}$ 이었다. $NO_3-N$ 농도의 분포범위는 $0.12\sim13.77$ mg $L^{-1}$, $SO_4^{2-}$의 분포범위는 $1.84\sim63.01$ mg $L^{-1}$, 그리고 $Cl^-$의 분포범위는 $10.46\sim72.09$ mg $L^{-1}$이었다. 그들의 평균값은 각각 4.00 mg $L^{-1}$, 12.70 mg $L^{-1}$ 및 27.57 mg $L^{-1}$이었다. $Ca^{2+}$, $Mg^{2+}$ 및 $Na^+$의 분포 범위는 각각 $3.24\sim36.99$ mg $L^{-1}$, $1.44\sim14.93$ mg $L^{-1}$ 및 $6.12\sim25.25$ mg $L^{-1}$이었고, 평균 농도 값은 $Ca^{2+}$ 13.06, $Mg^{2+}$ 6.02 및 $Na^+$ 12.08 mg $L^{-1}$이었다. 양액재배 후 버려지는 폐양액에서 pH 수준은 $4.3\sim8.8$ 이었고, 평균은 6.7이었다. EC의 분포범위는 $0.44\sim2.37$ dS $m^{-1}$이었고, 평균은 1.15 dS $m^{-1}$이었다. $NO_3-N$, $PO_4-P$, $K^+$, $Ca^{2+}$, $Mg^{2+}$ 및 $Na^+$ 의 분포범위는 각각 $10\sim212$, $0.56\sim26.1$, $10\sim295$, $16\sim215$, $9\sim54$ 및 $10\sim53$ mg $L^{-1}$이었다. 평균 농도 값은 $NO_3-N$ 100, $PO_4-P$ 12.15, $K^+$ 99, $Ca^{2+}$ 78, $Mg^{2+}$ 26 및 $Na^+$ 26 mg $L^{-1}$이었다. 양액 재배 후 버려지는 폐양액 중의 무기성분 함량은 양액재배에 이용되는 원수에 비해 상당히 높아졌다.