코이어 더스트 혼합상토에 용과린의 시비수준에 의한 적축면 상추의 생장과 근권부 화학성 변화

This research was conducted to investigate the influence of various levels of fused superphosphate as pre-planting fertilizer on the growth of red-leaf lettuce and changes in the chemical properties of the soil solution in three root media, namely coir-dust plus expanded rice hull (8:2, v/v; CD+ERH), carbonized rice hull (6:4; CD+CRH), or ground and aged pine bark (8:2; CD+GAPB). The amounts of fused superphosphate (FSP) incorporated into the three root media during formulation were controlled from 0 to $6.0g{\cdot}L^{-1}$ in $1.5g{\cdot}L^{-1}$ increments. The root media containing fertilizers were packed into 300 mL plastic pots and seedlings of red-leaf lettuce at the 3rd leaf stage were transplanted. After transplanting, the crops were fed with a solution of neutral fertilizer ($100mg{\cdot}L^{-1}$). The growth of red-leaf lettuce was investigated 5 weeks after transplanting and soil solutions were extracted and analyzed every week for pH, EC, and concentrations of macro-nutrients. The elevation of application rates of FSP in the three root media resulted in better growth, and the crops grown in CD+ERH and CD+GRPB had greater fresh and dry weights than those in CD+CRH when compared among the treatments of equal amounts of FSP. The pH and $PO_4{^{-3}}$ concentrations in the soil solution of CD+CRH at 3 weeks after transplant were in the ranges of 4.0 to 4.8 and 20 to $100mg{\cdot}L^{-1}$, respectively. These were lower pH and higher $PO_4{^{-3}}$ concentrations than those in CD+ERH and CD+GAPB. The $K^+$ concentrations were higher in CD+CRH than those in the other two root media, and the elevation of FSP application rates resulted in higher $Ca^{+2}$, $Mg^{+2}$ and $SO_4{^{-2}}$ concentrations in soil solution of the three root media. The $NO_3$-N concentrations in soil solution rose continuously during crop cultivation, implying that the leaching percentage was elevated. The soil solution EC varied, showing the same tendencies as the $NO_3$-N concentrations. The above results indicated that the CD+ERH and CD+GRPB media performed better than CD+CRH, and optimum application rates of FSP in the three root media were 4.5 to $6.0g{\cdot}L^{-1}$ for pot cultivation of red-leaf lettuce. 코이어 더스트(coir-dust, CD)와 팽연왕겨(expanded rice hull, ERH), 훈탄(carbonized rice hull, CRH), 및 분쇄수피(ground pine bark, GRPB)를 혼합하여 조제한 CD+ERH(8:2, v/v), CD+CRH(6:4) 및 CD+GRPB(6:4)의 세 종류 혼합상토에 기비로 혼합된 용과린의 시비수준이 적축면 상추의 생장과 근권부 화학성 변화에 미치는 영향을 구명하기 위하여 본 연구를 수행하였다. 용과린을 $0.0-6.0g{\cdot