Article | 10. 2015 Vol. 33, Issue. 5
Growth of Red-leaf Lettuce and Changes in Soil Solution Chemical Properties of Coir-dust Containing Root Media Influenced by Application Rates of Pre-planting Fused-Superphosphate



Department of Horticultural Sciences, Chungnam National University1
Department of Biosystems Engineering, Chungbuk National University2




2015.10. 658:667


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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 6.0 g・L-1 in 1.5 g・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 (100 mg・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 PO43- 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 100 mg・L-1, respectively. These were lower pH and higher PO43- 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 SO4-2 concentrations in soil solution of the three root media. The NO3-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 NO3-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 6.0 g・L-1 for pot cultivation of red-leaf lettuce.



1. Bunt, A.C. 1988. Media and mixes for container grown plants. Unwin Hyman, London.  

2. Choi, J.M. 2014. Performance of seedling grafts of tomato as influenced by root medium formulations and leaching fractions in irrigation or fertigation. Protected Hort. Plant Fac. 23:235-243.  

3. Choi, J.M., C.S. Kang, J.W. Ahn, and C.W. Lee. 2011. Influence of fertilizer concentrations on the performance of seedling grafts of tomato grown in coir based root media. Hortic. Environ. Biotechnol. 52: 393-401.  

4. Choi, J.M. and C.W. Lee. 2012. Influence of elevated phosphorus levels in nutrient solution on micronutrient uptake and deficiency symptom development in strawberry cultured with fertigation system. J. Plant Nutr. 35:1349-1358.   

5. Choi, J.M., C.W. Lee, and J.S. Park. 2015. Performance of seedling grafts of tomato as influenced by root substrate formulations, fertigation leaching fractions, and N concentrations in fertilizer solution. Hortic. Environ. Biotechnol. 56:17-21.  

6. Choi, J.M., C.Y. Shim, and J.S. Choi. 2002. Effect of phosphorus fertilization on changes in concentrations of nutrients in rice-hull based root media, crop growth, and nutrient contents of chrysanthemum. J. Kor. Soc. Hort. Sci. 43:235-238.   

7. Choi, J.M., I.Y. Kim, and B.K. Kim. 2009. Root Substrates. Hackyesa. Daejeon, Korea. p. 278-279.  

8. Lim, S.W. 2005. Fertilizers. Ilsinsa, Seoul.  

9. Lindsay, W.L. 2001. Chemical equilibria in soils. The Blackburn Press, Caldwell, NJ.  

10. Nelson, P.V. 2003. Greenhouse operation and management, 6/e. Prentice Hall, NJ.   

11. Marschner, P. 2012. Marschner’s mineral nutrition of higher plants. 3rd ed. Elsevier. New York.  

12. Styer, R.C. and D.S. Koranski. 1997. Plug & transplant production: a grower’s guide. Ball Publishing. Batavia, IL.   

13. Tate, R.L. 1995. Soil microbiology. John Wiley & Sons, Inc., New York.   

14. Taiz, L. and E. Zeiger. 2006. Plant Physiology, 4th ed. Sinauer Associates Inc., Sunderland, MA.