• Horticultural Science & Technology
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• v.33 no.5
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• pp.658-667
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• 2015

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.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.499-506
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• 2014

This research was conducted to develop root media containing ground and aged pine bark (GAPB) and ground and raw pine bark (GRPB). After analysis of physico chemical properties, the pine barks were blended with peat moss (PM) or coir dust (CD) in various ratios to formulate 12 root media. Then, two out of 12 root media were chosen based on the physical properties for further experiments. The pre-planting nutrient charge fertilizers (PNCF) were incorporated into two root media and chemical properties were analysed again. The total porosity (TP), container capacity (CC), and air-filled porosity (AFP) of GAPB were 78.7%. 39.4%, and 38.3%, respectively, while those of GRPB were 74.7%, 41.2%, and 33.4%, respectively. The percentage of easily available water (EAW, from CC to 4.90 kPa tension) and buffering water (BW, 4.91-9.81 kPa tension) in GAPB were 12.7% and 8.5%, respectively, which were a little lower than the 13.5% and 8.8% in GRPB. The pH and EC were not different significantly, but cation exchange capacity was different between the two pine barks (GAPB: pH 5.26, EC $0.61dS{\cdot}m^{-1}$, CEC $15.7meq{\cdot}100g^{-1}$; GRPB: pH 5.19, EC $0.32dS{\cdot}m^{-1}$, CEC $9.32meq{\cdot}100g^{-1}$). The concentrations of exchangeable cations in GAPB were Ca 0.32, K 0.05, Mg 0.27 and $0.12cmol+{\cdot}kg^{-1}$, whereas those in GRPB were Ca 0.28, K 0.08, Mg 0.25 and $0.09cmol+{\cdot}kg^{-1}$. The concentrations of $PO_4$-P, $NH_4$-N and $NO_3$-N were 485.8, 0.62 and $0.91mg{\cdot}L^{-1}$ in GAPB and 578, 1.00 and $0.82mg{\cdot}L^{-1}$ in GRPB, respectively, when those were analyzed in the solution of the saturated paste. The TP, CC and AFP in the two selected media were 89.3 and 76.3, and 13.0% in PM+GAPB (8:2, v/v) and 88.2, 68.2 and 20.0% in CD+GRPB (8:2), respectively. The pHs and ECs were 3.8 and $0.24dS{\cdot}m^{-1}$ in PM+GAPB which were a little lower than 5.8 and $0.65dS{\cdot}m^{-1}$ in CD+GRPB. However, the pHs analysed before and after incorporation of PNCF in the two root media did not show large differences. This is because the solubility of dolomitic lime is very low, and the pH it is expected to rise gradually when crops are cultivated int he root media. The information obtained in this study should facilitate effective formulation of root media containing pine bark.

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.217-224
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• 2006

Objective of this research was to determine the effect of application rate of dolomite in root media containing micronutrient mixes on growth of marigold 'Orange boy' in plug trays. To achieve this, three granular micronutrient mixes such as HF 1, MF 2, and MF 3 were produced and incorporated into three root media, peatmoss+composted pine bark (1:1, v/v, PB), peatmoss+composted rice-hull (1:1, v/v, PR), and peatmoss+composted saw-dust (1:1, v/v, PS), with a rate of $0.3g{\cdot}L^{-1}$. Elevated application rate of dolomite in PB medium containing MF 1 decreased crop growth at 35 days after sowing with the highest fresh and dry weight in the control treatment of dolomite. The treatments of 3.0 and $6.0g{\cdot}L^{-1}$ of dolomite in PB medium containing MF 2 produced 0.133g of dry weight and 0.686g of fresh weight, respectively, which were the highest among treatments of dolomite. But the treatments of 3.0 and $6.0g{\cdot}L^{-1}$ of dolomite in PB medium containing MF 3 produced the highest fresh and dry weight, respectively. Elevated application rate of dolomite in PR medium containing MF 1, 2, and 3 resulted in decrease of fresh an dry weight. The relative growth suppression induced by elevated application rate of dolomite was more severe when MF 3 were incorporated than MF 1 and 2. The treatments of 3.0 and $6.0g{\cdot}L^{-1}$ of dolomite in PS medium containing MF 1 and 3 showed good growth, but elevated application rate of dolomite in PS medium containing MF 2 and control resulted in increase of dry and fresh weight. These results indicated that the application rate of dolomite should be adjusted by kinds of root media and micronutrient mixes.

• Journal of Bio-Environment Control
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• v.15 no.2
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• pp.196-203
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• 2006

Objective of this research was to determine the effect of application level of fused superphosphate (FSPP) in root media containing granular micronutrient fertilizers (MF) on growth of marigold 'Orange boy' in plug culture. To achieve this, three granular micronutrient mixes such as MF 1, MF 2, and MF 3 were produced and incorporated into three root media, peatmoss+composted pine bark (1:1, v/v, PB), peatmoss+composted rice-hull (1:1, v/v, PR), and peatmoss+composted saw-dust (1:1, v/v, PS), at a rate of $0.3g{\cdot}L^{-1}$. Elevated application level of FSPP in PS medium containing each of MF resulted in increase of plant growth such as plant height, plant width, stem diameter, fresh weight and dry weight at 35days after sowing. The dry weight in the treatment of MF 1, MF 2, MF 3, and control fertilized with $9.0g{\cdot}L^{-1}$ of FSPP were 0.066g, 0.103g, 0.077g, and 0.095g per plant, respectively. These results indicated that each of MF affected marigold plug seedlings differently. The application level of FSPP resulted in the heaviest fresh and dry weight in PR medium were $9.0g{\cdot}L^{-1}$ in MF 1, $3.0g{\cdot}L^{-1}$ in MF 2, $9.0g{\cdot}L^{-1}$ in MF 3, and $6.0g{\cdot}L^{-1}$ in control. Elevated application level of FSPP in PB medium containing each of the micronutrient mix increased fresh and dry weight. The general trends in response of plant growth to elevated FSPP were linear and quadratic. The dry weight in the treatment of MF 1, MF 2, MF 3, and control fertilized with $9.0g{\cdot}L^{-1}$ of FSPP in PB medium were 0.131g, 0.104g, 0.137g, and 0.111g per plant at 35days after sowing. These results indicated that MF 1 and MF 3 performed better than MF 2 and control treatments in growth of marigold plug seedlings.

• Horticultural Science & Technology
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• v.31 no.5
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• pp.558-564
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• 2013

The objective of this research was to secure the fundamental information in changes of soil physical properties as influenced by the compaction of root media during container filling. Three root media were formulated by blending peatmoss (PM) with expanded rice hull (PM + ERH, 8:2, v/v), carbonized rice hull (PM + CRH, 6:4) and ground and aged pine bark (PM + GAPB, 8:2). Based on the optimum bulk density, the amount of root media filled into 6.0, 7.5, 8.5, 10.5 and 12.5 cm were adjusted to 90, 100, 110, 120, and 130%, then the changes in total porosity (TP), container capacity (CC), and air-filled porosity (AFP) were measured. The TP decreased significantly as the packing amount of three root media were elevated in all sizes of container. The TP did not show significant differences among the root media in small sizes of containers, but showed significant differences when sizes of containers became larger. As packing amount of three root media were elevated, the CCs in all sizes of containers were decreased. The PM + CRH had the lowest CC among three root media in containers smaller than 8.5 cm, but had the highest CC in those larger than 10.5 cm. These results indicated that the decreases in CC were influenced by the sizes of containers as well as kinds of root media. The elevation of packing amount in three root media diminished significantly the AFP. The AFP in PM + GAPB medium was two times as high as those of PM + ERH or PM + CRH when equal packing densities were applied in all sizes of containers. As the container sizes became larger in three root media, the extents in decreasing of CC were distinct than those of AFP. Above results indicate that elevation in packing amount of three root media decreased significantly the TP, CC and AFP, but these were influenced differently by sizes of containers and kinds of root media. The results would be useful for expectation in the changes of physical properties in various sizes of containers filled with peatmoss based root media.