Mineral nutrient contents, including K, Ca, Mg,and phosphorus (P) were measured by the dry-ashing method (Tsai, 2009). The extracted solution with 1.2N HCl were used for the atomic absorption (AA) analysis for K, Ca, and Mg, and the ammonium molybdate spectrometric method for P. The wave length for absorbance detecting by AA spectroscopy (Shimadzu AA-6300, Kyoto, Japan) were 766.5 nm, 422.7 nm, and 285.2 nm for K, Ca, and Mg, respectively. The absorbance for determining P was measured at the wave length of 600 nm. Nitrogen (N) content was analyzed by Kjeldahl method (Tsai, 2009).