| Summary: | 碩士 === 國立臺灣大學 === 農業化學研究所 === 88 === AbstractTwo purposed practices for sustainable cultivation has been set up at Chishan, Kao-Hsiung county. The trail included six treatments with the combinations of three cultivation methods (organic, O; intermediate, I; conventional, C) and two rotation systems (the rotation system I, R1; the rotation system II, R2). Each treatment (with plot size 0.1 ha) had no replication. The soil characteristics have been changed after different cultivation management for 11 years. The purposes of this study were to investigate the effects of different kinds of fertilizer on soil characteristics, nutrient release pattern and fertilization reaction between soils of different cultivation history. The soils used in this study were sampled from Chisan, where the field study with different cultivation method has been practiced for 11 years. This study included a organic fertilizer, a chemical fertilizer treatment and a no fertilizer-treated control. The application rate of organic fertilizer was 100 g kg-1 soil and that of chemical fertilizer was 100-75-50 (N-P2O5-K2O) mg kg-1 soil. The study was set up in a completely randomized design with three replications. After completely mixing the soil with the fertilizer, the soils were incubated under 33.3 kPa of water potential at room temperature. The pH, total soluble salts, nitrate nitrogen (NO3--N), ammonium nitrogen (NH4+-N) concentration, Bray No. 1 phosphorus (P) and Mehlich Ⅲ extractable potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn), copper (Cu) and zinc (Zn) of the soil were determined after 10, 20, 30, 40, 50, 60, 80, 100, 120, 150 and 180 days of incubation.The results indicate that with planting different crops and application of different amount of fertilizer in the two rotation systems did not influence soil characteristics significantly. The soil characteristics were changed owing to the long-term application of organic fertilizer. The accumulation of K, Ca, Mg, Mn, Cu, and Zn in soils also occurred after long-term application of organic fertilizer, which was applied on the basis of supplied sufficient N for growth of crops. With applying of organic fertilizer before incubation, the pH of soil of conventional farming system increased. The soluble salt content of organic fertilizer-treated soil was higher than that of chemical fertilizer-treated one. Ammonium- N of organic or chemical fertilizer-treated soil decreased during incubation period. The concentration of NO3--N of organic fertilizer-treated soil decreased sharply during the early period of incubation, however, it increased at the later period of incubation. At the final stage of incubation, the NO3-N concentration of organic fertilizer-treated soil was the lowest of the all treatments. Furthermore, increase in Bray No.1 P and Mehlich Ⅲ extractable K of organic fertilizer-treated soil was significant and that of chemical fertilizer-treated soil was not. Mehlich Ⅲ extractable Ca of the organic fertilizer treatment of conventional farming plot in the two rotation systems was higher than those of chemical fertilizer-treated one and the control. Application of organic fertilizer also increased the soil extractable Mg and extractable Mn of rotation system II. Application of organic fertilizer before incubation decreased Mehlich Ⅲ extractable Cu of conventional plot in the two rotation systems. Mehlich Ⅲ extractable Zn of organic fertilizer treatment was higher than those of chemical fertilizer-treated one and the control.
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