|Title:||台灣若干土壤有機質分解、聚積之模擬及有機質肥料施用塞準之試定||Other Titles:||Modeling of Organic Matter Turnover in Some Taiwan Soils and Estimation of Criteria for the Application of Organic Manures||Authors:||陳琦玲
|Keywords:||土壤有機質;分解;模擬;Soil organic matter;Turnover;Modeling||Issue Date:||Dec-1995||Related Publication(s):||農業試驗所特刊第50號||Start page/Pages:||171-190||Source:||有機質肥料合理施用技術研討會專刊||Conference:||有機質肥料合理施用技術研討會||Abstract:||
This paper reviews changes of organic matter content in the soils of some long-term experiments conducted in Taiwan, where different rates of crops residues or organic manures had been applied continuously. The decompsition and accumulation of organic matter in the soils were simulated to the first order reaction and the model was used to estimate the input of organic manures required to maintain different levels of organic matter in the soils.
The experiments consist of a 48-year field trial with the cropping system of two crops paddy rice per year in Taipei, a 14-year field trial with the cropping system of rice-rice-soybean per year in Pingtung and a 9-year field trial with the cropping sy stem of 2-3 crops soybean per year in Taiwan. For the sake of comparison, a 60-year field trial with the cropping system of one crop paddy rice per year in Saitama, Japan and a 9-year field trial with the cropping system of onion-cabbage per year in Kanaga Wa, Japan were also reviewed.
The results indicate that soil organic matter can maintain higher generally in the Temperate than in the Tropics, and in paddy than in upland. The long-term application of chemical fertilizer did not deplete the content of soil organic matter but even increase slightly compared to the soil without application of fertilizers. A stablized content (3.0%) of organic matter was, in fact, maintained in the soil without application of fertilizer in this paddy soil; the rice stubbles and roots remained in the s oil after the harvests were enough to maintain this level of organic matter without any tendency of depletion. On the other hand, the long-term application of green manure did not increase the content of soil organic matter as significantly as that of comp ost did, although it did increase slightly higher than the soil with the application of chemical fertilizer. Apparently, the increase of soil organic matter through the application of organic manure is more difficult in Taiwan than in Japan due to its high er rate of decomposition. This characteristics, however, is advantageous for agricultural land to act as disposal places for the harmless organic waste produced by animal husbandry. The reasonable rate of application, however should be evaluated so that en vironmental impact will be minimized.
According to the results of the experiments and simulation analysis, the continuous application of 17Mg/ha/year (fresh weight basis) of farm yard manure for 70 years is required to raise soil organic matter from the level of 3.5% to 4.5%, both at nearly equilibrated state, in the paddy field of Taipei. The rate of N release at equilibrated status maintaining 4.5% organic matter is 180Kg N/ha/year. On the other hand, the continuous application of 110Mg/ha/year (fresh weight basis) of bagasse filter cake compost for 30 years 15 required to raise soil organic matter from the level of 1% to 2%, both at nearly equilibrated state, in the upland field of Tainan • The rate of N release at equilibrated state maintaining 2% organic matter is 740Kg N/ha/year. The 1ong-term application apparently will cause pollution to the environment.
|Appears in Collections:||農業化學組|
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