臺灣水田土壤肥力之特徵及其在數字分類上之地位(1).高屏地區沖積土及桃園紅壤與紅壤沖積土

Abstract

根據美國農部1938年農業年刊「土壤與人類」中所記載，土壤肥力(Soil fertility) 係意指：在光線、水分、溫度與土壤物理條件等環境因素均適合於作物生長之情況下，土壤能夠平衡地適時、適量供應作物所需要各種營養元素之能力。由此定義，我們可以了解土壤肥力除受環境因素影響外，復視下列因素而決定：(1)養分之有效性及其平衡狀態；(2)土壤之物理性質(如通透性、排水、保水力、質地等)；(3)土壤之化學物質(如pH、緩衝能力、交換能力、有毒物質等)；及(4)土壤之生化學性質(如微生物之分佈與活性、有機物質之性質及其存在量等)。故土壤肥力是上列因素之綜合表現結果。 We investigated 130 slate alluvial soils (34 soil series) and 43 sandstone-shale alluvial soils (17 soil series) selected from 7 townships of Kaohsiung-Pingtung region, 95 latosols and lateritic alluvial soils (21 soil series ) selected from 2 townships of Taoyuan Prefecture. 15 soil properties (namely, organic matter, silt %, clay %, pH, exchangeable-Ca, Mg, K, AI, cation exchange capacity, available P, K, Si, Zn, free-Fe and free-Mn) of surface soil and 21 soil properties (Those included 15 soil properties of surface soil plus silt %, clay %, and soil color near a depth of 60cm and 90cm below the surface soil, respectively) of soil profile were investigated and the numerical classification was made based on the fertility differences.