Evaluation of Lime Requirement in Taiwan Acid Soils.

• Main Authors: Wang Jen-Chi, 王禎祺
• Other Authors: Sheng-Bin Ho
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/11448285494312419166

碩士 === 國立臺灣大學 === 農業化學研究所 === 87 === Strongly acidic soils greatly restrict the growth of most plants. The addition of lime raises the soil pH, eliminates the major problems of acid soils, and thus improves plant growth. However, adding excess lime causes soil nutrients imbalance is not desirable and is additional cost. The objectives of this study were to determine lime requirements of twenty five acid soils from Taiwan using various methods, including titration method, CaCO3 incubation method under three moisture conditions, and four buffer method, i.e., SMP method, Adams-Evans method, improved Woodruff method, and exchangeable acidity method; and to evaluate the most suitable methods used in Taiwan agricultural soils. Buffer-indicated lime requirements were relate to CaCO3 incubation-measured lime requirements through regression analysis. Lime requirements measured by incubation method under three moisture conditions decreased slightly in the order of field capacity incubation, alternately wetting and drying incubation and flooding incubation, and correlated well among each other. Lime requirements determined by the titration method were close to those by incubation method under field capacity and correlated well to those of all the three incubation methods. All of the four buffer methods underestimated lime requirements in high lime-required soils as compared to those by the incubation methods. The use of the relationship between soil pH and base saturation percentage from Taiwan agricultural soils ( pH ＝ 0.0316×) to correct lime requirements by Adams-Evans method had shown to be better applicability to Taiwan agricultural soils. Lime requirements determined by all the methods used in this study were correlated well among each other. The relationship between lime requirements and soil properties using stepwise procedure proposed the following empirical model: LR = 3.07 ×OM + 2.27 ×Exchangeable acid + 0.72 ×CEC — 5.40 ×pH + 0.79 ×DCB-Al + 17.15 , r2=0.95***, where LR is lime requirement in Mg CaCO3/ha, OC is organic carbon in g/kg, EA is exchangeable acidity in cmol(+)/kg, CEC is cation exchange capacity in cmol(+)/kg, DCB-Al is DCB extractable Al in g/kg. This empirical model can be use to predict lime requirement in Taiwan agricultural soils.