強酸性土壤石灰需要量空間分佈之推估與應用

Abstract

Strongly acidic soil is the main problem soil in Taiwan, liming has been suggested to be the most economical and useful practice to reclaim strongly acidic soils. However, the effect is determined by the kinds and the amount of lime materials used. The suitable liming practices are very important for managing strongly acidic soils. The objectives of this study were to determine the lime requirements of twenty-four strongly acid soils of Taiwan using the methods of incubation, reducing Al saturation to 10%, and three buffer methods (SMP-single, Woodruff-original and Woodruff-improved method, respectively). In addition, aregression analysis was also assessed to compare the effects among four different lime materials (agricultural lime, dolomite, oyster-shell powder, and silicate slag). Result showed that the suggested lime requirement of the strongly acidic soils can be calculated by using regression models developed by correlation between lime requirement(y) determined by reducing Al saturation to 10% and lime requirement determined by buffer method(x), such as y = 0.42 x1 -2.16 (R2 = 0.87, p<0.001); y = 1.05 x2 -2.33 (R2 = 0.84, p<0.001) and y = 0.73 x3 - 1.63 (R2 = 0.88, p<0.001), x1, x2, and x3 are the lime requirement determined by SMP-single method, Woodruff-original method and Woodruff-improved method, respectively. The capacity of rising soil pH is generally agricultural lime>dolomite>oyster-shell powder>silicate slag. In the other study in Ho-li, soil samples that took by grid sampling were used to study for lime requirement spatial distribution. The results showed that the least sampling size of this study area was 0.5-ha griding sampling. Furthermore, the spatial distribution of LR could be predicted by using ordinary kriging that the data of LR get from regression models. The application of this regression models was sampled from Da-du-shan soil with 0.5-ha griding sampling. The spatial distribution of LR in Da-du-shan soil was measured by regression models and predicted by using ordinary kriging. Afterward, the LR spatial distribution map was combined with the electronic map by geographic information system. According to the map, we can get the liming of the actual position which wanted to ameirolate and achieve the purpose of improvement quickly.

強酸性土壤為台灣主要的問題土壤，石灰施用已知為最經濟有效的方法，其質材之選用及用量之適當與否，將影響其改良效果。適當的石灰施用為管理強酸性土壤的重要課題。本試驗的目的在於，以直接培育法、降低鋁飽和度至10%法和三種不同緩衝溶液法(SMP-single、Woodruff-original和Woodruff-improved法)，分別測定台灣地區二十四種強酸性土壤的石灰需要量。另以迴歸方程式求取四種石灰質材間(農用石灰、白雲石粉、蚵殼粉和矽酸爐渣)的改良效果。另以迴歸方式求得降低鋁飽和度至10%法與不同緩衝溶液法間之石灰需要量關係式，以建立強酸性土壤之石灰需要量模式。結果顯示，推薦之強酸性土壤石灰需要量，可由緩衝溶液法的測值(x)，與降低鋁飽和度至10%所需的石灰量(y)間所建立的相關式來求得，如y = 0.42 x1 - 2.16 (R2 = 0.87, p<0.001)；y = 1.05 x2 - 2.33 (R2 = 0.84, p<0.001)及y = 0.73 x3 - 1.63 (R2 = 0.88, p<0.001)，其中x1、x2和x3為分別以SMP-single法、Woodruff-original法及Woodruff-improved法所測得之石灰量。石灰質材提昇土壤pH之能力一般為：農用石灰>白雲石粉>蚵殼粉>矽酸爐渣。另在后里地區的研究，乃以網格方式採土並探討石灰需要量的理分佈。結果顯示，以0.5公頃網格可得最少數的採樣點，另配合石灰需要量迴歸模式所求得之石灰需要量，再利用一般克利金法，可預測強酸性土壤之石灰需要量空間分佈，以作為全面改良強酸性土壤之依據。模式之應用係以0.5公頃網格採樣方式，採集大肚山區強酸性土壤，以SMP-single迴歸模式估測石灰需要量，利用克利金法推估石灰需要量分佈圖，並藉由地理資訊系統與電子地圖相結合，即可得到石灰需要量之空間分佈圖，藉由此圖，可以直接得知欲改良實際位置之強酸性土壤石灰用量，達成快速改良之目的。