坡地果園經營對水源水質之影響－苗栗卓蘭食水坑梨園溪流水質偵測

THE QUALITIES OF STREAM FLOW INFLUENCED BY PEAR ORCHARD MANAGEMENT ON SLOPE LANDS

10.29417/JCSWC.198503_16(1).0005

詹連昌(L.C. Chan)；丁昭義(J.Y. Ding)

中華水土保持學報

16卷1期（1985 / 03 / 01）

40 - 59

繁體中文

台灣山坡地之果園面積相當龐大，部份鄰近水源地區，所以果園之經營，如鋤草、施肥、噴農藥等活動，會有直接影響水源水質之可能。本研究之目的，係探討果園之經營，降雨量與水源水質之關係，可供日後山坡地開發的果園對減少水質污染工作之參考。本研究在苗栗卓蘭鎮食水坑92公頃試驗地設四個取樣站，另選一小面積果園為施藥區，經調查、分析所得結論如下：一、食水坑果園與林地之水樣中，其中含氮、含磷以及含鉀量，均有因降雨而增加之趨勢。而林地之土壤肥力之流失遠較果園者為小，是故果園之經營若能加以良好的地表覆蓋及良好水土保持處理，則可防止泥沙之沖刷與減少土壤肥力之損失。二、噴施農藥後，若適逢降雨則有助於將果樹上之農藥流失至地面，甚至污染水源水質，且流失量為數不少。梨樹噴施大生45及鋤蟎丹，為期一個月內，噴三次，在雨季中農藥之流失率達35%～46%，若果園經營有良好的地表覆蓋，均有助於降低農藥之汙染水質。三、日雨量大小為影響山坡地水源水質的主要因素，通常晴天或小雨並不影響水質，但一般言之，日雨量達10公厘以上時，則水中所含成分有顯著變化而影響水質。

The area of soopeland orchards near the head of water sources is vast in Taiwan. Quality of surface water from agricultural land is extremely variable because it is influenced by soil, vegetation, and cultural practices. The purposes of this study were to ivestigate the effect of management of orchard and precipitation the water quality and to provide a basic reference for developing slope land. The stream waters from four sampling stations at Su-Sguei-Keng watershed in Cholan and samples of throughfall and stem-flow from pear trees after being applied with pesticide at small experimental block were gathered and analysed. The results of this study are summarized as follows: 1. In general, the concentrations of total dissolved N, P and K in surface water from orchard and forest land tend to be high as rainfall increase. However, nutrient losses from forest land is less than those from agricultural production regions. Therefore, good conservation practices and vegetation cover could decrease soil and nutrient losses from cultivated slope lands. 2. Rainfall promotes pesticide leaching from tree with a significant amount which may contaminate the surface water. About 35%-46% of Dithan M-45 and Plictran which applied three times within one month is lost from pear trees during raining. But good management and vegetation cover on orchards could lower the degree of contamination of pesticide on water quality. 3. The amount of daily precipitation is the most important factor influencing the water quality of slope land. The dissolved chemical composition of water flowing from agricultural land is very variable and affect water quality as daily rainfall over 10mm level.