生態農業：農業精準栽培管理技術開發【土壤環境科學系申雍教授】
| 論文篇名 | 英文：A Sentinel-2 image-based irrigation advisory service: cases for tea plantations 中文：基於 Sentinel-2 衛星影像的灌溉諮詢服務：茶園案例 |
| 期刊名稱 | Water |
| 發表年份,卷數,起迄頁數 | 2020, 376, no.114528 |
| 作者 | Wang, Yi-Ping; Chen, Chien-Teh; Tsai, Yao-Chuan; Shen, Yuan(申雍)* |
| DOI | 10.3390/w13091305 |
| 中文摘要 | 本文旨在開發一種廉價的特定地點灌溉諮詢服務，該服務可以解決與使用固定土壤濕度傳感器的缺點以及不同茶園受栽培品種、植物年齡、土壤異質性、 和不同管理措施干擾的影響。在本文中，我們提出了從 Sentinel-2 (S2) 衛星影像中反演茶樹表層土壤含水量和冠層含水量的方法，以及如何將這兩個生物物 理變量與用於確定要發送之作物可用水分狀態警報級別關聯性，同時應用既往的降水記錄作為輔助信息，以幫助確定或修改警報級別。一旦確定了每個目 標茶園的警報級別，就會通過簡訊發送給相關的農民。該服務的所有流程，從網路下載 S2 衛星影像到警報級別的簡訊消息，都已自動化，並且可以在拍攝 S2 衛星影像後的第二天早上 7:30 之前完成。因此，該服務是對應於 S2 的 5 天回訪週期循環運行的，但比 S2 衛星影像獲取日期晚 1 天。由於涉及的複雜 性，本研究尚未估計每個特定地點茶園所需的灌溉水量，但建議每次灌溉事件採用單一灌溉率（300 噸 ha-1）。從 2020 年 9 月起，已針對台灣最大產茶區名 間鄉 20 餘家茶園免費開通此項服務，預計可節省購買灌溉用水的開支，減少當地農民頻灌的習慣，並誘導茶樹根系更深入土壤。 |
| 英文摘要 | This paper aims to develop an inexpensive site-specific irrigation advisory service that can resolve the disadvantages related to using immobile soil moisture sensors and the differences in irrigation needs of different tea plantations affected by their variabilities in cultivars, plant ages, soil heterogeneity, and management practices. In the paper, we present methodologies to retrieve surface soil water content and canopy water content of tea trees from Sentinel-2 (S2) images and how to associate these two biophysical variables with crop water availability status used in determining the alert level to be sent. Precipitation records are used as auxiliary information to assist in determining or modifying the alert level. Once the site-specific alert level for each target plantation is determined, it is sent to the corresponding farmer through text messaging. All the processes make up the service, from downloading S2 image from the web to alert level text messaging, are automated and can be completed before 7:30 am the next day after an S2 image was taken. Therefore, the service is operated cyclically, corresponds to the 5-days revisit period of S2, but 1-day behind the S2 image acquisition date. However, it should be noted that the amount of irrigation water required for each site-specific plantation has not yet been estimated because of the complexities involved. Instead, a single irrigation rate (300 Tons ha-1) per irrigation event is recommended. The service is now available to over 20 tea plantations in the Ming-Jian Township, the largest tea-producing region in Taiwan, free of charge since September 2020. This operational application is expected to save the expenditures on buying irrigation water and induce deeper root systems by decreasing the frequency of insufficient irrigation commonly employed by local farmers. |
| 發表成果與本中心研究主題相關性 | 茶園灌溉的水電費約占直接生產成本的1/5，且茶農常有過於頻繁灌溉的操作習性。本研究開發結合專家知識、遙測影像和中央氣象局降雨紀錄及預報資 訊，每5天透過自動發送簡訊的方式，提供茶園是否需要灌溉的資訊，不僅可協助茶農節省灌溉費用，同時能節省寶貴的水資源。 |
