A Sentinel-2 Image-Based Irrigation Advisory Service: Cases for Tea Plantations
In this study, we aim to develop an inexpensive site-specific irrigation advisory service for resolving disadvantages related to using immobile soil moisture sensors and to the differences in irrigation needs of different tea plantations affected by variabilities in cultivars, plant ages, soil heter...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-05-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/13/9/1305 |
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| author | Yi-Ping Wang Chien-Teh Chen Yao-Chuan Tsai Yuan Shen |
| author_facet | Yi-Ping Wang Chien-Teh Chen Yao-Chuan Tsai Yuan Shen |
| author_sort | Yi-Ping Wang |
| collection | DOAJ |
| description | In this study, we aim to develop an inexpensive site-specific irrigation advisory service for resolving disadvantages related to using immobile soil moisture sensors and to the differences in irrigation needs of different tea plantations affected by variabilities in cultivars, plant ages, soil heterogeneity, and management practices. In the paper, we present methodologies to retrieve two biophysical variables, surface soil water content and canopy water content of tea trees from Sentinel-2 (S2) (European Space Agency, Paris, France) images and consider their association with crop water availability status to be used for making decisions to send an alert level. 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 that make up the service, from downloading an S2 image from the web to alert level text messaging, are automated and can be completed before 7:30 a.m. the next day after an S2 image was taken. Therefore, the service is operated cyclically, and corresponds to the five-day revisit period of S2, but one 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 t ha<sup>−1</sup>) per irrigation event is recommended. The service is now available to over 20 tea plantations in the Mingjian Township, the largest tea producing region in Taiwan, free of charge since September 2020. This operational application is expected to save expenditures on buying irrigation water and induce deeper root systems by decreasing the frequency of insufficient irrigation commonly employed by local farmers. |
| first_indexed | 2024-03-10T11:38:49Z |
| format | Article |
| id | doaj.art-ac5b1bf30f9a4d8a868c3b3d07d9909c |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-10T11:38:49Z |
| publishDate | 2021-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-ac5b1bf30f9a4d8a868c3b3d07d9909c2023-11-21T18:42:20ZengMDPI AGWater2073-44412021-05-01139130510.3390/w13091305A Sentinel-2 Image-Based Irrigation Advisory Service: Cases for Tea PlantationsYi-Ping Wang0Chien-Teh Chen1Yao-Chuan Tsai2Yuan Shen3Department of Soil and Environmental Sciences, College of Agriculture and Natural Resources, National Chung-Hsing University, Taichung City 402, TaiwanDepartment of Agronomy, College of Agriculture and Natural Resources, National Chung-Hsing University, Taichung City 402, TaiwanDepartment of Bio-Industrial Mechatronics Engineering, College of Agriculture and Natural Resources, National Chung-Hsing University, Taichung City 402, TaiwanDepartment of Soil and Environmental Sciences, College of Agriculture and Natural Resources, National Chung-Hsing University, Taichung City 402, TaiwanIn this study, we aim to develop an inexpensive site-specific irrigation advisory service for resolving disadvantages related to using immobile soil moisture sensors and to the differences in irrigation needs of different tea plantations affected by variabilities in cultivars, plant ages, soil heterogeneity, and management practices. In the paper, we present methodologies to retrieve two biophysical variables, surface soil water content and canopy water content of tea trees from Sentinel-2 (S2) (European Space Agency, Paris, France) images and consider their association with crop water availability status to be used for making decisions to send an alert level. 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 that make up the service, from downloading an S2 image from the web to alert level text messaging, are automated and can be completed before 7:30 a.m. the next day after an S2 image was taken. Therefore, the service is operated cyclically, and corresponds to the five-day revisit period of S2, but one 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 t ha<sup>−1</sup>) per irrigation event is recommended. The service is now available to over 20 tea plantations in the Mingjian Township, the largest tea producing region in Taiwan, free of charge since September 2020. This operational application is expected to save expenditures on buying irrigation water and induce deeper root systems by decreasing the frequency of insufficient irrigation commonly employed by local farmers.https://www.mdpi.com/2073-4441/13/9/1305DSS for irrigationwater use efficiencysoil moistureSentinel-2tea |
| spellingShingle | Yi-Ping Wang Chien-Teh Chen Yao-Chuan Tsai Yuan Shen A Sentinel-2 Image-Based Irrigation Advisory Service: Cases for Tea Plantations Water DSS for irrigation water use efficiency soil moisture Sentinel-2 tea |
| title | A Sentinel-2 Image-Based Irrigation Advisory Service: Cases for Tea Plantations |
| title_full | A Sentinel-2 Image-Based Irrigation Advisory Service: Cases for Tea Plantations |
| title_fullStr | A Sentinel-2 Image-Based Irrigation Advisory Service: Cases for Tea Plantations |
| title_full_unstemmed | A Sentinel-2 Image-Based Irrigation Advisory Service: Cases for Tea Plantations |
| title_short | A Sentinel-2 Image-Based Irrigation Advisory Service: Cases for Tea Plantations |
| title_sort | sentinel 2 image based irrigation advisory service cases for tea plantations |
| topic | DSS for irrigation water use efficiency soil moisture Sentinel-2 tea |
| url | https://www.mdpi.com/2073-4441/13/9/1305 |
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