Application of image technology to simulate optimal frequency of automatic collection of volumetric soil water content data

• Published in: Agricultural water management Vol. 269; p. 107674
• Main Authors: Wang, Jian, Li, Xin, Zhang, Zhenggui, Li, Xiaofei, Han, Yingchun, Feng, Lu, Yang, Beifang, Wang, Guoping, Lei, Yaping, Xiong, Shiwu, Xin, Minghua, Wang, Zhanbiao, Li, Yabing
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2022
• Subjects: agricultural land; algorithms; computer software; Contour map; cotton; Image processing technology; information technology; microirrigation; Monitor time period optimisation; mulching; soil profiles; Volumetric soil water content; volumetric water content; water management; water stress; Monitor time period optimisation; Image processing technology; Contour map; Volumetric soil water content
• ISSN: 0378-3774; 1873-2283
• DOI: 10.1016/j.agwat.2022.107674

Volumetric soil water content (VSWC) monitoring is an important aspect of environmental monitoring of farmland. Accurate and real-time determination of the VSWC is important for crop drought stress diagnosis and smart irrigation. Image technology is commonly used in agricultural information technology. Based on image technology, we simulated the optimal frequency of the sensors to automatically collect VSWC data, thereby solving the problems of data redundancy and data analysis difficulties in real-time monitoring. In this study, a cotton field under mulched drip irrigation in 2018 was utilised as the research subject, 5TE sensors were arranged on the soil profile of the cotton field using the "grid method", and Voxler and Surfer software was used to model the VSWC data and draw contour maps. Image processing technology (image greyscale and image similarity comparison) was employed to determine the image algorithm suitable for contour map pre-processing and the best time period for VSWC monitoring. These results indicated that the contrast-limited adaptive histogram equalisation (CLAHE) greyscale algorithm is a suitable pre-processing algorithm for processing contour maps using image processing technology, and the best 5TE sensor data monitoring time period is every 10 h. This conclusion provides a theoretical reference for VSWC monitoring and water management in production. •Image technology can be used for VSWC data processing.•CLAHE is a suitable greyscale algorithm for VSWC contour maps.•The longest interval for acceptable VSWC data with 5TE was 10 h.