Agricultural sustainability in many parts of the world is facing significant challenges due to water scarcity and the adverse effects of climate change. Agriculture uses 70 % of the total freshwater, and irrigation sustains 40 % of the global food supply. Various plant monitoring technologies and irrigation techniques were developed to improve the efficiency of agricultural water use. Although their benefits are widely acknowledged, conflicting findings and inconclusive results emerge when assessing their performances and effectiveness in monitoring plant water status. A systematic review using a rigorous protocol for research question formulation and eligibility criteria definition was conducted with the aim of assessing, from published literature, the performance of various plant (tree) based sensors for water stress monitoring. Initially, 496 articles were collected from four leading search engines for scientific peer-reviewed papers., the number of relevant manuscripts was narrowed to 124, using strict inclusion and exclusion criteria, from which meta-analysis was conducted and reported. Results showed that most studies were conducted in Spain and the USA, focusing on olive, peach, and almond cultivation. Crop Water Stress Index showed a better correlation with stomatal conductance (gs) (R2 = 0.76) and with leaf water potential (ΨL) (R2 = 0.75) compared to Xylem Water Potential (ΨS) (R2 = 0.6). Maximum Daily Shrinkage (MDS) showed a coefficient of determination with ΨS equivalent to 0.68. On the remote sensing side, the most commonly used indices are the Normalized Difference Vegetation Index (NDVI) (n=22), Photochemical Reflectance Index (PRI) (n=11), and canopy temperature (n =94) with better correlation with ΨS for PRI and thermal. However, the finding is not conclusive due to the complexity of plant water relations and the influence of other factors such as environmental conditions, canopy structure, nutrient deficiencies, and plant diseases.

中文翻译：

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基于植物和遥感的果园作物水分状况监测：系统评价和荟萃分析


由于水资源短缺和气候变化的不利影响，世界许多地方的农业可持续性正面临重大挑战。农业消耗了 70% 的淡水，灌溉维持了全球 40% 的粮食供应。开发了各种植物监测技术和灌溉技术，以提高农业用水效率。尽管它们的好处得到广泛认可，但在评估它们在监测植物水分状况方面的表现和有效性时，会出现相互矛盾的发现和不确定的结果。使用严格的方案进行研究问题制定和资格标准定义进行系统评价，目的是从已发表的文献中评估各种基于植物（树木）的传感器对水分压力监测的性能。最初，从四个领先的科学同行评审论文搜索引擎中收集了 496 篇文章，使用严格的纳入和排除标准，将相关手稿的数量缩小到 124 篇，从中进行和报告荟萃分析。结果显示，大多数研究是在西班牙和美国进行的，重点是橄榄、桃子和杏仁的种植。与木质部水势 （ΨS） （R2 = 0.6） 相比，作物水分胁迫指数与气孔导度 （gs） （R2 = 0.76） 和叶片水势 （ΨL） （R2 = 0.75） 的相关性更好。最大日收缩率 （MDS） 显示 ΨS 等于 0.68 的决定系数。在遥感方面，最常用的指数是归一化差值植被指数 （NDVI） （n=22）、光化学反射指数 （PRI） （n=11） 和冠层温度 （n =94），与 PRI 和热的 ΨS 相关性更好。 然而，由于植物水关系的复杂性以及环境条件、树冠结构、营养缺乏和植物病害等其他因素的影响，这一发现并不是决定性的。