Abstract: This review aimed to examine the application potential of triboelectric nanogenerators (TENGs) in agricultural micro-energy (ME) harvesting and self-powered sensing. It focused on whether weak, low-frequency, and distributed energy sources in agricultural environments could be converted into usable electrical energy, and whether TENG-based devices could support battery-free monitoring of key environmental and biochemical parameters. The review also identified major technical limitations that affected field deployment and summarized possible development directions for smart agriculture. Recent studies on TENG-based agricultural energy harvesting and sensing were analyzed. The working principles of contact electrification and electrostatic induction were summarized, and representative device structures, material designs, and hybrid configurations were compared. Applications were classified into ME harvesting from wind, raindrops, and water flow, and self-powered sensing for wind speed, wind direction, flow behavior, and nutrient concentration. Reported output performance, sensing capability, stability, and system integration were used as the main evaluation criteria. The reviewed studies showed that TENGs had provided an effective technical route for collecting irregular agricultural energy and converting mechanical interaction into electrical signals. In wind energy harvesting, rotary, swing-structured, blade-based, and direction-adaptive devices were developed to improve low-speed startup, airflow adaptability, and output stability. Some systems reached a volumetric charge density of 49.39 millicoulombs per cubic meter and drove eight wireless sensors simultaneously at a wind speed of six meters per second. Direction-adaptive hybrid devices further achieved an output power of 177.26 milliwatts under the same wind speed, indicating better suitability for open farmland, greenhouse ventilation, and other variable wind conditions. For raindrop and water-flow energy, liquid-solid TENGs, droplet-based generators, water-tube structures, and waterwheel hybrid systems were used to harvest energy from rainfall, irrigation flow, and moving liquid interfaces. Their performance was improved through surface modification, hydrophobic materials, optimized electrode structures, and coupling with electromagnetic generators. These designs not only generated electrical output but also supported low-power sensing, wireless transmission, and liquid-state monitoring. In self-powered sensing, TENGs converted external mechanical or liquid disturbances directly into measurable electrical signals. Reported sensing targets included wind speed, wind direction, liquid flow rate, droplet behavior, leakage, blockage, and nutrient concentration. Wind-related sensors monitored airflow within the range of three to five meters per second, while biochemical sensing devices detected urea concentrations from zero to five millimoles per liter. Microfluidic and droplet-based devices also showed sensitivity to bubble state, liquid motion, bacterial targets, and chemical composition. These results indicated that TENG-based sensors had advantages in simple structure, active signal generation, low power demand, and compatibility with distributed monitoring nodes. However, their output was still affected by humidity, surface contamination, material wear, environmental disturbance, and load matching. Output fluctuation, long-term durability, packaging reliability, and power management remained key barriers to agricultural application. TENGs showed clear potential for agricultural ME harvesting and self-powered sensing, especially in scenarios where conventional batteries were difficult to replace or maintain. Future studies should improve structural robustness, material stability, environmental resistance, and output consistency. Power management circuits, energy storage modules, and low-power wireless communication units should be integrated with TENG devices. More complete sensing systems that combined energy harvesting, signal processing, data transmission, and field calibration were needed to promote practical smart agriculture applications.