Unlocking the potential of carbon dots in agriculture using data-driven approaches

The utilization of carbon dots (CDs) in agriculture to enhance plant growth has gained significant attention, but the data remains fractionated. Systematically integrating existing data is needed to identify the factors driving the interactions between CDs and plants and strategically guide future research. Articles reporting on CDs and their effects on plants were searched based on inclusion and exclusion criteria, resulting in the collection of 71 articles comprising a total of 2564 data points. The meta-analysis reveals that the soil and foliar application of red-emitting bio-derived CDs at a low concentration (<10 ppm) leads to the most beneficial effects on plant growth. Random forest and gradient boosting algorithms revealed that the size and dose of CDs were important factors in predicting plant responses across multiple aspects (CDs properties, plant properties, environmental factors, and experimental conditions). Specifically, smaller sizes are more favorable to growth indicators (GI) below 6 nm, nutrient and quality (NuQ) at 3-6 nm, photosynthesis (PSN) below 7 nm, and antioxidant responses (AR) below 5 nm. Overall, our analysis of existing data suggests that CDs applications can significantly improve plant responses (GI, NuQ, PSN, and AR) by 10-39 %. To unlock the full potential of CDs, customized synthesis techniques should be employed to meet the specific requirements of different crops and climate condition. For example, we recommend the synthesis of small CDs (<7 nm) with emission peak values falling within the range of 405-475 and 610-670 nm to enhance plant growth. The global prediction of plant responses to CDs application in future scenarios have shown significant improvements ranging from 17 to 58 %, suggesting that CDs have widespread applicability. This novel understanding of the impact of CDs on plant response provides valuable insights for optimizing the application of these nanomaterials in agriculture.