Global meta-analysis of plasma-activated water for improving crop establishment, productivity, and health

Plasma-activated water (PAW) has emerged as a promising eco-friendly technology and a sustainable alternative to chemical fertilizers in agriculture due to its role in plant growth, nutrition, and disease suppression. To comprehensively evaluate its effectiveness, a meta-analysis was conducted using published studies comprising diverse crops, experimental conditions, and PAW generation chemistry. Log response ratios (LnRR) and pooled estimates with 95% confidence intervals were calculated, and forest plots were generated for each response variable. Results revealed that PAW application significantly improved plant growth and pigment content (chlorophyll a, b, and c and carotenoids), along with total soluble solids (TSS), total soluble protein (TSP), ascorbate peroxidase (APX), catalase (CAT), superoxidase dismutase (SOD), and total phenolic content (TPC) supporting improved metabolic activity. Moreover, a significant reduction in disease incidence and severity under PAW application ensured enhanced plant defense responses. Plasma activation altered water chemistry by lowering pH and increasing electrical conductivity, nitrate, nitrite, H₂O₂, and oxidation-reduction potential (ORP), reflecting the stable presence of reactive oxygen and nitrogen species (RONS). This comprehensive meta-analysis indicates that PAW consistently improves plant growth, biochemical characteristics, yield, and disease resistance. The acidifying nature of PAW also influences soil microbial dynamics, potentially enhancing nutrient cycling and long-term soil fertility. Collectively, the findings support PAW application as a multifunctional strategy for advancing sustainable agriculture through improved plant performance. The integration of solar-powered irrigation systems with onsite PAW activation and water quality sensors demonstrates a scalable pathway for precise, resilient irrigation and nutrient delivery in agriculture.