Spinach (Spinacia oleracea L.) is a worldwide vegetable crop with rich nutritional value, and drought is the main factor restricting its growth. Magnetized water and de-electronated water have shown potential for improving yield and quality in some crops. To assess the influence of magnetized-de-electronated water (denoted magnetoelectric water) on the growth characteristics of spinach, five soil moisture gradients were developed, including 45–55%, 55–65%, 65–75%, 75–85%, and 85–95% of field capacity (FC). The results demonstrated that the influence of irrigation by magnetoelectric water on the growth of spinach was obvious. All the spinach indicators with each soil moisture gradient under irrigation by magnetoelectric water were higher than those of irrigation by conventional water, including the fresh weight of shoots, chlorophyll content, and the total nitrogen content in the leaves. In particular, the improvement in fresh weight of shoots and the total nitrogen contents in the leaves had the highest values, as demonstrated by increases of 52.26% and 25.87%, respectively, under 65–75% of the gradient of FC. Additionally, the fitting results of the photo response curve by different light response models varied. The modified rectangular hyperbolic model was the most accurate for all the treatment groups and thus was the optimized model for the photosynthetic characteristics of spinach under irrigation by magnetoelectric water analysis. The parameters of the photo response curve showed that the dark respiration rate, apparent quantum efficiency, light saturation point, and maximum net photosynthetic rate all increased following irrigation by magnetoelectric water with different soil moisture gradients compared with conventional water irrigation. These research results can provide new technical support for improving the water use efficiency of irrigation water and increasing vegetable production.

The foliar application of biostimulants at specific concentrations under magnetic–electric water irrigation has a positive effect on water and fertilizer use efficiency and yield of cotton, which is crucial for green and sustainable agricultural development. As a new type of fertilizer, biostimulants have demonstrated remarkable effects in improving crop yield and quality by enhancing nutrient uptake, promoting plant growth, and increasing resilience to environmental stress. In this study, the effects of magnetic–electric-activated water irrigation and foliar biostimulant application on cotton growth and yield were investigated, with the aim of understanding the underlying mechanisms. The field experiment included various irrigation treatments (brackish water, fresh water, magnetic–electric brackish water, and magnetic–electric fresh water) and biostimulant concentrations (1600, 1200, 800, 400 times dilution, and no spraying). SEM analysis indicated that under magnetoelectric water irrigation, the foliar application of biostimulants enhances physiological growth of cotton, improving the water and nutrient uptake efficiency, and thereby increasing yield. Specifically, the effective boll number and single boll weight under magnetic–electric fresh water irrigation with an 800 times biostimulant concentration increased by 21.84–48.78% and 5.50–18.91%, respectively, compared to the no-spraying treatment. The seed cotton yield rose by 16.61–38.63%, water-use efficiency improved by 24.35%, the harvest index reached 0.33, and nitrogen absorption increased by 76.21%. Thus, integrating magnetic–electric water irrigation with foliar biostimulants offers a theoretical and technical foundation for advancing green, high-quality agriculture and sustainable production.

The lack of trace element iron has become a key factor restricting vegetable yield and quality improvement. To address the low production efficiency of water–fertilizer coupling in agricultural production, we used a combination of experimental research, theoretical analysis, and mathematical modeling to systematically determine the effects of magneto-electric water irrigation with iron application on spinach growth and physiology, its yield and quality, and soil water transport characteristics. Compared with conventional water irrigation, under magneto-electric water irrigation, the water volume and applied iron concentration average increased the total accumulation of nitrogen, carbon, and iron in the aboveground part of spinach by 3.71%, 10.16%, and 14.14%, respectively, and the aboveground part of spinach had the highest total accumulation of nitrogen and carbon when irrigation water was 3300 m³ ha⁻¹ and iron fertilizer application at 0.15%. Additionally, magneto-electric water irrigation increased spinach aboveground fresh weight and soluble sugar and protein content by an average of 13.34, 18.26, and 11.61%, respectively. Based on a comprehensive quantitative evaluation and analysis of aboveground nutrient accumulation in spinach, aboveground fresh weight, water use efficiency, and soluble sugar and protein content, we determined the optimal irrigation water and iron fertilizer application for spinach growth.