Effects of magnetoelectric water irrigation combined with foliar iron fertilizer on the growth characteristics and iron absorption of spinach

Vegetable cultivation is highly profitable and can quickly generate earnings. The demand for vegetables is increasing daily compared with grain crops. However, the inefficient use of water resources and the lack of microelements in soil prevent improvements in vegetable quality and yield. This study conducted indoor pot experiments on spinach (Spinacea oleracea L.), including five concentrations of foliar iron (e.g., 0, 15, 30, 45, and 60 mg/L) under conventional water and magnetoelectric water irrigation conditions. This experiment was conducted to clarify the effect of the combined application of magnetoelectric water and foliar iron fertilizer on the growth characteristics and iron absorption patterns of spinach. The results demonstrated that magnetoelectric water combined with the application of 15 mg/L foliar iron fertilizer was the most effective combination. These results occurred by (1) increasing the available iron content in the soil while promoting the accumulation of total nitrogen in spinach leaves and (2) increasing the chlorophyll content and maximum net photosynthetic rate of spinach leaves. This resulted in a significant increase of 31.91 % in the aboveground fresh weight of spinach and an iron enrichment coefficient of 40.12 %. Additionally, the accuracy of the logistic growth and light response model to simulate the growth and light response process of spinach was greater than 0.98, indicating good fitting effects. The increase in chlorophyll content was the main factor promoting spinach growth and iron absorption, and the prediction model of spinach yield based on chlorophyll content was well fitting. These results provide theoretical references and technical support for promoting magnetoelectric water irrigation technology combined with foliar iron fertilizer to improve vegetable yields.