Responses of the Growth Characteristics of Spinach to Different Moisture Contents in Soil under Irrigation with Magnetoelectric Water

Abstract

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.