Manganese and Zinc Foliar Applications Increase Nutrient Content and Mitigate Cadmium-Induced Growth Inhibition in Spring Wheat

Abstract

Wheat (Triticum aestivum L.) is one of the most important staple food crops, and its sustained production and nutritional security have attracted much attention. Cadmium, a heavy metal toxic to plants and humans, can enter wheat in various ways. Foliar fertilization can reduce the cadmium content in plants, but how different fertilizers reduce the cadmium toxicity of plants is still unclear. In this study, the effects of foliar application of fertilizers on spring wheat yield, cadmium accumulation, and trace element contents were studied by applying three kinds of fertilizers (multi-element compound fertilizer, manganese-zinc micro fertilizer, and foliar silicon fertilizer) to spring wheat planted in mildly and moderately cadmium polluted areas. The results showed that the yield of wheat when fertilized with multi-element compound fertilizer, manganese-zinc micro fertilizer, and silicon fertilizer increased by 17.1%, 15.7%, and 16.9%, respectively, compared with the control. In addition, all three foliar fertilizers reduced the cadmium content in wheat grains to below the standard value of food pollutants (≤0.1mg/kg), and significantly reduced the transport of cadmium from glume to grain, among which manganese-zinc micro fertilizer had the best effect, with a cadmium reduction rate of 41.7%. At the same time, manganese-zinc micro fertilizer significantly increased the absorption of trace elements in wheat organs. These results indicated that the foliar application of manganese-zinc micro fertilizer could be an effective way to increase wheat yield, inhibit cadmium accumulation, and increase nutrient absorption in mildly to moderately cadmium-polluted areas.