To investigate the effect of low amount of potassium application with magnesium hydroxide nanoparticles on the nutritional effect of cabbage and to improve the efficiency of potassium utilization. A pot experiment of cabbage was conducted at Southwest University using acidic purple soil. All treatments were applied with N 200 mg/kg and P_2O_5 100 mg/kg, and five treatments were applied: no potassium, low potassium (K_2O 75 mg/kg soil), moderate potassium (K_2O 105 mg/kg soil), and low potassium with MgOH nanoparticles 1.13 and 1.88 mg/kg soil. The yield, chlorophyll content, antioxidant capacity, nutrient uptake, potassium utilization efficiency and nutritional quality of cabbage were measured after 68 days of growth.
The yield of cabbage was increased by 21.5% when 0.3% (1.13 mg/kg soil) of total nitrogen, phosphorus and potassium fertilizer was applied. 8.9% and 4.3%~8.7%, respectively. The antioxidant capacity of cabbage was increased by 7.6%, 6.2% and 6.8%~20.0% for non-enzymatic antioxidants such as carotenoids, total phenols and flavonoids, respectively, and by 9.8%~18.8%, 10.7%~11.2% and 7.4%~9.9% for enzymatic antioxidants such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), respectively. and 7.4%~9.9%, respectively. The nutrient uptake of cabbage was promoted by the application of magnesium hydroxide nanoparticles, which increased the phosphorus and magnesium contents of cabbage by 3.8%~16.9%, 11.1%~24.9%, and the uptake of nitrogen, phosphorus, potassium and magnesium by 9.1%~10.2%, 13.2%~32.3%, 8.4%~14.4% and 26.6%~39.7%, respectively. efficiency and potassium utilization.