Dynamic treads of soil chemical properties in citrus planting soil

In this experiment, potassium sulfate and monopotassium phosphate were used as the potassium source. Three potassium amount levels (31.96 g, 37.36 g and 48.16 g) were set. The urea and monopotassium phosphate were applied respectively as nitrogen and phosphate sources. The fertilizers were applied from March to July, and soil samples were collected before, during and after fertilization. Three-year-old of hybrid citrus variety ‘Kiyomi’ trees were the plant materials. The results showed that 48.16 g potassium was the optimum amount to improve the soil fertility by enhancing the content of alkaline nitrogen, available potassium and organic matter.