Abstract:

In Henan Province, fluvo-aquic soil is the most widely distributed soil type with the largest area, and the main grain production area. Its fertility directly affects grain production. Based on the cultivated land quality survey in 2018, this study selected three counties of Zhecheng, Hua and Sui as the study area, and analyzed the current situation of fluvo-aquic soil fertility in the province. The results showed that the average values of soil pH, soil organic matter content, total nitrogen content, available phosphorus content, available potassium content were 8.2, 17.4 g/kg, 1.11 g/kg, 21.1 mg/kg and 141 mg/kg, respectively. K-means clustering analysis was conducted to divide soil nutrients’ content into four grades. The soil organic matter content in grade 1 to 4 was >23.6, 18.1-23.6, 12.2-18.1 and <12.2 g/kg, and the proportion of each grade was 8.0%, 37.1%, 41.3% and 13.6%, respectively. The soil total nitrogen content in grade 1 to 4 was >1.35, 1.09-1.35, 0.85-1.09 and <0.85 g/kg, and the proportion of each grade was 18.4%, 30.7%, 35.7% and 15.2%, respectively. The soil available P content in grade 1 to 4 was>61.9, 36.1-61.9, 18.3-36.1 and <18.3 mg/kg, and the proportion of each grade was 2.7%, 8.8%, 32.0% and 56.5%, respectively. The soil available K content in grade 1 to 4 was>256, 171-256, 110-171 and <110 mg/kg, and the proportion of each grade was 6.4%, 18.9%, 38.4% and 36.3%, respectively. The results of principal component analysis showed that soil total nitrogen, organic matter and available phosphorus were the main factors affecting soil fertility in fluvo-aquic soil region.

Key words: Henan Province, fluvo-aquic soil, soil organic matter, soil total nitrogen, soil available phosphorus, soil available potassium