Comprehensive Assessment of Soil Quality in Tea Garden of Longyan City

By taking the tea garden in Longyan City as the research object, the soil quality was comprehensively evaluated to provide the theoretical basis for the scientific fertilization of local tea trees and the safe utilization of cultivated land resources. The contents of soil organic matter, total nitrogen, available phosphorus, available potassium, available manganese, available zinc, available boron, available molybdenum, cadmium, mercury, arsenic, lead and chromium were selected as the evaluation indexes, and the Nemero index method and the modified Nemero index method were used to evaluate the soil fertility level and heavy metal content in soil, respectively, and the soil quality was comprehensively evaluated by using the weighted summation method. The results showed that the the available phosphorus and available zinc in the tea garden soil of Longyan City were at the very rich level. The soil organic matter, total nitrogen and available potassium were at the medium level. The available manganese was at the deficient level. The available boron and available molybdenum were at the extremely deficient level. The comprehensive fertility index of soil ranged from 0.94 to 1.97, with an average value of 1.48. Among the 31 monitoring sites, the contents of soil cadmium in 6 sites, soil mercury in 3 sites and soil lead in 5 sites were higher than the risk screening value of soil pollution in agricultural land. The comprehensive soil pollution index ranged from 0.24 to 1.44, with an average of 0.66. The soil fertility of tea garden in the study area was generally at a general level, and the heavy metal pollution was generally at a safe level. The comprehensive evaluation results showed that the comprehensive score of soil quality of tea garden in Longyan City was 0.69, which belonged to the “good” grade.