Abstract:
Soil acid buffer performance was studied with the coffee planting soils from Mangshi and Lujiangba, major producing area of Yunnan Province. To study pH buffer capacity and influencing factors, 7 coffee planting soil samples were collected with different initial pH values (pH=4.44~5.04). The results showed that the pH buffer capacities (pHBC) ranged from 13.8 mmol·kg
−1 to 25.0 mmol·kg
−1. Based on the sensitivity classification, 6 samples showed sensitive and 1 sample showed slightly sensitive to acid and alkali changes, which implied weak acid buffer performance of the studied soils. Statistics analysis suggested that there was a significant positive correlation between pHBC and organic matter, conductivity, exchangeable H
+, exchangeable acid, cation exchange capacity and maximum water holding capacity (
p<0.01,
n=21). The relationship between pHBC and the soil basic physical and chemical properties was analyzed by stepwise regression, which indicating that EC and CEC were the main factors affecting pHBC. In order to improve acid buffering performance of coffee planting soils and create a good soil ecological environment for high-quality coffee production, reasonable application of fertilizer and adjustment of soil physical and chemical properties should be adopted.