Abstract: To explore the characteristics of soil nutrients of citrus orchards with different parent materials, clarify the influence of soil parent materials on fertility, and provide theoretical basis for orchard management and precise fertilization, 217 citrus soils with five different parent materials were collected to analyze soil pH, and the contents of organic matter, macro, medium and trace elements. The results showed that the mean soil pH value in citrus orchard was less than 5.5, and the soil was acidic. Except for plate shale and limestone, organic matter of other parent materials was deficient. Quaternary laterite was rich in exchangeable calcium and magnesium, while other parent materials were poor. The contents of soil alkalihydrolyzable nitrogen, available zinc, boron and molybdenum in each parent material were suitable, while available potassium, available phosphorus, sulfur, iron, manganese and copper were excessive. Analysis of variance showed that all soil indices except available copper and zinc were significantly different among different parent materials. The contents of soil organic matter, alkalihydrolyzed nitrogen, available phosphorus, available potassium, and available iron, copper and molybdenum in plate shale were higher than those in other parent materials, while the contents of exchangeable calcium and magnesium were lower than those in other parent materials. According to the comprehensive scores of principal components, soil fertility of each parent material was as follows: plate shale > sandstone > quaternary laterite > river-lake alluvial sediments > limestone. With the extension of citrus planting years, soil fertility of plate shale, river-lake alluvial sediments, and limestone soil was extremely significantly improved, and that of quaternary laterite was significantly increased. Comprehensive analysis shows that soil nutrients developed in plate shale were the most abundant. Soil organic matter, alkali-hydrolyzed nitrogen, available potassium, available boron, available phosphorus, and available sulfur were important factors affecting fertility. Due to the differences of soil nutrients in different parent materials, orchard soil should be accurately managed in case of local conditions to ensure the sound development of orchards.

Key words: citrus orchard, soil parent material, soil nutrient, planting years.