| 【Objective】This study is to find out the soil nutrients status in citrus orchards in eastern Guangdong
Province and to provide scientific basis for balanced fertilization and nutrient regulation.【Method】Top soil (0-30 cm)
samples were collected from 28 citrus orchards in Puning City and Raoping City of eastern Guangdong Province, and pH,
soil organic matter (SOM) content and available nutrient contents were measured.【Result】The soil pH was between 3.21
and 6.01, with the average value of 4.72, and 60.71% samples were acid soil. The average content of SOM was 16.82 g/kg,
the contents of 78.57% samples were in the abundant level, which were high than 15.0 g/kg and suitable for citrus growth,
but none was rich in SOM ( ＞ 30.0 g/kg). The deficiency ratios of alkaline nitrogen and exchangeable calcium were 53.57%
and 50.00%, respectively. Especially, the deficiency of exchangeable magnesium and available boron was serious, and the
deficient and extremely deficient ratios reached 57.14%, 21.43%, and 32.14%, 67.86%, respectively. However, the situation
of soil nutrient contents lack such as available phosphorus, potassium, iron and copper was common, and their excessive
percentages were 78.57%, 78.58%, 96.43% and 89.29%, respectively. 【Conclusion】Most of citrus orchard soils in easternGuangdong Province were acidic, soil nutrients were imbalanced and the abundance of different nutrients were quite different.
The application of phosphorus, potassium fertilizers and fungicides containing copper should be controlled rationally, More
calcium, magnesium, boron and organic fertilizers should be used, and the application of lime for acid soil in the citrus orchards
contributes to improving soil nutrition and reducing the excess of iron． |
