Studies on acidification and control of orchard soil in red earth region of Guangxi.
Jiang ZePu, Wei GuangBo, Meng YanCheng, Huang YuYi
Author Affiliation: Institute of Soil and Fertilizer, Guangxi Academy of Agricultural Sciences, Nanning 530007, China.
Southwest China Journal of Agricultural Sciences 16 : 90-94
Abstract : Four kinds of orchard (orange, litchi [Litchi chinensis], longan and mango) soil environment status in red earth region of Guangxi Province (China) were investigated and compared with data of the second soil survey. Results showed that orchard soil environment in red earth region of Guangxi was deteriorated. Orchard soil acidity of Guangxi was higher with an average pH of only 4.83, and acidic and strong acidic orchard with pH less than 5.5 accounted for 83% of the total. The highly acidic orchard soil with pH less than 4.5 accounted for 34% of the total sample number with the increase of 19% compared with that of the year 1980. The orchard soil of Guangxi was generally acidic. Among the four kinds of orchard, soil pH value of the orange orchard decreased most by 0.95 unit, and that of the litchi, longan and mango decreased by 0.89, 0.70 and 0.64 unit, respectively. Among three kinds of parent material, the soil pH value of Quaternary red soil dropped one unit, the soil pH value of granite and sand shale dropped 0.88 and 0.54, respectively. The acidification order (from heavy to light) of orchard soil in various regions of Guangxi province were: GX south>GX north>GX middle>GX east>GX west, compared with that of the year 1980. The factors that led to orchard soil acidification were mainly disequilibrium of fertilizer application, poor orchard management, and soil erosion due to high temperature and rainfall of Guangxi province. Some measures to prevent orchard soil acidification are suggested.