A large amount of tropical forests of Xishuangbanna have been deforested and converted to rubber plantations. The application of nitrogen fertilizer and sulfur powder in rubber plantations may have caused soil acidification.
Researchers from Xishuangbanna Tropical Botanical Garden (XTBG) conducted a study to clarify the effects of the conversion of tropical forests to rubber plantations on soil acidification processes, exchangeable cations, exchangeable aluminum (Al), available copper (Cu), zinc (Zn), manganese (Mn) and iron (Fe).
They found that the conversion of tropical natural forests to rubber plantations accelerated soil acidification processes, significantly decreases soil exchangeable Ca, Mg, available Zn, Mn, and Fe, and increased soil exchangeable Al and available Cu.
Large losses of soil exchangeable Ca, Mg, and available Zn in the rubber plantations would limit plant growth. The release of large amounts of exchangeable Al in the rubber plantations not only decreased soil available P but also would threaten the safety of the surrounding environment.
The researchers considered concerning the accumulation of exchangeable Al and the rapid decrease of exchangeable Ca, Mg and available Zn in the topsoil layers of the rubber plantations.
They suggested that preventative practices (e.g., application of lime and biochar) should be used to reduce the levels of exchangeable Al and improve the levels of exchangeable Ca, Mg and available Zn.
The study entitled “The conversion of tropical forests to rubber plantations accelerates soil acidification and changes the distribution of soil metal ions in topsoil layers” has been published in Science of The Total Environment.
LIU Changan Ph.D
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, Yunnan, China