Improved soil moisture, nutrients, and economic benefits using plastic mulchs in balsa-based agroforestry systems.

ABSTRACT

The manufacture of wind turbine blades generally uses balsa wood as the base materials, and it is crucial to explore new regions for cultivating balsa trees to achieve carbon neutrality in the future. Xishuangbanna may be China's only area with a tropical climate suitable for the large-scale planting of balsa trees. The present study investigated the key soil elements influencing the growth of balsa plantations and the effects of different cultivation practices on soil environments and economic benefits in Xishuangbanna, China. We found that the height of balsa stems after growing 4 years reached 5.8 m; the increment of diameter at breast height (DBH) reached 27.7 cm and volume of balsa stems reached 196.0 m3 ha-1 in Xishuangbanna of China. It is of the utmost importance to improve the contents of soil exchangeable magnesium (Mg) and available phosphorus (P) for the growth of balsa trees, and exchangeable aluminium (Al) inhibited the growth of balsa trees. The practice of plastic film mulching not only improved soil moisture in the 40‒100-cm soil layer in the dry season and in the 0-60-cm soil layer in the rainy season but also enhanced soil nitrate nitrogen when compared with no plastic-mulching practice in balsa plantations. The comprehensive economic benefits of balsa/coriander/ginger/taro plantations were significantly improved by implementing plastic film mulching, as compared to balsa plantations. We conclude that balsa tree can be cultivated in Xishuangbanna, China, and its successful cultivation provides opportunities for China's wind power development.