Application of Mycorrhiza to Low-pH Soil from from Ex-Clay Mining on the Growth of Jatropha (Jatropha curcas L.)

Clay is one of the main raw materials used in cement production and is obtained through mining activities. Such mining activities can cause land degradation, including a reduction in soil pH. Land rehabilitation can be carried out by using acid-tolerant plants, applying land engineering techniques, and introducing mycorrhizae. This study aimed to determine the effects of various planting-media treatments on the growth of Jatropha curcas and to identify the optimal land-engineering treatment for its growth. The planting-media treatments consisted of combinations of garden soil, post-mining soil, and mycorrhizae. Each planting-media treatment was replicated four times and observed for 12 weeks (60 days after planting). Plant growth parameters included plant height, number of leaves, leaf area, plant biomass, shoot-to-root ratio, transpiration rate, net assimilation rate, and mycorrhizal infection. The data were analyzed using one-way ANOVA, followed by a Tukey post-hoc test. The results showed that increasing the proportion of post-mining soil resulted in lower growth of Jatropha curcas. The best growth of Jatropha curcas was observed in the treatment consisting of 50% post-mining soil + 50% garden soil + mycorrhizae. Mycorrhizal infection was inversely related to the proportion of post-mining soil. As the proportion of post-mining soil increased, the level of mycorrhizal infection in Jatropha curcas decreased