Growth and Survival of Jatropha curcas in Marginal Soils using Vesicular-Arbuscular Mycorrhiza Root Inoculant (VAMRI)

Abstract

The use of Jatropha curcas seed oil is recently being explored in the production of alternative biodiesel fuel. Vast idle lands with marginal soils - acidic, lahar or heavy metal contaminated — are probable sites for large scale production of J. curcas. In the present study the growth and survival of J. curcas in these soils with or without VAM inoculation were determined. One-way ANOVA in a CRD design with VAMRI treatment and soil types as independent factors and growth parameters as dependent factors was used. Least Significant Difference (LSD) at a=0.05 was conducted to evaluate statistical difference between treatments. J. curcas generally responded positively to VAMRI inoculation in both stressed and unstressed soils. It survived in most soils except in excessively Cu contaminated mine soil, that is, Bagacay mine soil. At very high concentrations in the soil, Cu uptake is significantly higher in mycorrhizal plants leading to Cu toxicity. The survival of J. curcas in most soils is due to its inherent tolerance in marginal soils. In general, VAM inoculation improved nutrient uptake most particularly P in both stressed and unstressed soils. Most of these resources were invested in formmg new leaves and bigger leaf areas to improve photosynthesis.