Plant growth and nutrient use efficiency of two native Fabaceae species for mineland revegetation in the eastern Amazon

The primary challenge of mineland revegetation is the establishment of species able to cope with low availability of nutrients, especially in steep slopes such as of mine pits. We evaluated plant growth response and nutrient use efficiency (NUE) of two promising native Fabaceae species (Dioclea apurensis—liana from metalliferous savannas; Bauhinia longipedicellata—tree from Amazon rainforest) from the Carajas Mineral Province, eastern Amazon-Brazil. Plants were grown separately in 2-kg pots filled with mining waste. Substrates were fertilized with nitrogen, phosphorus, potassium (NPK), lime, and micronutrients. The results showed increments on growth of both species when nutrients were applied to the mining waste. D. apurensis showed increases in leaf area, plant height, stem diameter, and shoot dry mass production when NPK or NPK + micronutrients were applied, while B. longipedicelata was responsive to application of NPK + lime or NPK + lime + micronutrients. Further, D. apurensis showed higher NUE than B. longipedicelata, especially at the lowest doses of N, P and K. These findings may indicate a substantial advantage of D. apurensis for mineland revegetation, as this species may require lower nutrient inputs, being, therefore, a more sustainable way to revegetate degraded areas.