Green manure can be an auxiliary factor against dynamic photoinhibition in Dalbergia ecastophyllum (L.) young trees in areas impacted by mining.

Abstract

This study evaluated the efficiency of green manure (+GM) on PSII efficiency throughout the day in Dalbergia ecastophyllum. The experiment was carried out in a disabled clay extraction deposit, located approximately 30 km south of São Mateus city (Espírito Santo State, Brazil). Chlorophyll (Chl) index, Chl a fluorescence, and plant growth were measured in the summer, after 12 months of planting. +GM improved the photochemical performance of D. ecastophyllum, reducing the occurrence of photoinhibition throughout the day. +GM increased the photochemical quantum yield, the probability of a photon absorbed to move beyond quinone Q_A ^-, and the total Chl index, resulting in higher plant height and stem diameter (+11.7 and +2.2%, respectively). The number of active reaction centers per cross-section and the performance index of PSII values were unchanged throughout the day. Full recovery of both K and L-bands occurred at night. In contrast, plants growing with -GM had higher energy losses as heat. In conclusion, these results contribute to improving revegetation techniques, to create better conditions for the planting of native tree species in degraded areas.