LupinuspolyphyllusLindl. andRumex acetosellaL. effects on nutrient accumulation and microbial activity on tephra from the Puyehue–Cordón Caulle eruption (2011)

Abstract

AbstractThis study investigated the capacity ofLupinus polyphyllus(Leguminosae) andRumex acetosella(Polygonaceae) to promote nutrient accumulation and microbial activity on tephra from the volcanic eruption of the Chilean Puyehue–Cordon Caulle complex (Northern Patagonia) in June 2011. In December 2015, February 2016 and September 2016, we sampled (1) barren substrate (‘Barren’), (2) substrate underR. acetosella(‘R. ac. substrate’), (3) substrate underL. polyphyllus(‘L. po. substrate’), (4)R. acetosellarhizosphere substrate (‘R. ac. rhizosphere’) and (5)L. polyphyllusrhizosphere substrate (‘L. po. rhizosphere’) (n = 5). Soil properties (moisture, pH, electrical conductivity, organic C, available P, inorganic N and total N) and microbial activity (enzymatic activities) were assessed. ‘Barren’ presented the lowest moisture, organic C, total N and enzymatic activities. ‘R. ac. substrate’ and ‘L. po. substrate’ showed similar levels of organic C (0.23–0.30 g kg−1), and however,R. acetosellawas associated with lower inorganic N (‘R. ac. substrate’ = 0.7 and ‘L. po. substrate’ = 2.3 mg kg−1) whileL. polyphyllustended to promote higher total N, especially in the rhizosphere (‘R. ac. rhizosphere’ = 0.19 and ‘L. po. rhizosphere’ = 0.34 g kg−1). ‘L. po. substrate’ and ‘L. po. rhizosphere’ presented the highest enzymatic activities. After five years,L. polyphyllusandR. acetosellahave increased tephra organic C, total N and microbial activity, and however,L. polyphyllushas maintained the best substrate N availability.Abstract in Spanish is available with online material.