Guadua chacoensis BAMBOO BIOCHAR (POACEAE, BAMBUSEAE) AFFECTED HORTICULTURAL SPECIES IN A SALINE-ALKALINE SOIL

ABSTRACT Biochar is being used with increasing frequency as a soil remediator. However, its impact depends on soil limitations, biochar source and concentration applied. We studied Guadua chacoensis bamboo biochar as a saline-alkaline soil amendment. Aqueous solutions with 0, 2.5 and 5% of bamboo biochar (BC) were used to determine their influence on seed germination rate and radicle length in two horticultural species moderately tolerant to salinity and alkalinity: arugula (Eruca sativa) and radish (Raphanus sativus). Also, we amended a saline-alkaline soil with 0, 0.5 and 2.5% of BC to evaluate its effect on plant height, leaf and root biomass of both horticultural crops. The application of 2.5 and 5% BC solution decreased arugula germination in 3.14% and 5.2%, respectively, compared to 0% BC. The addition of BC decreased radicle length in both species and such reduction was more significant with the higher BC concentration. The addition of 0.5% and 2.5% BC as amendment in a saline-alkaline soil decreased arugula height in 27.32% and 50.33%, respectively, compared to 0% BC, resulting in smaller plants with less leaf and root biomass. The BC amendment did not affect leaf biomass, but 2.5% BC reduced root biomass in 53.85% compared to 0% BC. These results seem to be influenced not only by the BC inherent characteristics but also by the increase in soil pH, caused by the addition of biochar. Further studies may evaluate the impact of BC addition with different properties on saline-alkaline soils, and its use as an amendment in the remediation of acid soils.