Biochar Effects on Soil–Plant Properties after Six Month Adaptation in Soil

Abstract

ABSTRACT Biochar (BCH) is one of the most promising amendments to improve soil quality and store carbon in soils. Vast majority of the studies utilized freshly produced materials and assess BCH effects immediately after soil amendment. The aim of this study was to investigate the influence of biochars aged six months with two soil types on soil physicochemical and biological properties along with plant growth. Soils from a protection zone of water sources and from an agricultural area were mixed with three different types of BCH. After six months of aging, lettuce (Lactuca sativa var. capitata) plants were grown on these soils in greenhouse. Plant aboveground and root biomass, soil physicochemical properties [pH, cation exchange capacity (CEC), total nitrogen (TN), soil organic carbon (SOC), and total phosphorus (TP)], and biological activities [fluorescein diacetate activity (FDA) and urease activities, soil respiration, and` humic and nitrogen index] were determined. Studied BCHs had slight influence on soil physicochemical parameters. pH was significantly increased by all BCH amendments: in Luvisol by 12.7% and in Fluvisol by 11.25% (by 1.1 times). SOC was augmented in both soil types with the addition of the third BCH type that corresponded to the initial BCH input. BCH aging in soil had no influence on CEC, TN, TP and soil microbial activities (FDA, urease, and soil respiration). Moreover, two BCHs did not influence plant growth, whereas the third BCH type had a negative impact, decreasing lettuce development by 62% in Luvisol and by 41% in Fluvisol relative to untreated control soils.