Biochar for Sand-Based Rootzone Modification.

Sand-based turfgrass rootzones are limited in nutrient retention and water holding capacity.  Peat moss is often used to offset these deficiencies, but peat moss is prone to decomposition.  The decomposition of peat moss adversely affects the physical characteristics of the rootzone and health of the turfgrass.  Biochar, a co-product of the fast pyrolysis process used to produce bio-oil, may be able to provide the same benefits as peat moss while being less prone to decomposition.  In addition, because biochar is relatively stable over time, sand-based turfgrass ecosystems established with biochar may become a viable long term carbon sequestration vehicle. This study was conducted to evaluate the effects of biochar on turfgrass growth in sand-based rootzones and to quantify the physical effects biochar has on these rootzones.  Rooting depth of creeping bentgrass (Agrostis stolonifera L.), saturated hydraulic conductivity and soil water characteristic curves were determined for six volume-to-volume mixtures of sand and biochar ranging from 0% biochar to 25% biochar, increasing by 5% increments.   Preliminary data show that biochar has a slightly positive impact on overall rooting depth up to 10% biochar; biochar percentages beyond 10% decreased creeping bentgrass rooting depth.  Biochar appears to have a positive impact on creeping bentgrass growth when mixed at appropriate rates.  With further applicable research, biochar may prove a valuable amendment for sand-based turfgrass ecosystems.