Biochar Affects Macronutrient Leaching from a Soilless Substrate

Abstract

<jats:p>Byproducts of pyrolysis, known collectively as biochar, are becoming more common and readily available as ventures into alternative energy generation are explored. Little is known about how these materials affect greenhouse container substrates. The objective of this research was to determine the effect of one form of biochar on the nutrient retention and release in a typical commercial greenhouse container substrate. Glass columns filled with 85:15 sphagnum peatmoss:perlite (v:v) and amended with 0%, 1%, 5%, or 10% biochar were drenched with nutrient solution and leached to determine the impact of biochar on nutrient retention and leaching. Nitrate release curves were exponential and peaked lower, at later leaching events, and had higher residual nitrate release over time with increasing biochar amendment rate. This suggests that biochar might be effective in moderating extreme fluctuations of nitrate levels in container substrates over time. Peak phosphate concentration decreased with increasing biochar amendment rate, whereas time of peak release, girth of the peak curve, and final residual phosphate release all increased with increasing biochar amendment. Additional phosphate levels in leachates from biochar-amended substrates, in addition to the higher phosphate concentrations present in later leaching events, suggest this form of biochar as a modest source of phosphate for ornamental plant production. Although there was not sufficient potassium (K) from biochar to adequately replace all fertilizer K in plant production, increasing levels of this form of biochar will add a substantial quantity of K to the substrate and should be accounted for in fertility programs.</jats:p>

Evaluating On-demand Irrigation Systems for Container-grown Woody Plants Grown in Biochar-amended Pine Bark

“…Therefore, the reduction of bulk density in the 25% biochar amendment rate is a result of the addition of biochar, which is a lower density material (0.10 g · cm -3 ) compared with the pine bark substrate (0.24 g · cm -3 ). Reduction in bulk density was reported in other studies after biochar application to soilless substrates (Altland and Locke, 2012;Beck et al, 2011;Dumroese et al, 2011;Tian et al, 2012).…”

Biochar and Biosolids Increase Tree Growth and Improve Soil Quality for Urban Landscapes

“…Studies often report decreases in nutrient leaching with additions of BC due to its high adsorption capacity (Lehmann et al, 2003;Laird et al, 2010;Singh et al, 2010). Altland and Locke, (2012) found BC amendments to be effective at moderating extreme levels of nitrate in container substrates over time. We are aware of only one study that has examined nutrient leaching with ACT.…”

Dynamics in the Strawberry Rhizosphere Microbiome in Response to Biochar and Botrytis cinerea Leaf Infection

“…Biochar was found to act as a fertilizer in container-grown plants, i.e., as a source of nutrients for plant growth (Altland and Locke, 2013a; Locke et al, 2013), and interacted with the fertigation solution by retaining or releasing nutrients in a nutrient-specific way (Altland and Locke, 2012, 2013b). Studies show that adding biochar to growth substrate can not only enhance crop productivity and performance (De Tender et al, 2016), but can also reduce crop susceptibility to diseases (Meller Harel et al, 2012; De Tender et al, 2016).…”