Assessing the performance of a novel plant food made from anaerobically digested dairy manure solids
Abstract
The dairy industry is integral to the economy of Vermont and also one of the leading causes of phosphorus (P) loading and associated water quality impairment in Lake Champlain. Anaerobic digestion technologies divert P from waterways and generate clean energy from methane gas capture, but fall short of regenerating P for reuse in agriculture. Emerging post-digestion solids recovery technologies have been shown to capture over 85% of P from digestate in the form of a concentrated, recovered P (RP) product. We conducted a greenhouse bioassay to compare a novel RP plant food with a popular organic market alternative (OMA). Seedlings of tomato (Solanum lycopersicum L.), pepper (Capsicum annuum L.), petunia (Petunia x hybrid), and marigold (Tagetes patula) were grown for four weeks in a soilless substrate amended with 0 – 12% v/v plant food. Plants grown in RP food had an average biomass similar to those grown in OMA. This suggests that developing a commercially viable RP food could convert a waste stream into a revenue stream, while also lessening P loads on waterways by allowing for ‘precision’ fertilization using sustainably recaptured nutrients.
Assessing the performance of a novel plant food made from anaerobically digested dairy manure solids
The dairy industry is integral to the economy of Vermont and also one of the leading causes of phosphorus (P) loading and associated water quality impairment in Lake Champlain. Anaerobic digestion technologies divert P from waterways and generate clean energy from methane gas capture, but fall short of regenerating P for reuse in agriculture. Emerging post-digestion solids recovery technologies have been shown to capture over 85% of P from digestate in the form of a concentrated, recovered P (RP) product. We conducted a greenhouse bioassay to compare a novel RP plant food with a popular organic market alternative (OMA). Seedlings of tomato (Solanum lycopersicum L.), pepper (Capsicum annuum L.), petunia (Petunia x hybrid), and marigold (Tagetes patula) were grown for four weeks in a soilless substrate amended with 0 – 12% v/v plant food. Plants grown in RP food had an average biomass similar to those grown in OMA. This suggests that developing a commercially viable RP food could convert a waste stream into a revenue stream, while also lessening P loads on waterways by allowing for ‘precision’ fertilization using sustainably recaptured nutrients.