Influence of Biochar on Soil pH, Water Holding Capacity, Nitrogen and Carbon Dynamics:
The thermo-chemical conversion (pyrolysis) of plant biomass is being evaluated by ARS for its potential to produce second generation liquid biofuels and the co-product biochar, which can be used as a soil amendment. Biochar was found to improve soil pH, water holding capacity (WHC) and soil C pools. In irrigated production systems, appropriate choice of biochar feedstock could increase soil WHC and reduce either the frequency or amount of irrigation.
Remediation of Phosphorus from Dairy Lagoon Waters using Biochar:
Estimates of animal manures produced in the United States by feedlot cattle, dairy cattle and swine exceeds 78 million tons annually. ARS-Prosser developed a strategy to utilize dairy waste as an alternative energy and fertilizer source. The fiber component exiting an anaerobic digester was used as a feedstock to produce bio-gas or bio-oil under low temperature pyrolysis. The co-product, biochar was applied to dairy waste water to remove nutrients. Our approach resulted in the removal of >32% of the P from the dairy effluent. Dairies in Washington State could produce 230,000 tons of biochar a year from manure.
Phosphorous Uptake by Potato from Biochar Coated with Anaerobic Digested Effluent:Removal of nutrients by biochar from dairy storage lagoons and use as a supplemental fertilizer off site is a beneficial strategy to reduce nutrient contamination around dairies and supply nutrients in potato production. Biochar amended with dairy effluent applied at 2.5 T per acre maintained recommended soluble P levels (1000 ppm) in Ranger and Umatilla potato variety petioles through 60 days after emergence. Biochar amended-P from dairy lagoons can be used successfully as a P fertilizer supplement in potato production. Secondary benefits of biochar additions improve soil pH, water holding capacity and soil C pools.