Biochar Ability to Provide and Retain Nutrients in a Kentucky Blue Grass System.

Wastewater biosolids contain nutrients that could be useful as a turf grass soil supplement. Research suggests biochar produced from these biosolids can decrease nutrient runoff and increase soil moisture for sandy soils. Nutrient addition (e.g. fertilization) can be a significant maintenance cost, especially since not all nutrients are absorbed by a plant system when fertilizer is applied to the soil.  Both nitrogen (N) and phosphorus (P) can be lost through runoff and leaching; and bacteria can remove bioavailable nitrogen from the soil system.  This research will further investigate the use of biochar in providing nutrients to turf grass as well as the ability of biochar to retain nutrients in the soil system. 

The six systems studied included sand alone, sand amended with 10% v/v biochar, sand amended with 10% peat, sand amended with 10-10-10 fertilizer, sand amended with 10% biochar and fertilizer, and sand amended with 10% peat and fertilizer.  Kentucky Blue grass (Poa pratensis L.) was the model plant for this study and data was collected on the treatments applied to 4 inch PVC planters for 4 months. Plant biomass growth was measured over the 4 months; leachate water and soil samples were collected twice and analyzed for nitrogen and phosphorus content.  The study focused on the P and N (ammonium and nitrate) nutrient concentration of leachate and soil and the nutrient uptake of the biomass. Field capacity of the growth mediums was also evaluated.  Preliminary results indicate that this biochar is as effective as fertilizer in supplying nutrients to Kentucky Blue grass in a sand system, but at the applied concentration does not retain nutrients as expected.