The effect of fast pyrolysis biochar made from poultry litter on soil properties and plant growth

Little is known about the effect of biochar created from poultry litter on soil properties and plant growth. Five studies were conducted using biochar made by the fast pyrolysis of poultry litter. Two were greenhouse studies and three were field studies. The greenhouse studies were conducted with a sandy loam soil and a silt loam soil. First, lettuce (Lactuca sativa L) seeds were germinated in the greenhouse across biochar incorporation rates from 0 to 100%, and secondly a trial was conducted in which green peppers (capsicum annum L) were grown in soils with up to 5% biochar by weight. Elemental analysis was completed on the biochar and the soils were analyzed for bulk density (BD), water holding capacity (WHC), pH, cation exchange capacity (CEC), soluble salts (SS) and extractable nutrients. The field studies all used the rates of 0, 4.5, and 9 Mg ha-1 biochar and the rates were applied in the early spring of 2009 and 2010. Biochar was surface applied on a tall fescue pasture [Lolium arundinaceum (Schreb.) Darbysh. (=Festuca arundinacea Schreb. subsp. arundinacea)] and tilled in on two green pepper field sites. The soils were analyzed for carbon (C) content, pH, CEC, Mehlich 1 P, and SS. No significant difference was found in yields at any of the three sites, but differences in forage quality were found. Biochar made from poultry litter showed several benefits as a soil amendment in all the studies, but application rates would be limited by soil test P and pH.