The Effect of Different Biochars On Selected Soil Chemical Properties.

Biochar is a co-product of pyrolysis of plant material.  It is believed that its qualities vary according to feedstock used and reactor conditions during pyrolysis.   An incubation study was conducted to try to determine the effect of biochar application on selected soil properties related to plant growth.  Fifty grams of Nicollet soil (fine-loamy, mixed, superactive, mesic Aquic Hapludoll) was mixed with of one of seventeen different biochars from six different feed stocks and six different charring methods at a rate equivalent to 36 Mg ha^-1.  A nitrogen solution (urea dissolved in DDI water) was added to the soil + biochar at a rate equivalent to 224 kg N ha^-1.Treatments were a soil only, soil + urea, soil + different biochars and soil + urea + different biochars.  Treatments of soil + urea + different biochars were replicated four times for each sampling time.  Treatments were sampled immediately following treatment application and after 1, 2, 4, 6 and 8 weeks using destructive sampling techniques.  The samples were analyzed for total nitrogen, total carbon, organic matter, ammonium-N and nitrate-N.  The results indicate that the different feedstocks and charring processes significantly influenced the biochars’ reaction in the soil.