Effect of Biochar and N Amendments on Soil Nutrient Supply and Pearl Millet (Pennisetum americanum) Yield.

Biochar has potential to enhance plant growth by improving soil chemical (nutrient retention, nutrient availability) and physical (bulk density, water holding capacity, permeability) characteristics. In addition, biochar can improve soil biological properties contributing to increased crop productivity and simultaneously reducing fertilizer input needs – and their losses to the environment. In this research, the effects of different biochar sources and application rates on: (1) soil physical and chemical properties; (2) the potential of biochar to improve nutrient supply when mixed with animal manure; (3) crop response (millet tissue N content, chlorophyll content, grain and stover yields) were studied. Field experiments of pearl millet with biochar application were carried out in Virginia and conducted as a randomized complete block design. Each combination of two biochar sources (peanut shell and pine wood) at three rates (0, 10, 20 Mg/ha) and manure application (0, 50, and100 kg N/ha) were replicated three times. Treatments were evenly applied to the soil surface and tilled into the soil before millet was sown. By improving soil physical and chemical properties, we hypothesized that biochar amendments mixed with manure may improve soil nutrient supply and crop yield.