Biochar and Fertilizer Effects on Wheat Growth and Soil Properties.

Biochar can be used as a soil amendment for improving soil health and crop productivity. A greenhouse experiment was carried out at the Columbia Basin Agricultural Research Center, near Pendleton, OR, to study the effects of different application rates of biochar and chemical fertilizer addition on wheat growth and soil properties. The experiment had four rates of biochar (0, 12.5, 25 and 50 Mg ha ^-1) and two rates of chemical fertilizer application (no fertilizer, and 90 kg N ha^-1, 45 kg P ha^-1 and 20 kg S ha^-1). The soil used in the study was Walla Walla Silt Loam (coarse-silty, mixed, superactive, mesic Typic Haploxerolls) with a long history of dryland winter wheat (Triticum aestivum L.) - summer fallow cropping. Biochar at the rate of 12.5 and 25 Mg ha^-1 with and without fertilizer increased shoot and root biomass of wheat. Biochar significantly increased soil pH, soil organic matter (SOM), phosphorous, potassium, and sulfur contents. The increase in pH and nutrient content were observed with increasing rate of biochar up to 50 Mg ha^-1. Biochar up to 25 Mg ha^-1 increased SOM compared to nil biochar treatment when no fertilizer was applied whereas, with fertilizer application SOM increased with all rates of biochar. Similarly; at the highest rate (50 Mg ha^-1) the positive effect of biochar on shoot biomass was not evident particularly without fertilizer indicating a possible nutrient tie-up at the high rate of biochar. Biochar-based soil management can enhance biomass production along with positive effects on soil quality. Field experiments can further quantify long-term agronomic and environmental benefits of biochar.