Biochar Effect on Soil Physical and Chemical Properties and Bermudagrass Growth

As population continues to rise and development continues, there is increasing pressure for the production of food on a decreasing amount of land as well as an increased need for combustible fuel. Biofuels produced from agricultural products may be able to alleviate some of the demands on foreign oil, and the byproduct, biochar, is reported to have positive effects on soil properties and crop growth when applied to soils. To test this, biochar produced from sorghum (sorghum bicolor) was field tested on sandy loam soil at rates of 0, 4, 8, 12, and 16 Mg ha^-1. Biochar was applied to soil using two different methods, surface applied and incorporated down to 15 cm, and bermudagrass (cynodon dactylon) was grown from seed. Runoff, sediment loss, biomass yield, saturated hydraulic conductivity, water holding capacity, bulk density, porosity, and soil nutrients were tested in a randomized block design. Biochar did not have a significant effect on physical parameters, biomass, or runoff and sediment loss (α=0.05). Biochar application to soils produced a significant linear increase on certain soil chemical parameters six months after application (pH and K). Soil test K continued to show a linear increase 22 months after biochar application; however the linear trend was reversed for pH with incorporated biochar. Additionally, a greenhouse study was conducted using the same biochar source with identical application rates and application methods. Three soils were tested, an acidic fine sandy loam (Rader fine sandy loam), an acidic clay (Burleson clay), and an alkaline clay (Ships). Soil temperature, water loss, emergence rates, biomass yields, nutrient mass export, and bulk density were tested. Surface applied biochar enchanced bermudagrass emergence, increasing the germination index (α=0.05) for Burleson clay and Ships clay soils. Biochar application increased biomass yields for 8 and 12 Mg ha^-1 rates for Burleson soils compared to other application rates. Moreover, rates above 12 Mg ha^-1 decreased biomass yield, indicating a quadratic response to biochar application. There was not a significant difference in nutrient uptake in bermudagrass tissue, nor was there a significant change in soil bulk density in response to biochar application