Crop yield response to increasing biochar rates

Authors: Sorensen, Ronald - Ron; Lamb, Marshall

Submitted to: Journal of Crop Improvement
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/30/2016
Publication Date: 10/24/2016
Citation: Sorensen, R.B., Lamb, M.C. 2016. Crop yield response to increasing biochar rates. Journal of Crop Improvement. doi:10.1080/15427528.2016.12317728.

Interpretive Summary: Published literature varies widely on the actual documented yield benefit with biochar application in general and specifically to rate of application. ‘Terra Preta’ soils were estimated to contain 247 tons ac-1 biochar while 0.89 to 5.4 tons ac-1 was deemed sufficient for a significant increase in productivity. Other researchers applied biochar at 0, 3.5 and 9 tons ac-1 in a soybean-corn rotation. Corn yield increased in the 9 ton ac-1 biochar plots over the control in the first year with increased yields of 28, 30, 140% over the next three years, respectively. They attributed the yield increase to increased availability of Ca and Mg from the added biochar and the effect of biochar on the Oxisol soil. Biochar produced from a hardwood feedstock showed the most consistent yield increases after application when compared to other feedstocks. Further research to improve and more consistently define the agronomic and economic benefits and the underlying causes of biochar application in production systems was recommended from many of these. The productivity and the use of biochar in cotton-corn-peanut cropping system have yet to be addressed in Southeast US. Therefore, the objective of this research was to identify crop yield response of corn, cotton, and peanut to hardwood biochar applied one time at 0, 10, 20, 40, and 60 tons ac-1. This research was conducted at the USDA/ARS Shellman Multi-crop Irrigation Research Farm (Shellman, GA) on a Greenville fine sandy loam during the 2010 through 2014 growing seasons. Biochar was applied one time at 0, 10, 20, 40, and 60 tons ac-1. Cotton was planted for two years (2010-2011), then corn for two years (2012-2013), followed by peanut for one year (2014). Best management practices were followed for each crop to have maximum yield response. However, only nitrogen was applied to the crop (cotton and corn). No other fertilizer or soil amendment was applied during this time period. There was no difference in cotton lint yield across year, biochar rate, or year by biochar interaction. There was also no difference in corn yield across year, biochar rate, or year by biochar interaction. In addition, there was no peanut yield difference across biochar rate or grade factors of total sound mature kernels or other kernels. Overall, there was not a positive or negative effect on crop yield or quality across year or biochar rate for these crops on this soil series or type of biochar.

Technical Abstract: The benefit or detriment to crop yield from biochar application varies with biochar type/rate, soil, crop, or climate. The objective of this research was to identify yield response of cotton (Gossypium hirsutum L.), corn (Zea mayes L.), and peanut (Arachis hypogaea L.) to hardwood biochar applied at 0, 10, 20, 40, and 60 tons ac-1 in southwest Georgia, USA. Biochar was applied and mixed into the soil at a 6-in depth. Cotton (2010-2011), corn (2012-2013), and peanut (2014) were planted following strip tillage and irrigated using drip irrigation. Crops were managed using best management practices. Nitrogen fertilizer (32-0-0) was applied through the drip system at 75 and 220 lbs N ac-1 per year for cotton and corn, respectively. Soil water potential sensors were installed at 10 and 20-in soil depth and irrigation events were scheduled when both sensors averaged 0.70, 0.60, and 0.45 bar for cotton, corn, and peanut, respectively. There was no difference in cotton lint yield across year (p=0.081), biochar rate (p=0.817), or year by biochar interaction (p=0.854). There was also no difference in corn yield across year (p=0.302), biochar rate (p=0.503), or year by biochar interaction (p=0.690). In addition, there was no peanut yield difference across biochar rate (p=0.595) or grade factors of total sound mature kernels (TSMK; p=0.173) or other kernels (OK; p=0.391). Overall, there was not a positive or negative effect on crop yield or quality across year or biochar rate for these crops on this soil series or type of biochar.