Wednesday, November 7, 2007 - 11:35 AM
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Effect of Two Types of Pyrolysis Chars on Corn Yield, Soil Nutrient Status, and Soil C in Loamy Sand Soil of the Southeastern United States.

Julia Gaskin1, R. Adam Speir2, Keith R. Harris1, R. Dewey Lee3, Lawrence Morris4, and K.C. Das1. (1) Biological & Agricultural Engineering, University of Georgia, Driftmier Engineering Center, Athens, GA 30602, (2) Warnell School of Forestry and Natural Resources, University of Georgia, University of Georgia, Athens, GA 30602, (3) PO Box 748, University of Georgia, University of Georgia, 4604 Research Way, Tifton, GA 31793, (4) University of Georgia, University of Georgia, Department of Soils, Warnell School of Forest Resources, Athens, GA 30602

We have investigated whether additions of a pyrolysis char to Tifton loamy sand (fine loamy, koalinitic, thermic, plinthic Kandiudults) in the southeastern United States would benefit corn (Zea mays) yield, improve soil nutrient status, and contribute to stable soil carbon over two growing seasons. We measured corn growth response, available soil nutrients (Mehlich I), and soil C in microplots (1.8 x 2.2 m) amended with peanut hull and pine chip pellet char produced at 400o C with steam. For each char, the treatments were char at 11.2 Mg ha-1, 11.2 Mg ha-1 with fertilizer, 22.4 Mg ha-1, 22.4 Mg ha-1 plus fertilizer, a control, and a fertilizer check (4 replicates). Soil samples were taken before plot amendment, at harvest (Yr 1), before planting (Yr 2), and again at harvest (Yr 2). Analyses of the char indicated that a significant amount of nutrients could be added with the peanut hull char at the 11.2 Mg ha-1 rate (213 kg N ha-1, 1.3 kg P ha-1, and 56 kg K ha-1) and soil samples at Yr 1 harvest reflected an increase in available K in char amended plots compared to the control and fertilizer check. Nutrient additions with the pine chip char were low and no differences in available nutrients were seen. During Yr 1, total biomass and yield were not significantly higher with the char plus fertilizer additions than the fertilizer. There was no significant yield or biomass response to the addition of pine chip char alone. There was a significant response of stover, but not grain yield to peanut hull char alone in Yr 1.