Influence of Biochar on Nitrogen Fractions in a Coastal Plain Soil
- Harry H. Schomberg *a,
- Julia W. Gaskinb,
- Keith Harrisb,
- K.C. Dasb,
- Jeff M. Novakc,
- Warren J. Busscherc,
- Don W. Wattsc,
- Robin H. Woodroofa,
- Isabel M. Limad,
- Mohamed Ahmednae,
- Djaafar Rehrahe and
- Baoshan Xingf
- a USDA–ARS, J. Phil. Campbell, Sr. Natural Resource Conservation Center, Watkinsville, GA, 30677
b Biological and Agricultural Engineering Dep., Univ. of Georgia, Athens, GA, 30602
c USDA–ARS, Coastal Plains Research Laboratory, Florence, SC, 29501
d USDA–ARS, Southern Regional Research Center, New Orleans, LA, 70124
e Interdisciplinary Energy and Environmental Program, North Carolina Agricultural & Technological State Univ., Greensboro, NC, 27411
f Plant, Soil and Insect Sciences Dep., Univ. of Massachusetts, Amherst, MA, 01003. The use of trade, firm, or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the United States Department of Agriculture or the Agricultural Research Service of any product or service to the exclusion of others that may be suitable. Assigned to Associate Editor David Laird.
Interest in the use of biochar from pyrolysis of biomass to sequester C and improve soil productivity has increased; however, variability in physical and chemical characteristics raises concerns about effects on soil processes. Of particular concern is the effect of biochar on soil N dynamics. The effect of biochar on N dynamics was evaluated in a Norfolk loamy sand with and without NH4NO3. High-temperature (HT) (≥500°C) and low-temperature (LT) (≤400°C) biochars from peanut hull (Arachis hypogaea L.), pecan shell (Carya illinoinensis Wangenh. K. Koch), poultry litter (Gallus gallus domesticus), and switchgrass (Panicum virgatum L.) and a fast pyrolysis hardwood biochar (450–600°C) were evaluated. Changes in inorganic, mineralizable, resistant, and recalcitrant N fractions were determined after a 127-d incubation that included four leaching events. After 127 d, little evidence of increased inorganic N retention was found for any biochar treatments. The mineralizable N fraction did not increase, indicating that biochar addition did not stimulate microbial biomass. Decreases in the resistant N fraction were associated with the high pH and high ash biochars. Unidentified losses of N were observed with HT pecan shell, HT peanut hull, and HT and LT poultry litter biochars that had high pH and ash contents. Volatilization of N as NH3 in the presence of these biochars was confirmed in a separate short-term laboratory experiment. The observed responses to different biochars illustrate the need to characterize biochar quality and match it to soil type and land use.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2012. . Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.