Effects of Hardwood Biochar on Soil Acidity, Nutrient Dynamics, and Sweet Corn Productivity

ABSTRACT

Interest is rising in amending agricultural soils with carbon-rich materials such as charcoal to improve soil fertility. The objectives of this field study were to evaluate sugar maple hardwood charcoal (biochar) as a soil amendment. The design of the experiment was split-plot with five replications, repeated over two growing seasons with sweet corn (Zea mays L.) production. Main plots were allocated to five application amounts of biochar including 0%, 2%, 4%, 6%, and 8% by weight (0, 40, 80, 120, and 160 Mg ha⁻¹, respectively). Sub-plots consisted of applications of 0 or 56 kg nitrogen ha⁻¹ as calcium ammonium nitrate. Soil pH increased from pH 5.8 to 6.7 with biochar additions. The percent base saturation was increased due to the retention of calcium, magnesium, and potassium. Soil phosphate availability increased. Sweet corn yield in the biochar-amended plots was depressed except with the 2% application. The result of the study revealed that no more than 2% application of sugar maple hardwood biochar should be applied for sweet corn growth.

KEYWORDS:

• Hardwood charcoal
• soil nutrients
• nitrate
• zea mays

Acknowledgments

This material is based upon work supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, UMass Extension, the Massachusetts Agricultural Experiment Station and the Stockbridge School of Agriculture at the University of Massachusetts Amherst, under project number MAS00538 as well as by a grant from Sustainable Agriculture Research and Education (SARE; Grant # GNE14-075). The authors thank Dr. Wesley Autio for his guidance in statistical analysis. The authors also appreciate Dr. Sarah Weis for her support in the laboratory measurements.

Additional information

Funding

This work was supported by the Sustainable Agriculture Research and Education, United States Department of Agriculture [Grant # GNE14-075].