Does biochar improve nitrogen use efficiency in maize?

Giovani Preza Fontes, Kristin D. Greer, Cameron M. Pittelkow

Research output: Contribution to journalArticlepeer-review


Biochar is promoted as a means of improving soil fertility. Yet, few experiments have investigated its potential to improve nitrogen (N) use efficiency for high-yielding maize production in the U.S. Midwest. We tested the hypothesis that biochar application increases inorganic soil N availability during maize growth, leading to higher grain yields and N recovery efficiency while reducing the risk of N leaching following harvest. Four N fertilizer rates (0, 90, 179, and 269 kg ha−1 as urea ammonium nitrate [UAN] solution) were applied with or without biochar (10 Mg ha−1) before planting in a two-year field study. Inorganic soil N concentration was measured during the growing season (0–15 cm), and deep soil cores were obtained following harvest (0–90 cm). Results show that biochar did not affect maize yield, crop N uptake, or N recovery efficiency (by the difference method) across N rates, and there was no biochar by N rate interaction. While biochar lowered soil inorganic N concentrations on several sampling dates, this did not translate into seasonal differences in cumulative soil N availability, although grain yields in the unfertilized control were ~10% lower with biochar, suggesting net N immobilization. Biochar partially reduced the risk of N leaching following harvest by decreasing soil N concentrations at 30–60 cm, but mean concentrations for 0–90 cm were not different. Compared to previous work highlighting the benefits of biochar in arid climates with low soil fertility, we found no evidence of increased crop yield, NRE, or reduced risk of N leaching on Mollisols in a temperate climate.

Original languageEnglish (US)
Article numbere13122
JournalGCB Bioenergy
Issue number1
StatePublished - Jan 2024


  • biochar
  • maize yield
  • nitrate leaching
  • nitrogen fertilizer
  • nitrogen use efficiency
  • soil inorganic nitrogen

ASJC Scopus subject areas

  • Forestry
  • Renewable Energy, Sustainability and the Environment
  • Agronomy and Crop Science
  • Waste Management and Disposal


Dive into the research topics of 'Does biochar improve nitrogen use efficiency in maize?'. Together they form a unique fingerprint.

Cite this