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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Water Management Research » Research » Publications at this Location » Publication #335765

Research Project: Developing Sustainable Cropping Systems to Improve Water Productivity and Protect Water and Soil Quality in Irrigated Agriculture

Location: Water Management Research

Title: Nitrous oxide emissions affected by biochar and nitrogen stabilizers

Author
item Cai, Zejiang - Beijing Academy Of Agricultural Sciences
item Gao, Suduan
item Xu, Minggang - Beijing Academy Of Agricultural Sciences

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/28/2016
Publication Date: 12/11/2016
Citation: Cai, Z., Gao, S., Xu, M. 2016. Nitrous oxide emissions affected by biochar and nitrogen stabilizers. American Geophysical Union (AGU), December 12-16, 2016, San Francisco, California. Paper No. B13B-0570.

Interpretive Summary:

Technical Abstract: Both biochar and N fertilizer stabilizers (N transformation inhibitors) are potential strategies to reduce nitrous oxide (N2O) emissions from fertilization, but the mechanisms and/or N transformation processes affecting the N dynamics are not fully understood. This research investigated N2O emissions and N transformations in soil amended with biochar and N transformation inhibitors. The soil was a sandy loam soil and adjusted to 10% soil water content and incubated at 25 degrees C. Biochar amendment at 1% (w/w), Agrotain® Ultra (urease inhibitor), Agrotain® Plus (urease and nitrification inhibitor), and N-Serve® 24 (nitrification inhibitor) as well as another potential nitrification inhibitor, potassium thiosulfate (KTS), at 0.25-1:1 K2O/N ratios (w/w) were tested. Emissions of N2O, soil mineral N species change, and soil pH were determined for 35 days after fertilizers were applied. Biochar, Agrotain® Ultra or Plus, or N-Serve® 24 all effectively reduced N2O emissions by more than 60% as compared to no amendment control. The KTS, however, was only effective in reducing N2O emissions at a high ratio (1:1 K2O/N, w/w). There was a strong correlation between N2O emission and the concentration of nitrite (NO2-) in soil but no other mineral species. All the amendments showed that their effects on N transformation and N2O emissions were completed within a few weeks after application. Laboratory analysis indicated that biochar affected the N dynamics most likely via adsorption of ammonium (NH4+) and the inhibitors by affecting N transformation rate. This research has gained further understanding on how biochar and N stabilizers affect N2O emissions and the knowledge can assist in developing mitigation strategies.