ARS | Publication request: Cropping Sequence and Nitrogen Fertilization Effects on Dryland Soil Nitrous Oxide Emission

Submitted to: Proceedings of Great Plains Soil Fertility Conference
Publication Type: Proceedings
Publication Acceptance Date: January 6, 2010
Publication Date: March 2, 2010
Citation: Sainju, U.M. 2010. Cropping Sequence and Nitrogen Fertilization Effects on Dryland Soil Nitrous Oxide Emission. Proceedings of Great Plains Soil Fertility Conference. p. 24-29.

Technical Abstract: Emission of nitrous oxide (N2O), a potent greenhouse gas responsible for global warming, may be influenced by cropping and N fertilization management. The effects of three cropping sequences [no-tilled continuous malt barley (NTCB), no-tilled malt barley-pea (NTB-P), and conventional tilled malt barley-fallow (CTB-F)] and two N fertilization rates (0 and 80 kg N ha-1) were evaluated on soil surface N2O emission in 2008 and 2009 in eastern Montana. The CTB-F is the conventional farming system and 80 kg N ha-1 is the recommended rate of N fertilization to dryland malt barley in the region. Emission of N2O peaked following N fertilization and substantial precipitation when emission tended to be greater in NTCB and NTB-P than in CTB-F and greater with N fertilization than without. Total emission from April to November was greater in NTCB and NTB-P than in CTB-F and with 80 than with 0 kg N ha-1 in 2008 but was not different among cropping sequences and N rates in 2009. Emission was also greater with cropping than with fallow phase. Increased N substrate availability due to N fertilization to crops and N mineralization from pea residue and soil water availability due to precipitation probably increased microbial activity and N2O emission.