Dryland Soil Greenhouse Gases and Yield‐Scaled Emissions in No‐Till and Organic Winter Wheat–Fallow Systems

• DOI: 10.2136/sssaj2015.08.0295
• Publication Date: 2016-02-25T16:57:16Z
• Authors: Tunsisa T. Hurisso; Urszula Norton; Jay B. Norton; Judith Odhiambo; Stephen J. Del Gr...; Gary W. Hergert; Drew J. Lyon
• Keywords: Summer fallow; Panicum miliaceum; Soil carbon; Cropping system

Core Ideas Dryland organic and no‐till wheat‐fallow systems impact GHG wheat yields. The system produced more grain yield than the in a dry year. had greater emissions during fallow period. Concerted effort toward reducing tillage is needed to reduce overall emission dryland wheat–fallow systems. In semiarid central Great Plains of United States, cropping intensification beyond traditional winter ( Triticum aestivum L.)–fallow rotation along with reduced can lead soil matter (SOM) conservation offset greenhouse gas emission. Here, we quantified (i) (GHG) carbon dioxide (CO 2 ), methane (CH 4 nitrous oxide (N O) fluxes, (ii) yield‐scaled from (NT) production western Nebraska over 2‐yr evaluated were wheat–proso millet Panicum miliaceum (NT 3 yr), wheat–millet–fallow–winter wheat–sunflower Helianthus annuus 6 wheat–millet or sunflower–fallow (Organic yr). 2012 2013, CO N O fluxes phase generally higher relative Organic 3‐yr system. phase, however, these NT 6‐yr system, suggesting mineralization under former. CH tended be Compared lower (0.026 vs. 0.014 Mg [CH + O] equivalent −1 yield). More tillage‐caused disturbance intensity further SOM depletion