Environmental Science: Water Science and Technology
; Earth and Planetary Sciences: Earth-Surface Processes
; Environmental Science: Environmental Chemistry
英文摘要:
Straw incorporation is a common agricultural practice, but the additional carbon source may increase greenhouse gas emissions by stimulating microbial activity in soil, particularly when straw is applied at the same time as nitrogen (N) fertilizer. We investigated the coupled effects of straw and N fertilizer on greenhouse gas emissions in a rainfed winter wheat–summer fallow system in Northwest China. Simultaneous applications of straw and N fertilizer increased N2O emissions by up to 88%, net greenhouse gas (NGHG) emission and net greenhouse gas intensity (NGHGI) by over 90%, and the N2O emission factor by over 2-fold. When straw was applied before N fertilizer, the emission factor (0.22%) decreased by approximately one-half compared with that for simultaneous applications (0.45%). In addition, early straw incorporation decreased N2O emissions, NGHG, and NGHGI by 35% (0.62�kg N2O-N�ha−1�yr−1), 40% (242�kg CO2-eq�ha−1�yr−1), and 38% (42�kg CO2-eq�t−1 grain), respectively. We identified the period 30–35 days after N fertilization as a crucial period for evaluating the effectiveness of management practices on N2O emissions. The time between straw and fertilizer applications was negatively related to N2O emission (R2�=�0.8031; p�<�0.01) but positively related to soil CH4 uptake (R2�=�0.7662; p�<�0.01). Therefore, early straw incorporation can effectively mitigate greenhouse gas emissions by reducing N2O flux and increasing soil CH4 uptake without significantly decreasing grain yield. � 2017
College of Natural Resources and Environment, Northwest A & F University, Yangling, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of AgricultureShaanxi, China; College of Resources and Environmental Sciences, China Agricultural University, Beijing, China
Recommended Citation:
Htun Y,M,, Tong Y,et al. Coupled effects of straw and nitrogen management on N2O and CH4 emissions of rainfed agriculture in Northwest China[J]. Atmospheric Environment,2017-01-01,157