Nitrous oxide emissions and nitrate leaching from a rain-fed wheat-maize rotation in the Sichuan Basin, China
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Minghua Zhou, Bo Zhu, Butterbach-Bahl, K., Xunhua Zheng, Tao Wang and Yanqiang Wang. 2013. Nitrous oxide emissions and nitrate leaching from a rain-fed wheat-maize rotation in the Sichuan Basin, China. Plant and Soil 362(1-2): 149 - 159
Permanent link to cite or share this item: http://hdl.handle.net/10568/34463
Aims A 3-year field experiment (October 2004–October 2007) was conducted to quantify N2O fluxes and determine the regulating factors from rain-fed, N fertilized wheat-maize rotation in the Sichuan Basin, China. Methods Static chamber-GC techniques were used to measure soil N2O fluxes in three treatments (three replicates per treatment): CK (no fertilizer); N150 (300 kg N fertilizer ha−1 yr−1 or 150 kg Nha−1 per crop); N250 (500 kg N fertilizer ha−1 yr−1 kg or 250 kg Nha−1 per crop). Nitrate (NO3−) leaching losses were measured at nearby sites using free-drained lysimeters. Results The annual N2O fluxes from the N fertilized treatments were in the range of 1.9 to 6.7 kg Nha−1 yr−1corresponding to an N2O emission factor ranging from 0.12%to 1.06%(mean value: 0.61%). The relationship between monthly soil N2O fluxes and NO3- leaching losses can be described by a significant exponential decaying function. Conclusions The N2O emission factor obtained in our study was somewhat lower than the current IPCC default emission factor (1 %). Nitrate leaching, through removal of topsoil NO3−, is an underrated regulating factor of soil N2O fluxes from cropland, especially in the regions where high NO3- leaching losses occur.