Evaluating Nitrogen Management Practices for Greenhouse Gas Emission Reduction in a Maize Farmland in the North China Plain: Adapting to Climate Change

Huayun He; Qi Hu; Feifei Pan; Xuebiao Pan

doi:10.3390/plants12213749

Evaluating Nitrogen Management Practices for Greenhouse Gas Emission Reduction in a Maize Farmland in the North China Plain: Adapting to Climate Change

Plants (Basel). 2023 Nov 2;12(21):3749. doi: 10.3390/plants12213749.

Authors

Huayun He^{1

2}, Qi Hu^{1

2}, Feifei Pan³, Xuebiao Pan^{1

2}

Affiliations

¹ College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
² China Meteorological Administration-China Agricultural University (CMA-CAU) Jointly Laboratory of Agriculture Addressing Climate Change, Beijing 100193, China.
³ Department of Geography and the Environment, University of North Texas, Denton, TX 76203, USA.

Abstract

Quantification of the trade-offs among greenhouse gas (GHG) emissions, yield, and farmers' incomes is essential for proposing economic and environmental nitrogen (N) management strategies for optimizing agricultural production. A four-year (2017-2020) field experiment (including four treatments: basic N fertilizer treatment (BF), suitable utilization of fertilization (SU), emission reduction treatment (ER), and high fertilization (HF)) was conducted on maize (Zea mays L.) in the North China Plain. The Life Cycle Assessment (LCA) method was used in this study to quantify the GHG emissions and farmers' incomes during the whole maize production process. The total GHG emissions of BF, SU, ER, and HF treatments in the process of maize production are 10,755.2, 12,908.7, 11,950.1, and 14,274.5 kg CO₂-eq ha^-1, respectively, of which the direct emissions account for 84.8%, 76.8%, 74.9%, and 71.0%, respectively. Adding inhibitors significantly reduced direct GHG emissions, and the N₂O and CO₂ emissions from the maize fields in the ER treatment decreased by 30.0% and 7.9% compared to those in the SU treatment. Insignificant differences in yield were found between the SU and ER treatments, indicating that adding fertilizer inhibitors did not affect farmers' incomes while reducing GHG emissions. The yield for SU, ER, and HF treatments all significantly increased by 12.9-24.0%, 10.0-20.7%, and 2.1-17.4% compared to BF, respectively. In comparison with BF, both SU and ER significantly promoted agricultural net profit (ANP) by 16.6% and 12.2%, with mean ANP values of 3101.0 USD ha^-1 and 2980.0 USD ha^-1, respectively. Due to the high agricultural inputs, the ANP values in the HF treatment were 11.2%, 16.6%, and 12.4% lower than those in the SU treatment in 2018-2020. In conclusion, the combination of N fertilizer and inhibitors proved to be an environmentally friendly, high-profit, and low-emissions production technology while sustaining or even increasing maize yields in the North China Plain, which was conducive to achieving agricultural sustainability.

Keywords: agricultural net profit; greenhouse gas; life cycle assessment; maize yield; nitrogen management.

Grants and funding

This research was funded by the National Key Research and Development Program of China (Grant No. 2022YFD1900302-03-02 and No. 2021YFD1901104-1).