Soil N2O and CH4 emissions from fodder maize production with and without riparian buffer strips of differing vegetation

Abstract

Purpose Nitrous oxide (N2O) and methane (CH4) are some of the most important greenhouse gases in the atmosphere of the 21st century. Vegetated riparian buffers are primarily implemented for their water quality functions in agroecosystems. Their location in agricultural landscapes allows them to intercept and process pollutants from adjacent agricultural land. They recycle organic matter, which increases soil carbon (C), intercept nitrogen (N)-rich runoff from adjacent croplands, and are seasonally anoxic. Thus processes producing environmentally harmful gases including N2O and CH4 are promoted. Against this context, the study quantified atmospheric losses between a cropland and vegetated riparian buffers that serve it. Methods Environmental variables and simultaneous N2O and CH4 emissions were measured for a 6-month period in a replicated plot-scale facility comprising maize (Zea mays L.). A static chamber was used to measure gas emissions. The cropping was served by three vegetated riparian buffers, namely: (i) grass riparian buffer; (ii) willow riparian buffer and; (iii) woodland riparian buffer, which were compared with a no-buffer control. Results The no-buffer control generated the largest cumulative N2O emissions of 18.9 kg ha− 1 (95% confidence interval: 0.5–63.6) whilst the maize crop upslope generated the largest cumulative CH4 emissions (5.1 ± 0.88 kg ha− 1). Soil N2O and CH4-based global warming potential (GWP) were lower in the willow (1223.5 ± 362.0 and 134.7 ± 74.0 kg CO2-eq. ha− 1 year− 1, respectively) and woodland (1771.3 ± 800.5 and 3.4 ± 35.9 kg CO2-eq. ha− 1 year− 1, respectively) riparian buffers. Conclusions Our results suggest that in maize production and where no riparian buffer vegetation is introduced for water quality purposes (no buffer control), atmospheric CH4 and N2O concerns may result.

Do NO, N2O, N2 and CO2 fluxes differ in soils sourced from cropland and varying riparian buffer vegetation? An incubation study

“…The emissions of N 2 O and CO 2 have been studied within different riparian buffer vegetations (Baskerville et al, 2021 ; Silverthorn & Richardson, 2021 ), but a direct comparison of these with gases emitted by the agricultural fields they serve remains elusive (Davis et al, 2019 ). In field studies, Davis et al ( 2019 ), Dlamini, Cardenas, Tesfamariam, Dunn, et al ( 2022 ), and Iqbal et al ( 2015 ) found greater N 2 O fluxes from a cropland compared with adjacent riparian buffers as a result of nitrogen fertilization while the riparian buffers were not directly fertilized. In contra, Kim et al ( 2009 ) and Mafa‐Attoye et al ( 2020 ) reported larger N 2 O fluxes from riparian buffers as a result of their greater soil moisture retention compared with the adjacent croplands.…”

Effects of different fertilization practices on CH4 and N2O emissions in various crop cultivation systems: A case study in Kazakhstan

“…Among these gases, CH4 is of particular concern, being the second most important contributor to radiative forcing after CO2 (Cassia et al, 2018). It possesses a significantly higher global warming potential, with a 100-year warming potential approximately 28 times that of CO2 (Dlamini et al, 2022). Agricultural practices, especially in rice paddies, have been identified as substantial sources of CH4 and N2O emissions.…”