Implication of O2 dynamics for both N2O and CH4 emissions from soil during biological soil disinfestation

Abstract

Soil O2 dynamics have significant influences on greenhouse gas emissions during soil management practice. In this study, we deployed O2-specific planar optodes to visualize spatiotemporal distribution of O2 in soils treated with biological soil disinfestation (BSD). This study aimed to reveal the role of anoxia development on emissions of N2O and CH4 from soil amended with crop residues during BSD period. The incorporation of crop residues includes wheat straw only, wheat straw with biochar and early straw incorporation. The anoxia in soil developed very fast within 3 days, while the O2 in headspace decreased much slower and it became anaerobic after 5 days, which was significantly affected by straw and biochar additions. The N2O emissions were positively correlated with soil hypoxic fraction. The CH4 emissions were not significant until the anoxia dominated in both soil and headspace. The co-application of biochar with straw delayed the anoxia development and extended the hypoxic area in soil, resulting in lower emissions of N2O and CH4. Those results highlight that the soil O2 dynamic was the key variable triggering the N2O and CH4 productions. Therefore, detailed information of soil O2 availability could be highly beneficial for optimizing the strategies of organic amendments incorporation in the BSD technique.

Increasing the Environmental Sustainability of Greenhouse Vegetable Production by Combining Biochar Application and Drip Fertigation—Effects on Soil N2O Emissions and Carbon Sequestrations

“…Biochar is a more recalcitrant organic material with higher organic carbon content than maize straw [33][34][35][36] and it has been found to have the potential to reduce greenhouse gas emissions when used as a soil amendment in agroecosystems [37][38][39]. Furthermore, biochar incorporation improves soil physical properties, such as the water-holding capacity [40] and aeration of soils [41,42], and provides an additional absorption capacity for mineral nutrients [33,43,44], which would be beneficial for plant growth under the drip fertigation practice. However, whether the application of biochar to greenhouse soils could significantly reduce soil N 2 O emission fails to reach an agreement [45][46][47], as they depend on soil temperature and residual mineral N content [37,38,48].…”

Cover crop residue decomposition triggered soil oxygen depletion and promoted nitrous oxide emissions

“…1 a, 2 a, 4 a). As previously reported in other studies 46 , 47 , the use of optode technology enables the visualization of highly-resolved spatial soil O 2 dynamics following exogenous C incorporation. In the present study, the O 2 images clearly demonstrated that within 24 h following N fertilization, the top 3 cm of soil experienced significant O 2 depletion in treatments with cover crops and 50% WFPS (Figs.…”

“…Based on O 2 content, soils O 2 can be categorized into three groups as in Wang et al 46 : oxic (> 2.00 mg L −1 , equivalent air saturation > 22.5%), hypoxic (0.14 to 2.00 mg L −1 , equivalent air saturation 1.6 to 22.5%) and anoxic (< 0.14 mg L −1 , equivalent air saturation < 1.6%) conditions.…”

Editors’ Choice—Luminescent Oxygen Sensors: Valuable Tools for Spatiotemporal Exploration of Metabolism in In Vitro Systems

“…Microbiologists and environmental scientists have taken advantage of the planar optode to measure the formation of gradients and heterogeneities caused by the consumption or production of O 2 in soil. [29][30][31][32] In recent applications, the integration of an O 2 optode on to the walls of an in vitro soil column has allowed for researchers to characterize rhizospheres (Fig. 2B), 24,33 implicate disinfestation in microbial mediated greenhouse gas emission, 31 and link millimeterscale O 2 heterogeneity to post-fire biogeochemical responses.…”

“…[29][30][31][32] In recent applications, the integration of an O 2 optode on to the walls of an in vitro soil column has allowed for researchers to characterize rhizospheres (Fig. 2B), 24,33 implicate disinfestation in microbial mediated greenhouse gas emission, 31 and link millimeterscale O 2 heterogeneity to post-fire biogeochemical responses. 30 Not only can the optode identify hotspots (represented by O 2 heterogeneities in 2D), but the reversibility of the molecular probe inside the host matrix can allow for identification of hot moments in soil over longer time scales towards the goal of monitoring long term nutrient dynamics.…”