Soil Amendments Alter Ammonia-Oxidizing Archaea and Bacteria Communities in Rain-Fed Maize Field in Semi-Arid Loess Plateau

Abstract

Ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) are key drivers of nitrification in rainfed soil ecosystems. However, within a semi-arid region, the influence of different soil amendments on the composition of soil AOA and AOB communities and soil properties of rainfed maize is still unclear. Therefore, in this study, the abundance, diversity, and composition of AOA and AOB communities and the potential nitrification activity (PNA) was investigated across five soil treatments: no fertilization (NA), urea fertilizer (CF), cow manure (SM), corn stalk (MS), and cow manure + urea fertilizer (SC). The AOB amoA gene copy number was influenced significantly by fertilization treatments. The AOB community was dominated by Nitrosospira cluster 3b under the CF and SC treatments, and the AOA community was dominated by Nitrososphaera Group I.1b under the CF and NA amendments; however, manure treatments (SM, MS, and SC) did not exhibit such influence. Network analysis revealed the positive impact of some hub taxonomy on the abundance of ammonia oxidizers. Soil pH, NO3−-N, Module 3, biomass, and AOB abundance were the major variables that influenced the potential nitrification activity (PNA) within structural equation modeling. PNA increased by 142.98–226.5% under the treatments CF, SC, SM, and MS compared to NA. In contrast to AOA, AOB contributed dominantly to PNA. Our study highlights the crucial role of bacterial communities in promoting sustainable agricultural production in calcareous soils in semi-arid loess plateau environments.

Nitrogen fertilization promoted microbial growth and N2O emissions by increasing the abundance of nirS and nosZ denitrifiers in semiarid maize field

“…The application of the N1 treatment had a relatively minor impact on soil N 2 O emissions compared to N3 and N2 fertilizer treatments. However, the decomposition of nitrogen fertilizer via hydrolysis led to the release of heavily oxidized nitrate substrates (NO 3 − -N), which subsequently caused a rise in N 2 O emissions ( Ouyang et al, 2018 ; Fudjoe et al, 2021 ).…”

“…Maize crop is extensively grown in various regions worldwide, including semiarid areas like the Loess Plateau, which holds significant agricultural importance. The semi-arid Loess Plateau (SALP) in northwestern China is recognized as one of the most fragile agroecosystems globally, heavily reliant on limited and unpredictable rainfall ( Qiu et al, 2014 ; Zhang et al, 2018 ; Fudjoe et al, 2021 ). To address this challenge, farmers frequently adopt the use of plastic mulch to in reduce water evaporation and retain moisture, fulfilling the crop’s essential growth requirements and resulting in enhanced crop yields and improved water use efficiency in the bulk and rhizosphere soil ( Bu et al, 2014 ; Lamptey et al, 2019 ; Zhang et al, 2021 ).…”

The impact of fertilization on ammonia-oxidizing bacteria and comammox Nitrospira communities and the subsequent effect on N2O emission and maize yield in a semi-arid region

“…Excessive fertilization has raised numerous environmental and ecological concerns, including soil acidification, increased nitrous oxide (N 2 O) gas emissions, and water pollution (Hink et al, 2018;Fudjoe et al, 2021). N 2 O is a potent greenhouse gas with a global warming potential of ∼300× that of carbon dioxide, which also poses a significant threat to the stratospheric ozone layer and overall climate stability (Schmidt et al, 2019;Chataut et al, 2023).…”

“…The increase in fertilizer usage enhances N 2 O emissions within the maize field (Bu et al, 2014;Zhang F. et al, 2018;Govindasamy et al, 2023). The use of plastic mulch can reduce water evaporation and retain moisture to meet the needs of crops in their crucial growth stages, thereby increasing crop yield and water use efficiency (Lamptey et al, 2019;Fudjoe et al, 2021).…”

“…Co-occurrence networks can help reveal their taxa's ecological and microbe-to-microbe associations. Additionally, these networks are capable of handling large datasets (Zhang B. et al, 2018;Fudjoe et al, 2021). However, it is essential to identify keystone taxa that maintain function and structure within soil microbial communities (Williams et al, 2014;Mamet et al, 2019).…”