Methane uptake in semiarid farmland subjected to different mulching and nitrogen fertilization regimes

Inorganic nitrogen fertilizer and high N application rate promote N2O emission and suppress CH4 uptake in a rotational vegetable system

“…As a result, weaker CH 4 oxidization in inorganic fertilizer treatments likely led to a lower CH 4 uptake, relative to organic fertilizer treatments. For CH 4 consumption, previous studies have generally recognized that CH 4 was oxidized under aerobic soil environment and the CH 4 uptake rate was found to decrease with greater soil moisture and increase with increasing soil temperature (Liu et al, 2016;Meng et al, 2020). However, CH 4 uptake fluxes showed very little response to the changes in WFPS during each growing season in this study, while soil temperature was negatively associated with CH 4 uptake for the two fertilizer treatments.…”

“…1, b-c). Many studies suggested that soil CH 4 uptake was positively correlated with soil temperature, but negatively correlated with soil moisture (Liu et al, 2016;Meng et al, 2020). Besides, low mineral-N content during the season (no basal dressing) might be another contributing factor to the unusually large CH 4 uptake fluxes.…”

“…Whereas, at WFPS of 60-70%, denitrification is the dominant N 2 O source (Case et al, 2012). Soil CH 4 uptake is also positively correlated with soil temperature, and yet negatively correlated with soil moisture for cultivated maize (Liu et al, 2016), planted woodland (Wu et al, 2018), and rain-fed potato (Wang et al, 2015). Others have suggested that soil CH 4 uptake can be suppressed at both low and high soil moisture contents, through the inhibition of methanotrophs activities or through the limitation of CH 4 and O 2 diffusion and transport (Del Grosso et al, 2000;Ran et al, 2017).…”

Response of Labile Organic Matter Fractions to Plastic Film Removal During Maize (Zea Mays L.) Growth in Semiarid Farmland Soil

“…Plastic film mulching is a worldwide agricultural technology with direct economic and environmental benefits, such as improving crop productivity, increasing water-use efficiency, improving soil quality, reducing greenhouse gas emissions, and reducing nitrate leaching (Wang et al, 2017;Liu et al, 2014bLiu et al, , 2015Liu et al, , 2016. The Loess Plateau has a typical semi-arid monsoon climate, in which maize (Zea mays L.) is one of the most common grain crops; however, low temperature and drought in the early growth stage of spring crops often lead to low crop yield (Liu et al, 2009).…”

Methanotrophs are favored under hypoxia in ammonium-fertilized soils

“…Recent studies emphasize that its environmental consequences are not fully recognized. Ammonium can competitively inhibit CH 4 oxidation (Alam and Jia 2012;Bender and Conrad 1995;Dunfield and Knowles 1995;Saari et al 2004;Steinkamp et al 2001;Wang and Ineson 2003;Xu and Inubushi 2004;Zheng et al 2013), but also can stimulate the oxidation (Bodelier et al 2000;Hu and Lu 2015;Krüger and Frenzel 2003;Rigler and Zechmeister-Boltenstern 1999) or have no effect (Bender and Conrad 1995;Liu et al 2016). Mineral N turnover is strongly affected by O 2 availability (e.g., nitrification in aerobic conditions, denitrification in anaerobic conditions) (Stępniewski and Stępniewska 2009) and affects the concentrations of soluble N forms (NH 4…”