Short-Term Effects of Biochar Amendment on Greenhouse Gas Emissions from Rainfed Agricultural Soils of the Semi–Arid Loess Plateau Region

Abstract

Abstract:In rainfed agricultural ecosystems in northwest China, improving soil fertility and reducing greenhouse gas (GHG) emissions are key factors for developing sustainable agriculture. This study determined the short-term effects of different biochar amendment rates on diurnal and seasonal variations of GHG emissions in the Loess Plateau to produce a background dataset that may be used to inform nutrient management guidelines for semiarid environments. Biochar produced by pyrolysis at 300-500 • C from maize straw was applied at rates of 0, 10, 20, 30, 40, and 50 t ha −1 (T0, T1, T2, T3, T4, T5), respectively. The results indicated that in the first year after the application, T3, T4, and T5 treatments increased soil organic carbon (0-10 cm) by 54.7%, 56.3%, and 56.9% compared to the other treatments. In the first, year, biochar amendment decreased diurnal CH 4 and N 2 O flux by an average of 17-119% compared to T0, among which T3 had the lowest mean value. T3 and T4 also had similar mean CO 2 flux, which was 33% lower than T0. Application of 30 t ha −1 biochar produced the lowest cumulative CO 2 and N 2 O emissions of 2300 and 4.07 kg h −1 , respectively. Biochar amendment showed no effect on grain yiel but reduced the global warming potential and GHG emission intensity by an average of 23% and 25%, respectively. The biochar application rate of 30 t ha −1 under the conditions of this study may be an appropriate rate for improving soil C sequestration and mitigation of GHG emissions in the first year after its application to soils on semi-arid Loess Plateau.

Combined application of biochar with nitrogen fertilizer improves soil quality and reduces soil respiration whilst sustaining wheat grain yield in a semiarid environment

“…In the current study, increased yield may be attributed to increased nutrient availability as reported in earlier work [34]. Biochar amendments have previously been shown to increase crop productivity by improving soil quality [35]. This study evidenced a positive effect of biochar combined with N fertilizer amendment on soil quality and spring wheat yield consistent over three years.…”

Effects of maize straw‐derived biochar application on soil temperature, water conditions and growth of winter wheat

“…In recent years, mechanically harvested maize straw has caused some problems when irregular pieces become mixed with soils; loose soil conditions are considered unfavourable for root fixation because seedling survival is less in a moist soil environment and seedlings are susceptible to disease in winter in north China (Liu, Xu, Li, & Wang, ; Yeboah, Lamptey, Cai, & Song, ). The application of biochar derived from maize straw on to wheat fields is a novel approach for the use of low‐cost straw resources and has also been a focus of researchers seeking to improve the yields of winter wheat (Liu et al, ; Mandal et al, ).…”

Nitrous oxide, methane emissions and grain yield in rainfed wheat grown under nitrogen enriched biochar and straw in a semiarid environment

“…The soil type in the study area is sandy-loam with low fertility. The soil has a pH of ≈8.3, soil organic carbon (SOC) ≤8.13 g kg −1 , and Olsen-P ≤13 mg kg −1 as described in Yeboah et al (2018) . The type of soil in the study area is the principal soil for cultivation of crops in the agro-ecological zone.…”

“… Zimmerman, Gao & Ahn (2011) attributed the positive effect of biochar application on soil CH 4 emissions to the inhibition of soil methanotrophs while Zhu et al (2018) associated reduced soil CH 4 emissions to the change in the ratio of methanogenic to methanotrophic archaea. In general, most studies have found biochar amendments to either decrease or not significantly affect soil N 2 O emissions; however, some few reports have found increased N 2 O emissions following biochar amendments ( Yeboah et al, 2018 ). Explanations for continued long-term suppression of N 2 O emissions in biochar-amended soils include alterations in microbial communities due to physical habitat changes, physical and/or chemical protection of organic C and/or N by biochar and alteration of micro-scale soil redox status due to electrochemical properties of biochars ( Rivka, David & Timothy, 2019 ).…”