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Biochar application as a tool to decrease soil nitrogen losses ( NH 3 volatilization, N 2 O emissions, and N leaching) from croplands: Options and mitigation strength in a global perspective
Author(s) -
Liu Qi,
Liu Benjuan,
Zhang Yanhui,
Hu Tianlong,
Lin Zhibin,
Liu Gang,
Wang Xiaojie,
Ma Jing,
Wang Hui,
Jin Haiyang,
Ambus Per,
Amonette James E.,
Xie Zubin
Publication year - 2019
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/gcb.14613
Subject(s) - biochar , leaching (pedology) , soil water , environmental science , volatilisation , manure , nitrogen , straw , soil ph , slash and char , soil carbon , greenhouse gas , agronomy , environmental chemistry , chemistry , soil organic matter , soil science , pyrolysis , ecology , organic chemistry , biology
Biochar application to croplands has been proposed as a potential strategy to decrease losses of soil‐reactive nitrogen (N) to the air and water. However, the extent and spatial variability of biochar function at the global level are still unclear. Using Random Forest regression modelling of machine learning based on data compiled from the literature, we mapped the impacts of different biochar types (derived from wood, straw, or manure), and their interactions with biochar application rates, soil properties, and environmental factors, on soil N losses ( NH 3 volatilization, N 2 O emissions, and N leaching) and crop productivity. The results show that a suitable distribution of biochar across global croplands (i.e., one application of <40 t ha −1 wood biochar for poorly buffered soils, such as those characterized by soil pH <5, organic carbon<1%, or clay>30%; and one application of <80 t ha −1 wood biochar, <40 t ha −1 straw biochar, or <10 t ha −1 manure biochar for other soils) could achieve an increase in global crop yields by 222–766 Tg yr −1 (4%–16% increase), a mitigation of cropland N 2 O emissions by 0.19–0.88 Tg N yr −1 (6%–30% decrease), a decline of cropland N leaching by 3.9–9.2 Tg N yr −1 (12%–29% decrease), but also a fluctuation of cropland NH 3 volatilization by −1.9–4.7 Tg N yr −1 (−12%–31% change). The decreased sum of the three major reactive N losses amount to 1.7–9.4 Tg N yr −1 , which corresponds to 3%–14% of the global cropland total N loss. Biochar generally has a larger potential for decreasing soil N losses but with less benefits to crop production in temperate regions than in tropical regions.