Author(s): Shenzhong Tian 1 , Tangyuan Ning 1 , * , Hongxiang Zhao 1 , Bingwen Wang 1 , Na Li 1 , Huifang Han 1 , Zengjia Li 1 , Shuyun Chi 2 , *
CH4 and N2 O play a key role in global climate change . The emission of gas from disturbed soils is an especially important contributory factor to global change . N2 O is emitted from disturbed soil, whereas CH4 is normally oxidized by aerobic soils, making them sinks for atmospheric CH 4 in dry farmland systems . According to estimates of the IPCC , CH 4 and N2 O from agricultural sources account for 50% and 60% of total emissions, respectively. Therefore, it is critical to reduce emissions of greenhouse gases (GHG) from agricultural sources. Many studies have reported that soil tillage has significant effects on CH4 and N2 O emissions from farmland because the production, consumption and transport of CH4 and N2 O in soil are strongly influenced by tillage methods -.
The North China Plain is one of the most important grain production regions of China. Harrow tillage (HT), rotary tillage (RT) and no-tillage (NT) are frequently used conservation tillage methods in this region because they not only improve crop yield but also enhance the utilization efficiency of soil moisture and nutrients -. However, successive years of shallow tillage (10-20 cm) exacerbate the risk of subsoil compaction, which not only leads to the hardening of soil tillage layers and an increase in soil bulk density, but also reduced crop root proliferation, limited water and nutrient availability and reduced crop yield . Subsoiling is an effective method that is used to break up the compacted hardpan layer every 2 or 4 years in HT, RT or NT systems , . Subsoiling significantly increases soil water content and temperature and decreases soil bulk density as well , . These rotation tillage systems are currently utilized in the North China Plain. Soil moisture and temperature are two factors controlling CH 4 and N2 O emissions -. In addition, CH4 and N2 O emissions are normally associated with N application (as fertilizer) under wet conditions .
Collectively, reasonable soil tillage methods may reduce GHG emissions and may be important for developing sustainable agricultural practices . However, it is unclear how conversion to subsoiling would affect CH 4 and N2 O emissions and whether subsoiling increases or reduces GHG emissions and the GWP of these agricultural techniques. In addition, there is little information on the soil factors affecting CH4 and N2 O emissions after conversion to subsoiling in the North China Plain. The aim of this study was to determine whether conversion to subsoiling can reduce CH 4 and N2 O emissions.
Materials and Methods
The research station of this study is a department of Shandong Agricultural University. This study was approved by State Key Laboratory of Crop...