title: Response of CH4 and N2O emissions and wheat yields to tillage method changes in the North China plain.
abstract: The objective of this study was to quantify soil methane (CH(4)) and nitrous oxide (N(2)O) emissions when converting from minimum and no-tillage systems to subsoiling (tilled soil to a depth of 40 cm to 45 cm) in the North China Plain. The relationships between CH(4) and N(2)O flux and soil temperature, moisture, NH(4) (+)-N, organic carbon (SOC) and pH were investigated over 18 months using a split-plot design. The soil absorption of CH(4) appeared to increase after conversion from no-tillage (NT) to subsoiling (NTS), from harrow tillage (HT) to subsoiling (HTS) and from rotary tillage (RT) to subsoiling (RTS). N(2)O emissions also increased after conversion. Furthermore, after conversion to subsoiling, the combined global warming potential (GWP) of CH(4) and N(2)O increased by approximately 0.05 kg CO(2) ha(-1) for HTS, 0.02 kg CO(2) ha(-1) for RTS and 0.23 kg CO(2) ha(-1) for NTS. Soil temperature, moisture, SOC, NH(4) (+)-N and pH also changed after conversion to subsoiling. These changes were correlated with CH(4) uptake and N(2)O emissions. However, there was no significant correlation between N(2)O emissions and soil temperature in this study. The grain yields of wheat improved after conversion to subsoiling. Under HTS, RTS and NTS, the average grain yield was elevated by approximately 42.5%, 27.8% and 60.3% respectively. Our findings indicate that RTS and HTS would be ideal rotation tillage systems to balance GWP decreases and grain yield improvements in the North China Plain region.
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, Shandong PR, China.
authors.forename: Shenzhong
authors.initials: S
authors.lastname: Tian
authors.forename: Tangyuan
authors.initials: T
authors.lastname: Ning
authors.forename: Hongxiang
authors.initials: H
authors.lastname: Zhao
authors.forename: Bingwen
authors.initials: B
authors.lastname: Wang
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Huifang
authors.initials: H
authors.lastname: Han
authors.forename: Zengjia
authors.initials: Z
authors.lastname: Li
authors.forename: Shuyun
authors.initials: S
authors.lastname: Chi
mesh_terms: D000383:Agriculture / Q000379:methods*; D018533:Biomass; D002244:Carbon / Q000032:analysis; D002681:China; D017752:Greenhouse Effect; D006863:Hydrogen-Ion Concentration; D008697:Methane / Q000032:analysis*; D009609:Nitrous Oxide / Q000032:analysis*; D012987:Soil / Q000032:analysis*; D013696:Temperature; D014908:Triticum / Q000254:growth & development*; D014867:Water / Q000032:analysis
chemical_list: D012987:Soil; D014867:Water; D002244:Carbon; D009609:Nitrous Oxide; D008697:Methane