title: Interactive effects of straw-derived biochar and N fertilization on soil C storage and rice productivity in rice paddies of Northeast China.
abstract: Impacts of biochar on greenhouse gas emissions and C sequestration in agricultural soils have been considered as the key to mitigate climate change. There is limited knowledge regarding the effects of rice straw-derived biochar and interaction with N fertilization on soil C sequestration and rice productivity in fertile paddy fields. A 2-year (2013 and 2014) consecutive field trial was performed using straw treatment (5.05 t ha(-1)) and biochar amendment (0, 1.78, 14.8 and 29.6 t ha(-1)) with or without urea application in a rice paddy in Northeast China. A super high yielding rice variety (Oryza sativa L. subsp. Japonica cv. 'Shennong 265') was cultivated with permanent flooding. Results showed that biochar amendments significantly decreased CH4 emissions relative to straw treatment irrespective of N fertilization, especially in N-fertilized soils with 1.78 t ha(-1) biochar. There were no differences in CO2 emissions with respect to biochar amendments, except for 14.8 t ha(-1) biochar with N fertilization. Straw treatment had the highest global warming potential over a 100-year time frame, which was nearly 1.5 times that of 14.8 t ha(-1) biochar amendment without N fertilization. Biochar addition increased total soil C by up to 5.75 mg g(-1) and 11.69 mg g(-1) (with 14.8 and 29.6 t ha(-1) biochar, respectively), whereas straw incorporation increased this value by only 3.92 mg g(-1). The aboveground biomass of rice in biochar-amended soils increased to varying degrees compared with that in straw-treated soils. However, biochar application had no effects on rice yield, regardless of N fertilization. This study indicated that transforming straw to biochar was more stabilized and more suitable to mitigate greenhouse gas emissions and increase C storage in agriculture soils in Northeast China.
authors.affiliation: Rice Research Institute, Shenyang Agricultural University, Shenyang 110866, China.
authors.forename: Yanghui
authors.initials: Y
authors.lastname: Sui
authors.affiliation: Rice Research Institute, Shenyang Agricultural University, Shenyang 110866, China; Liaoning Biochar Engineering & Technology Research Center, Shenyang Agricultural University, Dongling Rd, Shenyang 110866, China.
authors.forename: Jiping
authors.initials: J
authors.lastname: Gao
authors.affiliation: Rice Research Institute, Shenyang Agricultural University, Shenyang 110866, China.
authors.forename: Caihong
authors.initials: C
authors.lastname: Liu
authors.affiliation: Rice Research Institute, Shenyang Agricultural University, Shenyang 110866, China.
authors.forename: Wenzhong
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Liaoning Biochar Engineering & Technology Research Center, Shenyang Agricultural University, Dongling Rd, Shenyang 110866, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Lan
authors.affiliation: Rice Research Institute, Shenyang Agricultural University, Shenyang 110866, China.
authors.forename: Shuhang
authors.initials: S
authors.lastname: Li
authors.affiliation: Liaoning Biochar Engineering & Technology Research Center, Shenyang Agricultural University, Dongling Rd, Shenyang 110866, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Meng
authors.affiliation: Rice Research Institute, Shenyang Agricultural University, Shenyang 110866, China. Electronic address: xuzhengjin@126.com.
authors.forename: Zhengjin
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Rice Research Institute, Shenyang Agricultural University, Shenyang 110866, China. Electronic address: tl_rice@126.com.
authors.forename: Liang
authors.initials: L
authors.lastname: Tang
keywords: Biochar; Greenhouse gas emissions; Rice paddy; Soil total carbon