title: Enhanced rice production but greatly reduced carbon emission following biochar amendment in a metal-polluted rice paddy.
abstract: Soil amendment of biochar (BSA) had been shown effective for mitigating greenhouse gas (GHG) emission and alleviating metal stress to plants and microbes in soil. It has not yet been addressed if biochar exerts synergy effects on crop production, GHG emission, and microbial activity in metal-polluted soils. In a field experiment, biochar was amended at sequential rates at 0, 10, 20, and 40 t ha(-1), respectively, in a cadmium- and lead-contaminated rice paddy from the Tai lake Plain, China, before rice cropping in 2010. Fluxes of soil carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) were monitored using a static chamber method during the whole rice growing season (WRGS) of 2011. BSA significantly reduced soil CaCl2 extractable pool of Cd, and DTPA extractable pool of Cd and Pb. As compared to control, soil CO2 emission under BSA was observed to have no change at 10 t ha(-1) but decreased by 16-24% at 20 and 40 t ha(-1). In a similar trend, BSA at 20 and 40 t ha(-1) increased rice yield by 25-26% and thus enhanced ecosystem CO2 sequestration by 47-55% over the control. Seasonal total N2O emission was reduced by 7.1, 30.7, and 48.6% under BSA at 10, 20, and 40 t ha(-1), respectively. Overall, a net reduction in greenhouse gas balance (NGHGB) by 53.9-62.8% and in greenhouse gas intensity (GHGI) by 14.3-28.6% was observed following BSA at 20 and 40 t ha(-1). The present study suggested a great potential of biochar to enhancing grain yield while reducing carbon emission in metal-polluted rice paddies.
authors.affiliation: Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture; College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, China.|Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China.
authors.forename: Afeng
authors.initials: A
authors.lastname: Zhang
authors.affiliation: Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China.
authors.forename: Rongjun
authors.initials: R
authors.lastname: Bian
authors.affiliation: Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China.
authors.forename: Lianqing
authors.initials: L
authors.lastname: Li
authors.affiliation: Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture; College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture; College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Soil Science and Soil Water Conservation, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, Pakistan.
authors.forename: Qaiser
authors.initials: Q
authors.lastname: Hussain
authors.affiliation: Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China. pangenxing@yahoo.com.cn.
authors.forename: Genxing
authors.initials: G
authors.lastname: Pan
mesh_terms: D000383:Agriculture / Q000379:methods*; D000393:Air Pollutants / Q000032:analysis; D000397:Air Pollution; D018533:Biomass; D002104:Cadmium / Q000032:analysis; D002244:Carbon; D002245:Carbon Dioxide / Q000032:analysis*; D002606:Charcoal / Q000494:pharmacology*; D002681:China; D004787:Environmental Pollution; D017752:Greenhouse Effect; D007854:Lead / Q000032:analysis; D008670:Metals; D008697:Methane / Q000032:analysis; D009609:Nitrous Oxide / Q000032:analysis*; D012275:Oryza / Q000187:drug effects / Q000254:growth & development*; D012987:Soil
chemical_list: D000393:Air Pollutants; D008670:Metals; D012987:Soil; C540010:biochar; D002104:Cadmium; D002245:Carbon Dioxide; D002606:Charcoal; D007854:Lead; D002244:Carbon; D009609:Nitrous Oxide; D008697:Methane
keywords: Greenhouse gas emissions; Metal contamination; Net greenhouse gas balance; Rice paddy; Wheat-straw-derived biochar