title: [An evaluation of net carbon sink effect and cost/benefits of a rice-rape rotation ecosystem under long-term fertilization from Tai Lake region of China].
abstract: Taking a long-term fertilized rice-rape rotation system in Taihu Lake as test objective, its annual C balance and economic benefit were estimated, based on the measurement of past years grain yield, litter C content, and field CO2 emission as well as the investigation of material and management inputs. The calculated annual C sink under different fertilizations ranged from 0.9 t C x hm(-2) x a(-1) to 7.5 t C x hm(-2) x a(-1), and the net C sink effect under combined inorganic/organic fertilization was three folds as that under chemical fertilization. The C cost of material input ranged from 0.37 t C x hm(-2) x a(-1) to 1.13 t C x hm(-2) x a(-1), and that of management input ranged from 1.69 t C x hm(-2) x a(-1) to 1.83 t C x hm(-2) x a(-1). The annual economic benefit ranged from 5.8 x 10(3) CNY x hm(-2) x a(-1) to 16.5 x 10(3) CNY x hm(-2) x a(-1), and was 2.1 times higher under combined fertilization than under chemical fertilization. Comparing with that under chemical fertilization, the marginal cost for per ton C sink under combined inorganic/organic fertilization was estimated as 217.1 CNY x t(-1) C, very close to the C price of 20 Euro x t(-1) C in the EU. In sum, under combined inorganic/organic fertilization, this rice paddy ecosystem could not only have higher productivity, but also present greater net C sink effect and higher economic benefit, compared with under chemical fertilizer fertilization.
authors.affiliation: Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China. yuyiqingchen_123@yahoo.com
authors.forename: Jie-Jing
authors.initials: JJ
authors.lastname: Li
authors.forename: Gen-Xing
authors.initials: GX
authors.lastname: Pan
authors.forename: Xu-Hui
authors.initials: XH
authors.lastname: Zhang
authors.forename: Qing-Hua
authors.initials: QH
authors.lastname: Fei
authors.forename: Zhi-Peng
authors.initials: ZP
authors.lastname: Li
authors.forename: Ping
authors.initials: P
authors.lastname: Zhou
authors.forename: Ju-Feng
authors.initials: JF
authors.lastname: Zheng
authors.forename: Duo-Sheng
authors.initials: DS
authors.lastname: Qiu
mesh_terms: D000383:Agriculture / Q000379:methods*; D029741:Brassica rapa / Q000254:growth & development*; D002244:Carbon / Q000032:analysis* / Q000737:chemistry; D002245:Carbon Dioxide / Q000032:analysis*; D002681:China; D003362:Cost-Benefit Analysis; D004463:Ecology / Q000191:economics; D017753:Ecosystem; D004784:Environmental Monitoring; D005308:Fertilizers; D012275:Oryza / Q000254:growth & development*
chemical_list: D005308:Fertilizers; D002245:Carbon Dioxide; D002244:Carbon