title: [Impact of land use change and cultivation measures on soil organic carbon (SOC) and its 13C values].
abstract: In Quzhou County, Hebei Province where now intensive farming system is operated, original grassland and farming land under different tillage, crop straw return and fertilization measures were studied using isotope carbon for the analysis of the impact on soil organic carbon (SOC) properties. The research indicated that after change into farmland (34 years), SOC is significantly reduced and for 1 m of soil layer, the scope of reduction is from 13.3%-35% and this decrease happens in 0-40 cm of soil layer. After 8 years of fertilization, SOC can be increased at 0.83 g x kg(-1). No-tillage can significantly increase the SOC especially in 0-10 cm but plough will increase the SOC at 10-15 cm and 15-20 cm. Change of delta13 C of SOC due to land use change mainly happens in 0-20 cm, where input of organic materials from maize stored. In soil layer of 0-5 cm, only maximum 18% of SOC is from crop residues and in 15-20 cm, this percentage is about 5%.
authors.affiliation: College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China. mengfq@cau.edu.cn
authors.forename: Fan-qiao
authors.initials: FQ
authors.lastname: Meng
authors.forename: Xing
authors.initials: X
authors.lastname: Kuang
authors.forename: Zhang-liu
authors.initials: ZL
authors.lastname: Du
authors.forename: Wen-liang
authors.initials: WL
authors.lastname: Wu
authors.forename: Yan-bin
authors.initials: YB
authors.lastname: Guo
mesh_terms: D000383:Agriculture / Q000379:methods*; D002244:Carbon / Q000032:analysis*; D002247:Carbon Isotopes / Q000032:analysis*; D002681:China; D018556:Crops, Agricultural / Q000254:growth & development; D005308:Fertilizers; D009930:Organic Chemicals / Q000032:analysis*; D006109:Poaceae / Q000254:growth & development; D012987:Soil / Q000032:analysis*; D003313:Zea mays / Q000254:growth & development
chemical_list: D002247:Carbon Isotopes; D005308:Fertilizers; D009930:Organic Chemicals; D012987:Soil; D002244:Carbon