烟草科技2016，Vol.49Issue(2)：1-6,6.
外源有机14C对烟稻轮作土壤有机质特性的影响
Effects of exogenous organic 14C on soil organic matter properties in tobacco-rice rotation fields
摘要
Abstract
To study the decomposition and transformation patterns of exogenous organic carbon after returning to fields and investigate the effects on the constitution, transformation and characteristics of organic matters in the soil of tobacco-rice rotation fields, 14C-labelled ryegrass roots were added into tobacco planting soils at the rates of 0, 0.3% and 0.6% and cultured with carborundum tubes. The results showed that: 1) The decomposition of exogenous organic 14C proceeded rapidly at the early period and then slowed down, its mineralization rate was over 50% during whole flood-drought cultivation, between 20%-30% during drought cultivation and about 30% during flood cultivation, respectively. 2) Due to continuous tobacco cropping, the content and quality of soil organic matter (SOM) decreased. Exogenous organic 14C did not significantly affect the content of SOM, however, the composition and characteristics of organic matter changed greatly, for example, the proportion of humic acid (HA) increased. 3) The quantities of HA and fulvic acid (FA) transformed by endogenous organic C and exogenous organic 14C were in dynamic equilibrium during drought cultivation. While the quantity of FA transformed by exogenous organic 14C and the humification coefficient of SOM increased during flood cultivation. These results suggest that straw returning and tobacco-rice rotation are the effective cultural measures for improving the quality of SOM in tobacco fields.关键词
烟草/烟稻轮作/秸秆还田/14C同位素/土壤/有机质Key words
Tobacco/Tobacco-rice rotation/Straw returning/14C isotope/Soil/Organic matter分类
农业科技引用本文复制引用
易建华,彭宇,王修忠,蒲文宣,周曙光..外源有机14C对烟稻轮作土壤有机质特性的影响[J].烟草科技,2016,49(2):1-6,6.基金项目
国家烟草专卖局面上项目"烟草连作的土壤肥力制约因子及其保育措施研究"(2008YC0003) （2008YC0003）
湖南中烟工业有限责任公司科技项目"基于生物技术降低烟碱的关键技术研究"(KY2012YC0001). （KY2012YC0001）
