摘要
【目的】探讨干旱区灌溉方式及施肥措施对棉花生长季农田土壤呼吸速率及碳平衡的影响,比较不同管理措施对棉田土壤碳汇强度的影响。【方法】设置滴灌和漫灌两种灌溉方式,在棉花生育期每种灌溉方式设有机肥(OM)、氮磷钾化肥(NPK)、氮磷钾化肥与有机肥配施(NPK+OM)3种施肥处理,以不施肥处理为对照(CK),采用LI-8100土壤碳通量测定仪测定农田土壤呼吸速率,利用根去除法区分根系对土壤呼吸的贡献率,通过计算净生态系统生产力(NEP),分析不同灌溉方式及施肥措施下农田土壤碳汇强度。【结果】不同灌溉方式及施肥措施下农田土壤呼吸速率的季节变化随气温变化均呈先升高后降低的趋势,在7月中旬达到峰值,10月中旬棉花收获后降至最低。不同灌溉方式下农田土壤碳排放量为滴灌>漫灌;相同灌溉方式下不同施肥处理为NPK+OM>OM>CK>NPK。滴灌条件下根系呼吸对土壤呼吸的贡献率为36.38%—58.74%,漫灌条件下为33.73%—52.03%;铃期根系呼吸贡献率最高,生育期平均为48.05%和44.31%。整个棉花生长季节,两种灌溉方式下农田净初级生产力(NPP)均为NPK+OM>NPK>OM>CK。不同管理措施下整个生育期农田土壤均表现为碳"汇",其中,不同灌溉方式下农田碳汇强度为滴灌>漫灌,不同施肥措施为NPK+OM>NPK>OM>CK,灌溉与施肥互作条件下,滴灌方式下NPK+OM处理碳汇强度最强。【结论】在干旱区棉花生产中,采用膜下滴灌节水技术,氮磷钾化肥与有机肥配施并实施秸秆还田等农田管理措施,不仅能增加土壤有机碳含量,培肥地力,提高棉花产量,而且能促进土壤固碳减排。
【Objective】It is of great significance to explore the effects of different irrigation methods and fertilization measures on soil carbon balance in cotton field during cotton growth season in arid region,and to compare the effects of different management practices on soil carbon sequestration intensity in cotton field.【Method】Two-factor experiments with two irrigation methods and four fertilizer treatments were conducted during cotton growth period.Drip irrigation and flood irrigation were arranged as two different irrigation methods and organic manure（OM）,N P K fertilizer（NPK）,combined application of NPK fertilizer and organic manure（NPK＋OM） and no fertilization（CK） were arranged as four fertilizer treatments.Soil respiration rate in cotton field was measured by LI-8100 automated soil CO2 efflux system and root contribution of soil respiration was detected by root exclusion method.Soil carbon sequestration intensity in cotton field under different irrigation methods and fertilization measures was analyzed by calculating net ecosystem productivity（NEP）.【Result】 Under the conditions of different irrigation methods and fertilization measures,seasonal variation of cropland soil respiration rate showed an increase at first,then followed a declining trend with air temperature change.Soil respiration rate reached a peak in mid-July and then reduced to the minimum in mid-October after cotton harvest.Soil carbon emission under drip irrigation was larger than that under flood irrigation,and under the same irrigation condition,the soil carbon emission with NPK＋OM treatment was the highest,then with OM,CK,NPK in turn.The ratio of root respiration contribution to soil respiration was fluctuated between 36.38% and 58.74% under drip irrigation method,whereas between 33.73% and 52.03% under flood irrigation method.Root respiration contribution was the highest at the bolling stage.During the whole growth period,the root respiration contribution under drip irrigation and flood irrigation was ave
出处
《中国农业科学》
CAS
CSCD
北大核心
2012年第12期2420-2430,共11页
Scientia Agricultura Sinica
基金
教育部高等学校博士学科点专项科研基金项目(20116518110002)
国家重点基础研究前期研究专项(2006CB708401)
关键词
干旱区
棉花
土壤呼吸
灌溉
施肥
碳平衡
arid region
cotton
soil respiration
irrigation
fertilization
carbon balance
