摘要
为探究不同水文年型下稻田最优的水碳管理模式,基于2 a田间试验数据校正并验证了DNDC模型,选取了3种典型的水文年,模拟了不同灌溉模式和秸秆还田水平下稻田土壤有机碳(SOC)和水稻产量的变化,并对结果进行了比选。结果表明:DNDC模型可以较好地模拟节水灌溉条件下稻田SOC和水稻产量变化;灌溉模式影响了稻田SOC和水稻产量,相同秸秆还田水平下,控灌稻田0~10 cm土层SOC略低于淹灌处理,但水稻产量更高,控灌稻田的SOC和水稻产量分别较淹灌稻田降低了0.25%~1.92%和增加了0.32%~8.13%。随着秸秆还田水平的提高,不同水文年的稻田SOC均呈阶梯状上升趋势,但水稻产量和水分生产率的结果存在差异,平水年呈先升高后稳定的趋势,在6500 kg·hm^-2秸秆还田水平下达到峰值,丰水年条件下秸秆还田的增产作用较枯水年更为明显。与1000 kg·hm^-2的秸秆还田水平相比,8000 kg·hm^-2秸秆还田水平下水稻产量和水分生产率在1964年(枯水年)分别增加了1.95%和2.27%,而在1977年(丰水年)分别增加了4.36%和4.38%。节水灌溉与秸秆还田耦合是值得推荐的水碳管理模式,平、枯、丰水年的推荐秸秆还田水平分别为6000、6000 kg·hm^-2和7500 kg·hm^-2,SOC和产量达到潜力的99.2%和89.8%以上,水分生产率较相同秸秆还田量的淹灌处理高43.5%以上。
In order to explore the optimal water and carbon management modes for paddy fields in different hydrological years,the DNDC model was verified and validated based on data from two years of field experiments.Three typical hydrological years were selected to simulate the influences of different irrigation modes and straw-return levels on soil organic carbon(SOC)and rice yield in the lower paddy field.The results showed that DNDC model well simulated SOC and rice yield dynamics under controlled irrigation.Different irrigation modes affected SOC and rice yield,while the SOC of the 0~10 cm soil layer in the CS treatment was slightly lower than that in FS(0.25%~1.92%),but the rice yield was higher than FS(0.32%~8.13%).With the improvement of straw returning level,the SOC in different hydrological years showed a gradually rising trend,but the results of rice yield and water productivity were different.In the normal year,the“S”curve appeared first rising and then stable,and reached the peak at the level of 6500 kg·hm^-2 of straw returning to the paddy field.In the wet year,straw returning increased rice yield more significantly than that in dry year.Compared with 1000 kg·hm^-2,the rice yield and water productivity of 8000 kg·hm^-2increased by 1.95%and 2.27%in 1964(dry year),and 4.36%and 4.38%in 1977(dry year).Therefore,the coupling of water-saving irrigation and straw returning was a recommended water and carbon management mode.The recommended straw returning levels were 6000,6000,and 7500 kg·hm^-2 in normal,dry,and wet years,respectively.At this time,the SOC and yield reached 99.2%and 89.8%of the potential,respectively,and the water productivity was 43.5%higher than that of flooding treatment.
作者
江赜伟
杨士红
丁洁
孙潇
JIANG Zewei;YANG Shihong;DING Jie;SUN Xiao(College of Agricultural Science and Engineering,Hohai University, Nanjing, Jiangsu 210098, China;State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, Jiangsu 210098, China)
出处
《干旱地区农业研究》
CSCD
北大核心
2020年第4期93-102,共10页
Agricultural Research in the Arid Areas
基金
国家自然科学基金(51879076)
中央高校业务费项目(2019B67814)
江苏省研究生科研创新计划(SJKY19_0525)
江苏省高校优秀科技创新团队项目。
关键词
稻田
节水灌溉
秸秆还田
土壤有机碳
水文年型
产量
水分生产率
DNDC模型
paddy field
water-saving irrigation
straw return
soil organic carbon
hydrological year
yield
water productivity
DNDC model
