摘要
【目的】探究咸淡水组合灌溉对棉田CO_(2)日排放通量的影响。【方法】采用4种水质,即淡水(CK)和矿化度分别为2(S1)、3(S2)、5 g/L(S3)的微咸水;4种咸水淡水灌溉配比,即微咸水∶淡水为1∶1(P1)、1∶4(P2)、4∶1(P3)和1∶0(P4),分析咸淡水组合灌溉对棉田灌水前后土壤CO_(2)日排放特征影响。【结果】①与CK相比,S1、S2、S3处理土壤CO_(2)日平均排放通量分别显著降低了12.64%~24.35%、18.30%~26.69%、22.16%~28.57%(P<0.05)。②CK的土壤CO_(2)累计排放量显著高于其他各处理,S1处理与S2、S3处理土壤CO_(2)累计排放量存在显著差异(P<0.05),但S2、S3处理之间无显著差异(P>0.05)。③相同微咸水矿化度条件下,4种咸水淡水灌溉配比对土壤CO_(2)日平均排放通量影响为P2处理<P1处理<P3处理<P4处理。④土壤CO_(2)排放通量与土壤含水率、土壤温度正相关,与箱内气体温度、土壤pH值、土壤电导率负相关。【结论】选用2 g/L微咸水与淡水按1∶4施配比例灌溉对土壤盐分积累和CO_(2)气体排放影响较小,是灌区合理利用微咸水的一种灌溉方案。
【Objective】In northwestern China,freshwater resources are scarce while saline water is abundant.Irrigation using mixed fresh and saline waters has been adopted as an improved practice to maximize water resource use and sustain agricultural production in this region.This paper is to study the effect of mixed saline and fresh water irrigation on CO_(2)emissions from cotton fields.【Method】Saline waters with salt concentration of 2(S1),3(S2),and 5 g/L(S3)were used in the experiment.Each saline water was mixed with freshwater at four ratios(saline water/freshwater):1∶1(P1),1∶4(P2),4∶1(P3)and 1∶0(P4).The mixed waters were used to drip-irrigate the cottons.The emission of CO_(2)from soil irrigated by different mixed waters was measured daily using static headspace-gas chromatography method.【Result】Compared with freshwater irrigation,irrigation with mixed saline and fresh waters reduced average daily CO_(2)emissions from the soil by 12.64%to 28.57%(P<0.05),depending on the mixture ratio and concentration of the saline water.The cumulative CO_(2)emissions under freshwater irrigation were significantly higher than that from other irrigations.There was a significant difference(P<0.05)in cumulative CO_(2)emissions between the soil irrigated by saline water with salinity of 2 g/L and those irrigated by saline waters with salinity of 3 g/L and 5 g/L.No significant difference in CO_(2)emission was found between soils irrigated by saline waters with salinity of 3 g/L and 5 g/L.When water salinity was the same,the impact of saline-freshwater ratio on daily CO_(2)emissions was ranked in the order of 1∶4<1∶1<4∶1<1∶0.Correlation analysis showed that CO_(2)fluxes from the soils were significantly correlated to temperature,water content,pH and electrical conductivity of the soils.【Conclusion】Mixing freshwater and saline water with salinity of 2 g/L at ratio of 1∶4(saline water/freshwater)had the least effect on soil salt accumulation and CO_(2)emission.It can be used as an effective irrigation practic
作者
李会文
管瑶
贺兴宏
范德宝
王育强
LI Huiwen;GUAN Yao;HE Xinghong;FAN Debao;WANG Yuqiang(School of Water Conservancy and Architectural Engineering,Tarim University,Alar 843300,China;Nanjiang Geotechnical Engineering Research Center of Tarim University,Alar 843000,China)
出处
《灌溉排水学报》
CAS
CSCD
北大核心
2023年第7期60-67,共8页
Journal of Irrigation and Drainage
基金
兵团南疆重点产业创新发展支撑计划项目(2021DB017)
中国农业大学塔里木大学联合基金项目(2019TC157)。
