中国生态农业学报2018，Vol.26Issue(4)：516-525,10.DOI:10.13930/j.cnki.cjea.170803
施氮和干湿灌溉对水稻抽穗期根系分泌有机酸的影响
Coupling effect of alternate wetting and drying irrigation and nitrogen rate on organic acid in rice root secretion at heading stage
摘要
Abstract
Soil water and nitrogen conditions are the principal factors that affect crop growth and formation. Clarifying effects of soil water and nitrogen conditions and their coupling on grain yield of rice(Oryza sativa L.)have significant implications for high production efficiency and yield. There is extensive domestic and foreign research on the interactions of soil water and fertilizer. Specific focus has been put on ground parameters such as crop growth development, dry shoot formation, physio-logical function, hormone change, nutrient absorption and utilization, water use efficiency, etc. However, there is less work on the characteristics of root secretion, including changes in organic acids in roots. Research on the relationship between organic acid content and nitrogen utilization and the related interactions is also inconsistent and therefore inconclusive. The purpose of this study was to investigate the performance of root secretion under different nitrogen and water regimes and analyze the effect of the interaction of alternate wetting and drying irrigation and nitrogen levels. To that end, a pot-soil experiment was conducted using a mid-season japonica rice cultivar 'Lianjing 7'under different nitrogen rates [ 0N, MN (240 kg?hm-2) and HN (360 kg?hm-2)] and three irrigation regimes [keeping water (0 kPa), alternate wetting and moderate drying (–20 kPa) and alternate wetting and severe drying (–40 kPa)] in 2015 and 2016. The results showed that there was remarkable interaction between nitrogen rate and irrigation regime with the results similar for the two years. Under the same nitrogen rate, tartaric acid, citric acid, oxalic acid, malic acid, succinic acid, total organic acid and amino acid secretion of rice root at heading stage were higher (respectively by 13.2%, 8.7%, 27.3%, 40.0%, 6.7%, 6.3% and 6.4%) in treatment of alternate wetting and moder-ate drying than in treatment of keeping water flood irrigation. The nitrogen agronomic utilization and partial productivity of rice were increased by 4.1% and 1.7% respectively. The secretion amounts of tartaric acid, citric acid, oxalic acid, malic acid and succinic acid at heading stage decreased (respectively by 16.4%, 4.5%, 12.8%, 41.7% and 5.6%) under the treatment of alternate wetting and severe drying than under the treatment of keeping water. This also reduced total organic acid and amino acid in roots and overall nitrogen use efficiency. Under the same irrigation condition, nitrogen application accelerated the root secretion of tartaric acid, acetic acid, malic acid and succinic acid, but decreased the secretion of oxalic acid and citric acid at heading stage of rice. The differences in tartaric acid, acetic acid, malic acid and succinic acid secretion by roots were small be-tween MN and HN treatments. Nitrogen application has positive effects on total organic acid, amino acid, malic acid, succinic acid secretion. Also its interaction effect with alternate wetting and moderate drying was positive, while the interaction effect with alternate wetting and sever was negative. Correlation analysis indicated that citric and oxalic acids secretion by rice roots was significantly positively correlated with nitrogen utilization. However, acetic acid was negatively correlated with nitrogen use effi-ciency. The results of the study suggest that increasing root secretion capacity through appropriate regulation of irrigation coupled with nitrogen rate increased nitrogen use efficiency and thereby promoted high yield of rice.关键词
水稻/干湿交替灌溉/水氮耦合/根系分泌物/有机酸/氮肥利用效率Key words
Rice/Alternate wetting and drying irrigation/Water and nitrogen interaction/Root secretion/Organic acid/Nitrogen efficiency分类
农业科技引用本文复制引用
徐国伟,陆大克,王贺正,贾付俊,陈明灿..施氮和干湿灌溉对水稻抽穗期根系分泌有机酸的影响[J].中国生态农业学报,2018,26(4):516-525,10.基金项目
国家自然科学基金项目(U1304316)、河南省教育厅科学技术研究重点项目(13A210266)、江苏省作物栽培生理重点实验室开放基金(027388003K11009)和河南科技大学学科提升计划A(13660002)资助 This study was supported by the National Natural Science Foundation of China (U1304316), the Key Project for Science and Technology Research of Department of Education of Henan Province (13A210266), the Open Foundation for Key Laboratory of Cultivation and Physi-ology of Jiangsu Province (027388003K11009), and the Henan University of Science and Technology Discipline Improvement and Promotion Plan A (13660002). （U1304316）
