Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Accumulation Characteristics and Optimal Regulation of Water,Salt and Nutrient in Film-Mulched Cotton （Gossypium Hirsutum L.） Field Under Drip Irrigation in Arid Area

Auteur : 衡通

Grade : Doctoral Dissertation 2022

Université : Shihezi University

Résumé partiel
The interaction between farmland water and salt and nutrients in arid areas and the environmental problems such as soil salinization and chemical fertilizer residue are the current international research hotspots.The technology of drip irrigation under mulch solves the problem of transforming desert into oasis in arid area of Xinjiang,and realizes the effect of water saving,fertilizer saving,yield increasing and land saving.However,long-term drip irrigation under mulch changed the water cycle process of farmland ecosystem,resulting in the particularity of salt and nutrient distribution in time and space,and environmental problems such as soil salt stress and fertilizer accumulation.In this thesis,the farmland ecosystem under mulched drip irrigation in Manas River Basin of Xinjiang was taken as the research object.The basin scale（Manas River Basin investigation）,rhizosphere scale（site test）and field scale（farmland drainage and salt drainage project）were combined.The spatial variation characteristics,accumulation status and migration mechanism of water and salt and nutrients in the farmland ecosystem under mulched drip irrigation in arid areas were quantitatively revealed by regional variable theory,15N isotope tracer technology,and the synergistic drip irrigation and leaching project of shaft and pipe drainage.To clarify the nutrient absorption mechanism of cotton under rhizosphere soil salt stress and the interaction effect and synergistic mechanism between soil water and salt and nutrients ;to explore the improvement effect and soil salt balance law of saline soil under water conservancy improvement measures.In order to provide theoretical basis and scientific support for the efficient utilization of water and fertilizer under mulched drip irrigation and the management of water resources and environmental safety in arid areas of Xinjiang,the research conclusions of this thesis mainly include the following three aspects :（1）Watershed scale spatial pattern.In 2019-2020,the soil salinity in Manas River Basin showed strong spatial variability and weak spatial autocorrelation,and the random probability affected by soil,topography and day and night warming was small,but it would not cause the change of spatial heterogeneity of soil total nitrogen content.

Mots clés : soil salinization ;drip irrigation under film ;15N isotope ;subsurface pipe drainage ;soil salt stress ;

Présentation (CNKI)