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sur le développement des zones arides et semi-arides

Titre : Study on the Optimal Regulated Deficit Irrigation and Fertilization System of Drip Irrigation Jujube in Arid Oasis Area

Auteur : 艾鹏睿

Grade : Doctoral Dissertation 2022

Université : Xinjiang Agricultural University

Résumé partiel
In response to the severe water shortage and high potassium fertilizer consumption in agricultural production in Xinjiang,a 6-year field experiment on irrigation and fertilization of jujube trees from 2016-2021 was conducted at the forestry fruit industry experimental site of Xinjiang Agricultural University in Team 10,Hongqipo,Aksu Prefecture,Xinjiang.In particular,the jujube tree is the featured fruit tree of Xinjiang.Based on the fixed-position observation using advanced equipment such as a large-scale weighing evapotranspiration meter and a photosynthesis meter,a systematic study on water consumption,physiology,yield and quality of jujube trees was conducted.The water deficit compensation mechanism of jujube trees was revealed.The water-nutrient-yield-quality response relationship of jujube trees was clarified.The reliability of three evapotranspiration estimation models in jujube trees with drip irrigation in arid zone was verified.The applicability of three CWSI models in the diagnosis of water deficit of jujube trees was evaluated.Based on the thorough investigation of the composition of production factors,a comprehensive efficiency evaluation system for jujube trees was constructed.（1）Under the same fertilizer application,mild（75%ETc）and severe（50%ETc）water deficit significantly reduced evapotranspiration of jujube trees by 4.75%-5.24%and 16.27%-18.54%,respectively.Under the same irrigation quota,reduced potassium fertilizer application（50%K2O）resulted in a 2.73%-3.58%reduction in evapotranspiration of jujube trees,whilst increased potassium fertilizer application（150%K2O）had no significant effect on evapotranspiration（P>0.05）.Therefore,the effect of water deficit on jujube trees was significantly higher than that of fertilizer application.Fertilizer tends to indirectly affect evapotranspiration of jujube trees by affecting plant physiological development.（2）Water deficit applied at the flowering and young fruit stages had significantly lower effects on SPAD values,net photosynthetic rate and transpiration rate of leaves sensitive to water changes than at the fruit expansion stage（P<0.05）.The application of water deficit during the flowering and young fruit stages was beneficial in reducing growth redundancy（e.g.,a decrease of 4.03%-14.55%in the growth of fruit-bearing shoots and 10.95%-26.17%in plant height）.The fruit expansion stage is a critical water demand period for fruit trees,and the application of mild（75%ETc）and severe（50%ETc）water deficits significantly reduced the net photosynthetic rate by 7.98%and 21.75%during this reproductive period,respectively.The rehydration after water deficit could repair the damage to plants caused by water deficit ;with a longer duration,it exhibited larger repair effects on water-sensitive indicators,whilst the effects on water-insensitive indicators were not significant.

Présentation (CNKI)