| In order to solve the problem of inhibiting the growth and development of jujube trees in the low temperature of irrigation water in southern Xinjiang,and to explore the optimal irrigation water temperature for jujube growth.This experiment was conducted in the horticultural test station of Tarim University in 2018 using a single factor multi-level completely randomized test,setting 5 constant temperature water treatments(natural water temperature,10?,20?,30?,40?)test,and in jujube trees.The growth period of the foliage,flowering and fruiting period and fruit growth period were 30 and 10? ?,and three temperature-changing treatments and a 30 °C constant temperature control treatment test were set.The experiment was carried out in a single behavioral community with ten jujube trees per plot,and each plot was cultivated by trough isolation.The jujube trees were irrigated by different irrigation water temperatures,and the soil micro-environment and jujube fruit setting indexes of jujube trees were investigated and analyzed,and the following conclusions were drawn:(1)Warming water irrigation can significantly affect the soil temperature of each soil layer,and the higher the irrigation water temperature,the greater the impact on soil temperature.In the whole growth stage,the treatment of 30 in the 0?-25 cm soil layer is 0.58?,0.54?,0.49?,0.76?,0.77?,respectively,compared with the treatment temperature of 10?;and the soil temperature of 0-10 cm soil layer is affected by temperature change.It is more sensitive,and the soil temperature of 15-25 cm soil layer is sensitive to changes in water temperature.(2)The effect of warming water irrigation on the pH value and conductivity of jujube soil was significant.In April and October,the soil pH of constant temperature and variable temperature treatment showed a trend of “first drop and then rise”,while the soil conductivity showed a trend of “first rise and then fall”,and the change was obvious from June to August.Irrigation water temperature has significant effects on soil nutrients.The treatment of 10 ?water temperature will significantly reduce soil available nitrogen,available phosphorus and available potassium.Different water temperature treatment is sensitive to the accumulation of available nitrogen and available phosphorus in 10-20 cm soil depth.The depth of 0-10 cm and 20-40 cm soil layer is sensitive to the accumulation of available potassium.(3)The effect of warming water irrigation on the fruiting and photosynthetic characteristics of jujube trees was significant.The treatment of water temperature at 30 can ?obviously promote the flowering of jujube trees and increase the fruit setting rate.The net photosynthetic rate and transpiration rate of jujube leaves are unimodal,and the best treatment is at 30?water temperature.When the irrigation water temperature is too high(40?)or too low(10?)will reduce the photosynthetic parameters such as net photosynthetic rate,transpiration rate and water use efficiency of leaves;the SPAD value of jujube leaves will increase with the increase of irrigation water temperature,when the irrigation water temperature exceeds 30?,the SPAD value was significantly reduced.(4)The effect of warming water irrigation on jujube tree yield and fruit quality was significant.The temperature of 30 ?in constant temperature and variable temperature treatment was the best in single fruit weight,yield per mu and fruit diameter.The content of vitamin C and organic acid in jujube fruit increased first and then decreased with the increase of water temperature.When the water temperature reached 40?,The contents of vitamin C,organic acid and soluble sugar were significantly reduced.The treatment at constant temperature of 30 could increase the vitamin C of the fruit,reduce the organic acid,and ?increase the ratio of sugar to acid of the jujube.The content of organic acid in B3 treatment was significantly reduced and soluble sugar content in the temperature change.Higher,its sugar to acid ratio is significantly improved. |
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