Effect Of Fruit Tree Hole Storage Brick On Growth And Nitrogen Absorption Efficiency Of Soft Seed Pomegranate In Greenhouse Of Southern Xinjiang

【Objective】To explore the effects of fruit tree hole storage brick on the growth and development,photosynthetic characteristics,soil nitrogen absorption and soil characteristics of greenhouse soft seed pomegranate in sandy land of southern Xinjiang,and to provide theoretical basis for the efficient cultivation of facility fruit trees in sandy land of southern Xinjiang.【Method】In this experiment,3-year-old‘Tunisian’soft seed pomegranate cultivated in a greenhouse under sandy conditions in Hotan prefecture of southern Xinjiang was used as experimental material.Nitrogen was dribbled into fruit hole storage brick（with three treatments:a（T1）,b（T2）and CK）at 10 and40 days after application.To investigate its effects on growth,photosynthetic characteristics,soil nitrogen uptake and soil characteristics of‘Tunisian’soft seed pomegranate planted in sandy land in southern Xinjiang.【Results】1.Adding nitrogen drops to the fruit tree hole storage brick could significantly improve the shoot length and coarseness,petiole length,coarseness,inter node length,leaf growth and biomass accumulation of‘Tunisian’soft seed pomegranate.After 70 days of treatment,the new shoot length of fruit tree hole storage brick a and b was significantly increased than that of fruit tree hole storage brick,and the growth of new shoot thickness and petiole length was the most obvious than that of CK at 50 days.On day70 after treatment,petiole thickness in treatments T1 and T2 grew the fastest than that in CK,and inter node length in treatments T1 and T2 grew the fastest than that in CK at day 40.2.T1 and T2 treatments significantly promoted the leaf nitrogen balance index,chlorophyll and flavonoid content of soft seed pomegranate.The chlorophyll effect was better at 3d,and T1 increased by7.32%and 13.21%compared with T2 and CK,respectively.Flavonoid and nitrogen balance index were better at 5 days.When the light intensity was between 12:00 and 16:00,the net photosynthetic rate showed two significant peaks,one of which reached 12.51μmol/（m²·s）and the other reached9.64μmol/（m²·s）.The inter cellular CO₂concentration was the highest and lowest at 10:00 and 14:00.The stomatal conductance reached its maximum at 10:00,and the order was T1>T2>CK.At 16:00,all treatments reached the maximum transpiration rate,and T1 and T2 were significantly higher than CK.At10:00,the instantaneous water utilization rate of each treatment was the highest compared with other time periods,and T1 and T2 were significantly higher than CK,with changes of 82.22%and 36.84%compared with CK,respectively.The treatment at 16:00 was the lowest compared with other time.The soil moisture content in shallow soil was lower at 20 cm and higher at 40 cm.3.T1 and T2 treatments significantly increased the content of mineral elements in the roots,shoots and leaves of soft seed pomegranate.The contents of total N and K in roots and leaves were T1>T2>CK,and the contents of total P in shoots were T2>T1>CK.In addition,T1 and T2 treatments significantly increased the content of alkali-hydrolyzed nitrogen in 20-40 cm soil layer and the content of available potassium in 40-60 cm soil layer.The highest available phosphorus content was 41.80%and 44.61%in the40-60 cm soil layer,and in the 0-20 cm soil layer,organic matter had the greatest concentration.The leaves,both 0.03 g·kg^-1,had the greatest nitrate and ammonium nitrogen content.The shoot had the most ammonium nitrogen,while the root and root had the most nitrate and ammonium nitrogen,with a ratio of T2.>T1>CK.The soil total nitrogen content in the 0-80 cm soil layer was the highest in the 0-20 cm soil layer.4.Two consecutive years of experiments showed that T1 and T2 could significantly improve plant growth.In 2022,the soil layer of 20-40 cm was T2>T1>CK.T2>T1>CK in the 20-60 cm soil layer in2021.In 2022,the nitrogen content in 0-80 cm soil layer was different from that in 2021.The decrease of In 2022,available potassium at T1 and T2 treatments in 0-80 cm soil layer decreased by 4.57%and 3.37%compared with 2021,while available phosphorus decreased by 10.40%and 15.18%compared with 2021,respectively.In the 0-80cm soil layer,the annual alkali-hydrolyzed nitrogen in 2022 was 7.76%lower than that in 2021,while the organic matter was 10.23%higher than that in 2021.After one irrigation cycle,the water content in the 0-40 cm soil layer decreased slowly in 2022;the water content in the 0-80 cm soil layer after T1 and T2 treatments in 2021 decreased more slowly than that in CK;the water content in the40-60cm soil layer was higher than that in CK.The soil water content in the 0-80 cm soil layer in 2021decreased the water loss compared with that in 2022,and it was most significant in the 20-40 cm soil layer.【Conclusion】The application of fruit tree hole storage brick combined with nitrogen fertilizer can promote the growth of‘Tunisian’soft seed pomegranate planted in greenhouse under sandy conditions in southern Xinjiang.The soil environment of strong alkaline sandy land in southern Xinjiang could be further improved by increasing plant soil physical and chemical properties and nitrogen absorption.It is concluded that T1 treatment has the best effect.