Effects Of Recirculating Aerated Ground Penetration Irrigation On Growth,Yield And Quality Of Cucumber In Greenhouse

Traditional agricultural irrigation method is very easy to cause insufficient aeration of soil and low oxygen content in crop root zone,which will affect the absorption and utilization of water and nutrients by crop roots.This test takes greenhouse cucumber as the research object,aerates the irrigation water through the circulating aeration irrigation device,and evenly conveys the aerated water to crop root zone through underground seepage irrigation,improve crop soil growth environment,improve cucumber yield and improve quality as the goal.Four aeration levels,high,medium,low and non-aeration,three fertilization levels,severe deficit,medium deficit and suitable three irrigation levels were designed.Three-factor mixed orthogonal test design was adopted for 12 treatments.The effects of different aeration,fertilization and irrigation on plant height,stem diameter,leaf area,chlorophyll,root activity,dry matter accumulation,yield and quality of greenhouse cucumber were studied.The following main conclusions were obtained:(1)Recirculating aeration underground seepage irrigation can promote the growth and development of cucumber plants in the early and middle stages.At the same level of fertilization and irrigation,with the increase of aeration,cucumber plant height,stem diameter and leaf area increased gradually.Higher aeration treatment increased plant height,stem diameter and leaf area by 9.81%,17.94% and 9.32% respectively compared with non-aeration treatment.With the increase of fertilization level under the same aeration irrigation level,plant height,stem diameter,leaf area and chlorophyll of cucumber showed an increasing trend.At the same aeration fertilization level,irrigation amount had no significant effect on early growth stage of cucumber.Under the interaction,aeration and fertilization had significant effects on plant height,stem diameter and leaf area of cucumber(P<0.01);aeration and irrigation had significant effects on plant height,stem diameter and chlorophyll content(P <0.05);aeration and irrigation had no significant effects on leaf area(P>0.05).(2)Recirculating aeration underground seepage irrigation can promote the growth and development of cucumber roots and improve their vigor.Root activity of high aeration treatment was significantly higher than that of medium,low and non-aeration treatment at the same level of fertilization and irrigation,and it was 16.43% higher than that of non-aeration treatment.At the same amount of aeration irrigation during flowering and fruit-sitting period,different fertilization levels had no significant effect on cucumber root activity(P>0.05).During fruit enlargement period and maturity period,root activity gradually increased with the increase of fertilization level,high fertilization level increased by 12.47% compared with low fertilization level,and different irrigation levels significantly affected root activity,reaching a very significant level at maturity(P<0.01).(3)Recirculating aeration underground infiltration can significantly improve soil enzyme activity.Enzyme activities in soils with high aeration reached the highest values at the same level of fertilization and irrigation.During different growth periods,the activity of urease and alkaline phosphatase increased gradually with the increase of fertilization level under the same aeration irrigation level,and the activity of urease and alkaline phosphatase was the highest under high fertilization level,while the activity of catalase increased first and then decreased with the increase of fertilization level during fruit enlargement period.Trend,at maturity stage,with the improvement of fertilization level,there was no significant difference(P > 0.05).At the same level of aeration,the enzymatic activity gradually increased during fruit enlargement and maturation stages with the increase of irrigation water.Under the interaction,soil enzymatic activity was highest under the suitable amount of irrigation with high aeration fertilization level.(4)Circulating aeration underground infiltration can increase the number of soil microorganisms(bacteria,fungi,actinomycetes).At the same level of fertilization and irrigation,the number of microorganisms in soil treated with high aeration reached the maximum.The number of soil microorganisms increased with the increase of fertilization level in flowering and Fruit-setting stage and maturing stage,but increased first and then decreased during fruit enlargement stage with the increase of fertilization level.Increase of irrigation volume during flowering and fruit setting period had no significant effect on soil microbial quantity(P>0.05).During fruit enlargement and maturation period,the number of soil microorganisms gradually increased with the increase of irrigation volume.Under the interaction,the optimum combination treatment of high aeration and irrigation during fruit enlargement period had the largest amount of microorganisms.(5)Circulating aeration underground seepage irrigation significantly increases dry matter accumulation and yield of cucumber.Among them,dry matter above ground in high aeration treatment increased by 10.3% compared with non-aeration treatment;dry matter under ground increased by 16.9%;yield per plant in high aeration treatment increased by 20.7% compared with non-aeration treatment;at the same aeration level,dry matter accumulation above ground and below ground increased gradually with the increase of fertilizer application;at the same aeration level,maturity of cucumber increased with the increase of irrigation water.Yield and dry matter accumulation both increased.(6)Circulating aeration underground seepage irrigation can improve the quality of cucumber fruit.At the same irrigation and fertilization level,the quality index(vitamin C,sugar-acid ratio,soluble sugar,soluble protein)of cucumber fruit reached the highest value under high aeration.Among them,high aeration treatment had significant effect on vitamin C content(P<0.01).Fertilization had significant effect on vitamin C content of cucumber(P<0.05).High fertilization level significantly increased by 18.3% compared with low fertilization level.Irrigation quantity under single factor had no significant effect on VC content in Cucumber quality.High aeration and high fertilization treatment had the best quality of Cucumber Fruit under interaction.In conclusion,the coupled irrigation mode of cyclic aeration and underground seepage irrigation with fertilizer and air is beneficial to the growth and development of cucumber,the yield of cucumber and the quality of fruit.The results of this experiment show that the combination treatment of high aeration and fertilization with suitable irrigation volume has the best effect on the growth and physiological index,yield and quality of greenhouse cucumber.