Water And Fertilizer Coupling Effects On Growth Of Blueberry And Fruit

Five-year-old Vaccinium ashei “Britewell” were taken as materials,set twelve treatments,three fertilizer levels and four water levels,a total of twelve,to study the effects of water and fertilizer coupling on the growth,nutrient absorption and utilization,photosynthetic characteristics,fruit yield and quality of blueberry.The main conclusions were as follows:1.Compared with the control check(CK),water-fertilizer coupling effectively reduced soil pH and increased soil organic matter,total nitrogen,total phosphorus,total potassium and available nitrogen,available phosphorus and available potassium.The contents of soil organic matter,total nitrogen,total phosphorus,total potassium and available nitrogen,available phosphorus and available potassium were higher in high(F1)than those in medium(F2)and low(F3).In general,the order of the effects on soil organic matter from big to small was fertilizer coupling> fertilization> irrigation,and on nutrient indicators was fertility> water and fertilizer coupling> irrigation.2.Compared with the control check(CK),total nitrogen,total phosphorus and total potassium contents of shoots and leaves were effectively increased by water and fertilizer coupling.The content of total nitrogen in shoots was higher than that in high fertilizers(F1)and low fertilizers(F3),the contents of total phosphorus and total potassium in branches were the highest at high level(F1)The contents of total phosphorus and total potassium were higher than that of high fertilizer(F1)and low fertilizer(F3).Effects of fertilization,irrigation,water and fertilizer coupling on the total nitrogen content of shoots from large to small was water and fertilizer coupling> fertilization> irrigating;effect on total phosphorus,total potassium and total nitrogen,phosphorus and potassium in shoots was fertilizers> irrigation> water and fertilizer coupling.3.When the external conditions were stale,photosynthetic rate(Pn),the stomatal conductance(Gs)and the transpiration rate(Tr)of the blueberries were increased with the increase of the light intensity(PAR),and gradually decreased after reaching the light saturation point.The photosynthetic rate of the plant was stronger than that of the medium(F2)and the low fertilizer(F3).With the increase of the level of water and fertilizer,the photosynthesis of the plant was gradually enhanced,and the water and light coupling treatment was better than the control.4.Compared with the control check(CK),the contents of chlorophyll a,chlorophyll b,total chlorophyll,SOD,soluble sugar and soluble protein in blueberry leaves were significantly increased,and the content of MDA was decreased.When the fertilizaing amount were equal,with the increase of irrigation amount,the chlorophyll content,soluble sugar content and soluble protein content increased at first and then decreased.When the irrigation amount were equal,basically,with the increase of fertilization amount,chlorophyll content increased at first and then decreased.Under W1 and W2 irrigation levels.,soluble protein was the highest in F3 fertilization level,Under W3 and W4 irrigation levels,soluble protein was the highest in F2 fertilization level.5.Compared with the control check(CK),growth of shoots under medium treatment(F2)was significantly better than that of high(F1)and low(F3)treatments.The high or low fertilization levels had inhibited effects.In the same fertilization level.The number,branch diameter and length of shoots increased at first then declined with the increase of irrigation amount.The water and fertilizer coupling had no significant effects on the vertical and horizontal diameter of blueberry buds,but significantly,the number of flower buds was improved,and the medium and high water treatment was better than the low water treatment.The sufficient water content was more favorable for the growth of the shoots than water deficit.F2W2 and F2W3 were the best shoot growth coupling level.As a single factor,Fertilization and irrigation had no significant effects on the growth of shoots in the first year.But had significant effects on the number and the length of shoots in the following year.The coupling of water and fertilizer had a significant effect on the number of shoots in the first year,and a very significant effect on the number and the length of shoots in the second year.These three factors had no significant effects on the brunch diameter of shoots,but flower bud amount.6.Compared with the control check(CK),water-fertilizer coupling had no significant effects on longitudinal and traverse diameters of fruits in the first year but significantly increased longitudinal diameter in the second year.Low treatment(F3)was slightly higher than that of high fertilizer(F1)and medium fertilizer(F2),the optimum coupling level was F2W2,Water-fertilizer coupling significantly improved the yield per plant of blueberry,and medium fertilizer(F2)treatment was better than that of high(F1)and low(F3).when irrigation amounts were equal.When the amounts of fertilizer were equal,the yield per plant was higher than that of high(F1)and low(F3).The increase of irrigation amount increased first and then decreased.The coupling of water and fertilizer significantly increased the content of anthocyanin,soluble sugar,total phenol and flavonoids in blueberry fruits,but had no significant effects on soluble solids.The effects of water and fertilizer on the interaction of soluble sugar,soluble protein and titratable acid,water and fertilizer,fertilization and irrigation were as follows: water-fertilizer coupling > water effect> fertilizer,and in the case of fruit anthocyanins,flavonoids and total phenol,water-fertilizer coupling > fertilization> irrigation.