Effect Of Fertigation On The Growth, Yield And Quality Of Chinese Jujube In Loess Hilly Region

In this study,4-year-old jujube trees were chosen as experimental material，and theeffect of solid fertilizer and fertigation on the growth, yield and quality of jujube in loesshilly region was investigated. N (nitrogen), P (phosphorus), K (potassium) fertilizer andthree factor D-saturation optimal design was for the application of solid fertilizer，while N(nitrogen), P(phosphoric acid), K(potassium) fertilizer and water and four factors quadraticregression rotation combination design was for fertigation. The results showed that:1. Both of solid fertilizer and fertigation promoted the growth of jujube. Under solidfertilizer condition, application of nitrogen increased CCI value by17.06%compared withCK, it reached highest point of27.44in8thaugust. Application of combined nitrogenphosphorus and potassium (N1P3K3) increased the length of new branch by23.5%than CK,and the daily increasing amount of jujube size in N3P1K3treatment was maximum. Thehighest fruit setting rate and yield of jujube were observed in N3P1K3, which was17.06%and16094.5kg/hm2, respectively. Application of two kind of fertilizer improved fertilizeragronomic efficiency, and excessive fertilizer reduced it. The effect of N, P, K fertilizer onthe yield of jujube was observed in the sequence of K (positive effect)> N (positiveeffect)> P (positive effect).Under fertigation condition, the highest CCI value and new branch length wasappeared in N4P4K4W4treatment, which was29.11and202.42mm, respectively. The dailyincreasing amount of jujube size in N3P3K3W3treatment was maximum. The highest settingrate and yield of jujube were observed in N3P3K5W3treatment. The increasing irrigationamount improved fertilizer agronomic efficiency, Increased in one of nitrogen, phosphorusand potassium fertilizer factors help to improve the agronomic efficiency of the other twofactors. The effect of N, P, K fertilizer and water on the yield of jujube was observed in thesequence of N (negative effect)> K (positive effect)> P (positive effect)> water (positiveeffect).2. Solid fertilizer and fertigation had an influence in jujube quality. Under solid fertilizer condition, total sugar content was increased by20.38%in N2K2treatment whencompared with CK, the maximum reducing sugar content was observed in N1P3K3, whichwas increased by25.16%compared with CK. Fertilizer increased the sugar-acid ratio in asignificant level, especially the application of nitrogen, phosphorus and potassium. Thetreatment of N3P1K3improved the total flavonoids content significantly, application ofsinger P, combined N and P, N and K did not influence the total flavonoids content. With theexception of P2K2, the remained treatment improved vitamin C content of jujube. Nitrogenhad significantly increased the soluble solid content of jujube, all fertilizer treatment hadincreased the fruit size, and P2K2was most remarkable. Under solid fertilizer condition, theeffect of N, P, K fertilizer on the quality of jujube was observed in the sequence of N(positive effect)> N (positive effect)> P (positive effect).Under fertigation condition, the highest total sugar content was appeared in N3P3K3W5treatment, increasing irrigation amount help to improve total sugar content. The sugar-acidratio ranged from8.99(N3P3K3W5treatment) to23.47(N3P3K3W3treatment). With highlevel of fertilizer and water, the N4P4K4W4treatment improved the total flavonoids content.In N5P3K3W3treatment, the vitamin C content was maximum, the ratio of any two factorshad an influence in vitamin C content. Increasing K fertilizer amount help to improve thesoluble solid content, while P, K and water did not affected it. Under fertigation condition,the effect of N, P, K fertilizer and water on the quality of jujube was observed in thesequence of P (negative effect)> K (negative effect)> Water(negative effect)> N (positiveeffect).3. The frequency analysis method was used to evaluate the impact of fertilization onthe yield and quality of jujube. The results showed that: under solid fertilizer condition,when the expected yield and quality score was11500~18700kg/hm2and over85, theoptimal fertilizer rate is nitrogen (N)145.06~223.06kg/hm2，phosphorus （P2O5）87.95~119.65kg/hm2，potassium（K2O）82.92~105.74kg/hm2。Under fertigation condition, when the excepted yield was14500~21000kg/hm2andquality score was over90, the optimal fertilizer rate is nitrogen (N)181.70~202.30kg/hm2,phosphorus(H3PO4)272.96~292.52kg/hm2, and potassium (K2O)112.19~122.45kg/hm2,water (H20)661.01~730.94m3/hm2。...