The Effect Of Fertilizer On Olive Growth And Photosynthesis Characteristics Under The Drip Irrigation

In recent years,the area of olive has been increasing year by year in China.However,there are many problems in the process of production,such as varieties mixed and lagging cultivation technology.As far as fertilization technology is concerned,whether the amount of fertilization is appropriate,otherwise there is currently very little research and there is a lack of scientific and reasonable fertilization data.The phenomenon of arbitrary fertilization on the basis of subjective experience in production is predominant and often causes problems such as falling of the olive tree,premature failure of the tree,decrease on yield,and deterioration of quality.Research on fertilization technology has become an important issue in the current olive production.Therefore,research on the effect of fertilizer on olive growth and determining the optimum amount of fertilizer has important reality significance for the high quality and high yield of olive.In this study,four year-old Koroneiki and Coratina two olive varieties were used as materials to set up seven different fertilization treatments{CK（N:0、P₂O₅:0、K₂O:0）、T1（N:12、P₂O₅:4.6、K₂O:7.2）、T2（N:24、P₂O₅:9.2、K₂O:14.4）、T3（N:36、P₂O₅:13.8、K₂O:21.6）、T4（N:48、P₂O₅:18.4、K₂O:28.8）、T5（N:60、P₂O₅:20.3、K₂O:36）and T6（N:72、P₂O₅:27.6、K₂O:43.2）（unit:g/plant）},fertilization by drip irrigation,to study its influence on the growth and physiological characteristics of olives could come to the following conclusions:（1）Effects of different fertilizer levels on nutrient elements in olive leaves.In a certain range of fertilization amount（T1,T2,T3,and T4）,the total N content in the leaf of the two olive cultivars of Koroneiki and Coratina increased with the increase of fertilization amount,and the higher fertilization amount（T5,T6）,the total N content in leaves did not have the trend of increase or decrease.Overall,each fertilization treatment significantly increased the total P content in the leaves compared with CK.Except for a few time periods（Koroneiki in July and Coratina in June）,there was no significant difference among the fertilization treatments.The total K contents in leaves of Koroneiki and Coratina increased with the increase of the amount of fertilizer under the T1,T2,and T3treatments.When the amount of fertilizer was continuously increased,not only did not the total K content in the leaves increase,but also decreased.The trend of change in total N,P,and K content in leaves of Koroneiki and Coratina during different times（from June to November）were concluded:N showed a trend of increasing first and then decreasing,and the total N content of leaves of both varieties was that is the lowest in November.P showed an increase from June to July,a decrease from July to September,a trend of stabilization from September to October,a slight increase from October to November.K showed a trend of entire decrease.（2）Effects of different fertilizer levels on physiological characteristics of olive.Overall,T1,T2,and T3 could significantly increase the content of chlorophyll a and chlorophyll b in leaves of Koroneiki and Coratina.T4 had no significant effect on the contents of chlorophyll a and chlorophyll b in leaves of Koroneiki and Coratina.T1,T2,T3,and T4could significantly increase the leaf carotenoid content of Koroneiki and Coratina.T5 and T6 would reduce the content of chlorophyll a,chlorophyll b,and carotenoids in Koroneiki and Coratina.The fertilization amount of T1 and T2 had the most significant effect on the content of chlorophyll a,chlorophyll b and carotenoids.Under the conditions of this experiment,the chlorophyll a and chlorophyll b contents of Koroneiki and Coratina showed an upward trend with the progress of time from June to July,and from July to November showed a decreasing trend.The content of carotenoids in the two varieties had no significant change trend from time to time from June to October.From October to November,the carotenoid content showed an upward trend.The carotenoid content of both varieties was higher in mid-November.TThe Pr,Tr,and Gs of the Koroneiki are higher at T1 and T2 and lower at T3,T4,T5,and T6.In Coratina,Pn and Tr are higher at T1 and T2and lower at T3,T4,T5 and T6.The Coratina Gs decreased with T1,T2,T3,T4,T5,and T6 treatments.T1,T2,T3,T4,T5,and T6 could significantly increase the Intercellular CO2 concentration（Ci）of Koroneiki,and also significantly improved Coratina,Ci in August and November.It had little influence on Ci in the other months of Coratina.The water use efficiency of Koroneik and Coratina have no obvious regularity.The net photosynthetic rate（Pn）between Koroneiki and Coratina did not change significantly over time from June to October.From October to November,it showed a decreasing trend.The overall Pn of two varieties was the lowest in mid-November.From June to November,the transpiration rates（Tr）of Koroneiki and Coratina increased gradually with time,and the stomatal conductance（Gs）gradually decreased with the developing of time;The Ci did not change significantly with time,and Coratina Ci was higher in November.（3）The effect of different fertilizer levels on olive growth.The increase in plant height and shoot growth of Koroneik and Coratina was the largest under T3 conditions.The number of branches of the Koroneik was the highest under the conditions of T4 and T5,and the number of branches of the Coratina was the highest under the condition of the T3,T1 and T2 could significantly promote 4-year-old Koroneik and Coratina to form fruit.In summary,the different fertilization treatments under drip irrigation condition affected the growth and physiological characteristics of Koroneik and Coratina olives.In this experiment,the effect of different fertilizers on olives under drip irrigation was studied,combined with the actual production.It was determined that suitable fertilization range of4 year-old Koroneik and Coratina were T2-T3.It provides theoretical basis and technical support for olive cultivation,management and fertilization technology.