Effects Of Different Irrigation Modes And Bark Cover On Water Eco-physiological Characteristics Of Gingko Biloba

This research adopts the way which the field test and the pot experiment unify mutually, studied the tree to spring irrigation, the flooding irrigation and the infiltrating irrigation three different irrigation way,as well as commonly used bark cover saving water measure in the north urban regarding the gingko water regime influence.Through determination gingko water relations factors and so on soil water content, soil water potential, volume water content and leaf water potential,leaf water content, relative conductivity, chlorophyll content, photosynthesis speed, transpiration rate, cond, have analyzed the different irrigation way to the gingko water related physiology influence, the result have provided the botanical garden tree saving water way and tree type's choice the theory basis and the research methodfor our country north part. The main related findings are as follows:1. The field test discovery, the spring irrigation and the infiltrating irrigation way soil moisture content is lower than the flooding irrigation, But along with time expand, difference between different treatment reduce.The infiltrating irrigation way soil water potential is higher than the spring irrigation and the flooding irrigation(30-40cm level); In same irrigates quantity, the infiltrating irrigation way leaf water potential is the highest, next is the spring irrigation and the flooding irrigation. Infiltrating irrigation and spring irrigation, flooding irrigation existence remarkable difference; Irrigates the quantity infiltrating irrigation is only other way in 2/3 situation, the infiltrating irrigation way leaf water potential value is lower than the spring irrigation way, the flooding irringation is the lastt. The infiltrating irrigation way leaf water content is the highest, spring irrigation is the next, flooding irrigation is the last, remarkable difference exists. The chlorophyll content's value order is the infiltrating irrigation the flooding irrigation> the spring irrigation, the leaf relative conductivity value order is flooding irrigation> the spring irrigation>the infiltrating irrigation. Through the variance analysis discovery, each irrigation way is not remarkable to gingko's chlorophyll content and injury rate affects.2. Pot experiment discovery, with same irrigates quantity, the flooding irrigation way the 0-20cm level the soil volume water content to be highest, but the 20-30cm level soil volume water content infiltrating irrigation is highest; The infiltrating irrigation way's leaf water potential is the highest, the spring irrigation is the next, the flooding irrigation is the last. Transpiration rate and photosynthesis rate value order is flooding irrigation>spring irrigation> infiltrating irrigation. In September:The spring irrigation and the infiltrating irrigation way's soil volume moisture content obviously is higher than the flooding irrigation in the earlier period, but the later period has the situation which is lower than the flooding irrigation. Leaf water poteantial value order is spring irrigation> flooding irrigation> infiltrating irrigation. Transpiration rate and photosynthesis rate value order is flooding irrigation> infiltrating irrigation> spring irrigation. The cond change tendency is consistent with the photosynthesis speed. The spring irrigation and the infiltrating irrigation processing relative conductivity is higher than the flooding irrigation, but the spring irrigation processing chlorophyll content compared to flooding irrigation lower, this result is inconsistent with the field test, thought that with the pot experiment in the vessel limit, as well as cannot the prompt use moisture content toward the barrel head dropout.3. Regardless in the field test or in the pot experiment, the bark cover displays the good soil holding water function. Mulch treatment's leaf water content and the transpiration rate are higher than the bark cover, but the leaf water potential is lower than the bark cover.In September the pot experiment bark mulch treatment displays compared to mulch treatment the higher transpiration rate and the photosynthesis rate, and discovers bark cover treatment's green time is longer than mulch treatmen. In the field test and the pot experiment discovered that the bark cover treatment the chlorophyll content is higher than mulch treatment, and the leaf injury rate is lower than the mulch treatment. Compares with the mulch treatment cover.4.The spring irrigation and the infiltrating irrigation have the saving water effect, the infiltrating irrigation saving water effect is better. The bark cover has guarantees the water the function, applies the infiltrating irrigation and the spring irrigation effect in the green space tree is good.