Research On Characteristics And Model Of Apple Tree Leaf Under Water Storage Pit Irrigation

Along with the increasing of water shortage, water pollution and otherproblems, the agricultural economy development of our country has beenaffected. Traditional orchard irrigation in China can not make full use of waterresources, and caused serious waste of water. The method called water storagepit irrigation was put forward by Professor Xihuan Sun at1998. It has theadvantages of saving water, conserving water and soil, and drought resistance.This method is a new type orchard irrigation mode combining the characteristicsof the root distribution which mainly for the northern arid and semi-arid region.In this paper, studied the apple tree leaf transpiration characteristics under thecondition of water storage pit irrigation through field experiment in Shanxi FruitInstitute and combined with the research methods of theoretical analysis. Thefollowing is the main research conclusion:1. The research of apple tree leaf transpiration characteristics under thecondition of water storage pit irrigation.(1) Through the studies of daily variation of apple tree leaf transpirationunder different processing conditions, found that the daily change rule were allshowed a trend of unimodal curve. Leaf transpiration rate is low in the morning, and then gradually increased with time. Reached its peak in the middle of theday, then gradually reduced. Leaf transpiration rate under the condition of waterstorage pit irrigation in every moment of the day most are higher than that underthe condition of surface irrigation; Leaf transpiration rate of60cm deep pit ofwater storage pit irrigation blade before11:00a.m. lower than40cm deep pit,while after11:00instead, but the daily average transpiration rate is higher than40cm deep pit; Leaves of60cm water storage pit irrigation irrigation the leaftranspiration rate in every moment of the day is obvious higher than that of nonfull irrigation.(2) Leaf transpiration rate under different processing conditions of monthlychange trend is consistent. On May4kinds of processing of leaf transpirationrate is low, as the change of time was accelerated, on August to the highest, thendecreased. Leaf transpiration rate of water storage pit irrigation60cm deep pitfull irrigation is higher than the other three, and leaf transpiration rate of60cmdeep pit of water storage pit irrigation of non full irrigation is the lowest of4kinds of processing.(3) Leaf transpiration rate influence factors including the internal factors(Cond, Ci, VpdL) and external environmental factors (Tair, RH, VpdA, PAR),through the correlation analysis of impact factors with different processingconditions, found that: from May to October, the influence of various factors onapple tree leaf transpiration rate each are not identical. The diurnal variation ofthe apple tree leaf transpiration rate and that not only is influenced by irrigation, but also affected by the comprehensive internal factor and environmental factorin the meantime.2. The research of leaf water use efficiency under the condition of waterstorage pit irrigation.(1) Through the studies of daily variation of apple tree leaf water useefficiency under different processing conditions, found that the daily change rulewere all presented a similar change trend in every month.7:00-9:00in themorning to reach the maximum of a day, and as the change of time decreases.Every moment of the day, the leaf water use efficiency under the condition ofwater storage pit irrigation60cm deep pit of non full irrigation almost thebiggest, and the leaf water use efficiency under the condition of surface fullirrigation and40cm deep pit full irrigation are all smaller.(2) Leaf water use efficiency monthly change rule under differentprocessing conditions is consistent. On May, the leaf water use efficiency wereall higher, June and July is low, and then increased in August and September,and reduced in October. From May to October, the size of leaf water useefficiency of four kinds processing were: non full irrigation of60cm pit depthwater storage pit irrigation, full irrigation of60cm pit depth water storage pitirrigation, full irrigation of surface irrigation, full irrigation of40cm pit depthwater storage pit irrigation.(3) Through the research of leaf water use efficiency under differentprocessing conditions impact factors found that from May to October the influence degree of various factors on apple tree leaf water use efficiency isdifferent. But the main influence factors were intercellular CO2concentration,air relative humidity, air and leaf temperature.3. The BP neural network model of leaf transpiration rate under thecondition of water storage pit irrigation.In this paper, established a three layer BP neural network model throughinternal environmental factors predicting transpiration rate based on MATLABof the transpiration rate of apple trees under the condition of water storage pitirrigation. And the model is verified. Results showed that the established BPartificial neural network model can be better applied to predicting apple tree leaftranspiration rate under the condition of the water storage pit irrigation.