Research On Characteristics Of Evaporation And Transpiration Of Apple Trees Under Water Storage Pit Irrigation

Water storage pit irrigation is a kind of to solve the northern drought and soil erosion model of three-dimensional deep irrigation. The biggest feature is the change of soil infiltration interface, so that the surface soil moisture content is low, the deep water rate is high, with fruit years of woody plant root growth distribution, so that water is more direct and more effective absorbed by vegetation, increase water use efficiency, conservation of water resources, water and soil conservation. This paper research in Pomology Institute,Shanxi Academy of Agricultual Sciences in TaiGu county apple orchard, conducts the research to the evaporation transpiration of apple trees under water storage pit irrigation, adopt the method of combining field experiment and theoretical analysis, the main results are as follows:1. The research on transpiration of apple leaves under water storage pit irrigation.(1) the tree leaf transpiration daily variation study found that different pit deep under the condition of the apple tree leaf transpiration rate were unimodal curve, the60cm deep pit of average daily transpiration rate is smaller than40cm deep pit. At the same time, the study found the tree leaf transpiration rate and its influencing factors is roughly single-peak curve. Various factors influence the size of the transpiration rate of photosynthetic available radiation, intercellular CO2concentration, stomatal conductance, leaf temperature, CO2concentration in the air, the air temperature and vapor pressure deficit based on leaf temperature, vapor pressure deficit based on air temperature, air relative humidity.For apple tree leaf transpiration diurnal variation, the study found leaf transpiration rate under the condition of water storage pit irrigation regularity for July> September>August. During the month7～9, daily change patterns of leaf of roughly the same, is a single peak curve, the less obvious midday depression in a day, reached the peak at about12:00～14:00.(2) The different irrigation methods comparison, found that the ground irrigation peak time earlier two hours than the water storage pit deep60cm, the peak value of the order as follows:the surface irrigation>the water storage pit deep40cm>the water storage pit deep60cm. Overall, the size of the average daily transpiration rate of the three order as:the water storage pit deep60cm<the water storage pit deep40cm<the surface irrigation. Leaf water use efficiency (WUE) among them, found that two kinds of irrigation methods of leaf water use efficiency, all at about8:00in the morning at the upper end of the day in WUE with recursive rule are:August>September>July; Water storage pit irrigation in7～9months of leaf water use efficiency significantly greater than ordinary surface irrigation.2. The variation of apple tree sap flow under water storage pit irrigation(1) under different weather conditions for different water storage pit depth of the tree trunks sap flow study, regardless of sunny or rainy the changing rule of the two kinds of deep pit is roughly same, but start time and peak was different. Rainy days sap flow significantly lower than the sunny day. Under the condition of sunshine, water storage pit irrigation apple daily variation of flow show "几"word, lunch break phenomenon was not obvious. Under the condition of a rainy day, the type of sap flow was multi-peak. The water storage pit depth60cm, trunk liquid flow bigger than40cm. Months contrast found that July stem flow range is the largest, the second respectively in June, August and September.(2)Under the condition of water storage pit irrigation the apple tree, flow rate and meteorological factors relationship study found that affect the pit depth apple tree trunk flow rate of meteorological factors are the average air temperature, relative humidity and the actual sunshine time, respectively to exponential relationship, negative linear and quadratic polynomial relations, and the actual sunshine time was the greatest influence factors, and the wind speed was not the main influence factors.(3) the apple tree flow rate under different irrigation methods comparison, Jound that in June to September, as a whole, the trunk of common ground irrigation sap flow is larger than under the condition of water storage pit irrigation, especially at the end of June early July, is even more significant difference, after the difference is not big, but the difference is bigger to the end of September.3. Research on apple tree transpiration quantity computing under the condition of water storage pit irrigationUsing the sap flow and micro-lysimeters, FAO56recommend dual crop coefficient method and the calculation of water balance under the condition of water storage pit irrigation evapotranspiration of the apple tree, found that the three results had good consistency. Showing use the sap flow and micro-lysimeters the condition of water storage pit irrigation evapotranspiration measurement had certain feasibility of apple trees.