|
The article is for the premise of water-saving、excellent quality、more production and high-efficiency, for the goal of developing and promoting the use of agricultural water-saving technologies, about the study of pear-jujube tree compensation technique for water-regulated. Tests are carried on in the Ministry of Education Key Experimental Station of arid agricultural laboratory of the Northwest A&F University in Yangling Shaanxi province. Through test analysis the law of water Consumption and environmental factors that affect water consumption and its correlate degree. At the same time, the changes of Eco-physiological indicators and the Compensation effect under different water treatment on pear-jujube trees had been proved. through the quality and production of the fruit, then develop a set of high-quality, more production, and high efficiency irrigation regulate program. The program can provide us some Theoretical basis for development of the water regulation and control compensation technology. The main results of the research are as follows:(1) For the different water treatment, the vertical distribution of water is not very different. The changes of the moisture mainly concentrated in the 20-80cm depth; water Consumption during all growth stage is concentrated on April to October for Pear-jujube tree, which is accounted for more than80% of year’s; Moisture content and Water-regulated treatment was positive correlation in the plan moist layer.(2) The study of water consumption feature of pear-jujube indicate: except the winter dormant period, to the normal water-supplying, the remaining phase of the average daily volume of evaporation is about 0.85mm, daytime transpiration water consumption at around 2.3mm; but to the water-regulated, the evaporation and transpiration are less than the normal water-supply. To the transpiration law of normal water-supply: from the 8:00, the transpiration rate began to rise, continued until 13:00 about reached its peak and then begin to decline, by 20:00 at night and then maintained the steady state, changes in the overall day was a single peak curve. At sunny, for water-regulated treatment of pear-jujube tree, the trend of its change is very similar to normal water-supply, but the peak of transpiration rate is smaller than normal, and it occurs about one hour later than the normal water-supplying. At Cloudy, because the transpiration is litter, the trend of change for each treatment is similar to the normal’s. (3) For environmental factors which affect the transpiration, Finally determine the order of the related factors as follows: at sunny, to normal water supply: The maximum day temperature>Soil moisture>Day average temperature>Net solar radiation intensity; to water-regulated: Soil moisture>The maximum day temperature>Net solar radiation intensity >Day average temperature; at cloudy, at different water treatment, the correlation of the affect between different factors is not very different, temperature is mainly affected, followed by water.(4) Through the study of the pear–jujube tree physiological indicators of trends, we can find that each physiological indicators has a high sensitivity on water, when moisture stress occurred, consumption and absorption in inner plant will be regulated; there are obvious compensation effect in these respects such as:transpiration rate(flow rate), photosynthetic rate, leaf water potential, jujube hanging and branches, moreover, the Compensation capacity of each indicator at a certain range of water stress is positively correlated to the degree of water stress, which can meet to the goal of water-saving、high-efficiency.(5) At different stage, different water treatment have different affect on the quality of the pear-jujube, water-regulated in the period of fruit enlargement have adverse effects on much morphological indicators, and reach significant level (P<0.05), which indicate water-regulated is not implemented in this period. Water-regulated in the period of fruit maturity can improve the fruit hardness,colorist rate,and the content of vitamin C,soluble solids,soluble sugar and so on (P<0.05). It can also make the purpose "water-regulated ripening, long-term preservation”achievable. Water- regulated on other stages has certain impacts which between normal water supply during all growth stages and the ripe period. All these statement proved that water-regulated in the period of fruit maturity can not only achieve the purpose of saving water but also to achieve the purpose of "using the water to regulating the quality, Regulating water to speed up ripening, improving effectiveness".(6) We can finally get the best irrigation program of pear-jujube tree through the analysis of the quality production and economic benefits. The irrigation program is as follows: carried out with mild to moderate combination of regulating water in winter dormancy period, exhibition period of leaf bud and fruit maturity period can not only saving more water but also arouse the compensation growth potential of the pear-jujube tree, and to create more conditions for the purpose of water-saving, more production, high efficient.
|