Effect Of Irrigation And Nitrogen On Water Transportation And Water Consumption Of Fruit Seedling

With increasing shortage of water resources in the whole earth and water quality deterioration constantly, we can make use of less and less water resources year by year. The crop physiology water-saving is become more and more emphasized with the research by more multi-disciplinary, such as Agriculture Soil and Water Engineering, Plant Physiology, Agriculture Ecology, Ecosystem Hydrology and so on. In recent years,the grow area and water consumption of fruit seedling are continuously enlarge with more economic benefits which have brought to farmer. At the same time, dry and water shortage in northern region of china also seriously influences the forestation survival rate and the growth of the fruit tree. The orchard breeding cultivation and water benefit had already widespread been subjected to the value. So it is important to adopt a scientific management measure to the orchard use water. Accurately understanding hydraulic conductivity (shoot, root and leaf), transpiration consume water mechanism of seedling, not only are favorable for cultivating orchard seedling, reasonable irrigation, apply fertilizer the system, raise the fruit tree survival rate, sound seedling and water-saving, but also can further study hydraulic conductivity, water consume character of economic seedling, the influence mechanism of water and nitrogen, rich water-saving theory.This article take one-year-old peach, pear and apple seedling as pot experiment material, the experiment was carried in the rainproof shelter of Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education, Northwest A & F University. We laid emphases on the effect of hydraulic conductivity (shoot, root and leaf) ,sap flow, photosynthesis characteristic, water consume character of fruit seedling under different water and nitrogen. Water was supplied by three levels: sufficient irrigation, milder deficiency irrigation and serious deficiency irrigation. Three nitrogen levels: high, moderate and none nitrogen with pure nitrogen per kg soil 0.3g, 0.15g, 0g respectively. The apple seedling was only carried on the different humidity treatment. We got some conclusions were as follows:Compare three kinds of fruit seedlings, the peach seedling grow faster under the same treatment. The fruit seedling has a sparse leaf, comparatively large leaf area and leaf side even and smooth under the sufficient soil moisture. On the contrary there is a leafy, dense leaf and comparatively small leaf area and leaf side uneven and wrinkly. The effect of soil water content and nitrogen on total dry matter of fruit seedling achieved the remarkable level. With the increase of soil water content and nitrogen there is an increase of dry matter.In the growth process of the fruit tree seedling, the change of hydraulic conductivity was on a single peak curve or dual peak curve under temperature effect. The leaf area and leaf hydraulic conductivity increase with the increase of soil water content. Nitrogen fertilizer has a remarkable effect on leaf hydraulic conductivity of peach and pear seedling. The leaf area and leaf hydraulic conductivity increase with the increase of nitrogen.Three kinds of fruit seedlings have the same feature, the hydraulic conductivity increase with the increase of soil water content. Under the same water and nitrogen treatment, the magnitude of root hydraulic conductivity for the 3 fruit seedling was: peach>pear>apple. The root and shoot hydraulic conductivity increase with the increase of nitrogen, the root has a maximum hydraulic conductivity under N3 treatments and reduce one by one under N2,N1 treatment.There was a positive correlation between root hydraulic conductivity and root diameter. Diurnal sap flow velocity change of Pear seedling has a daily periodicity and continuous diurnal variations under different water treatment. Sap flow dynamical diurnal change of peach seedling present single peak curve under normal growth status. The sap flow velocity increase at 8:00 and present typical single peak curve with the increase of temperature and transpiration intensity and decrease of air relative humidity. The maximum peak of sap folw velocity appears at pre and post 12:30. The maximum peak of sap flow velocity reached about 9.5g/h and 11g/h respectively under W3 and W1. The decline speed was obviously decreased under W1 and has a trend of ahead of time. Under the same nitrogen treatment, sap flow velocity increase with the increase of soil water content. The effect of water on sap flow more obvious under N3 treatment. Sap flow velocity changed obviously between different nitrogen treatments under sufficient water supply. The maximum peak of sap flow velocity reached about 24g/h, 17g/h and 12g/h respectively under N3 and N2 and N1.