Effects of soil water and nitrogen nutrition on growth and hydraulic conductivity of fruit tree seedling

In order to understand the mechanism of hydraulic conductivity, water transmission and the effect of water and nitrogen on varieties of fruit trees，the effects of different soil water and nitrogen treatments on growth and hydraulic conductivity of fruit tree seedlings were conducted by barrel experiments. Peach (Prunus persica (L.) Batsch), pear（Pyrus spp．）and apple（M. pumila Mill）seedlings were used as experimental materials. The values of hydraulic conductivity of fruit tree seedlings were measured with high pressure flow meter (HPFM, US Dynamax Company). The results showed that there were significantly differences on growth of fruit tree seedlings under different water and nitrogen treatments. Soil moisture had significant effects on root and crown hydraulic conductivity. Hydraulic conductivity decreased with the decreasing of soil moisture. Soil droughts limited the growth and biomass accumulation of the roots of the fruit tree seedlings, so the values of hydraulic conductivity of root and crown were decreased. Nitrogen also had significant effects on the hydraulic conductivity of fruit tree seedlings. Nitrogen fertilizer application could increase the hydraulic conductivity of root and crown of fruit tree seedlings. There are liner correlations between hydraulic conductivity and root diameter of fruit tree seedlings, height and root diameter of fruit tree seedlings under experimental conditions.