Effects of fertilization on growth and seasonal dynamic of leaf nutrients of close planting pear-jujube trees Effects of the different organic fertilizers on growth,photosynthetic characteristics and quality of Pear-jujube of in the Loess Plateau Rational Indicators for Irrigation Scheduling of Pear-jujube Based on Microchanges of Stem Diameter Rational Indicators for Irrigation Scheduling of Pear-jujube Based on Microchanges of Stem Diameter