Jiangsu Provincial Key Lab of Solid Organic Waste Utilization/Jiangsu Collaborative Innovation Center of Solid Organic Wastes/Educational Ministry Engineering Center of Resource-saving Fertilizers Nanjing Agricultural University Nanjing 210095 P.R.China;
Institute of Fruit and Floriculture Gansu Academy of Agricultural Sciences Lanzhou 730070 P.R.China;
fertilization time; N distribution; N storage; N remobilization; Pear(Pyrus bretschneideri Rehd cv.Huangguan);