摘要
在不同供氮水平条件下,供试的48个桑树品种叶、条、根中氮、磷分布、营养效率及所施氮肥的利用率差异表明,施氮处理比无氮处理叶、条、根中全氮含量及其累积量极显著增加,全磷含量极显著降低;磷素累积量除叶片无显著差异外,根和枝条中均极显著增加。从整个植株氮、磷浓度分布看,全氮含量为叶片>根>枝条;全磷含量为根≈叶>枝条。从整个植株根、枝、叶氮、磷累积情况看,氮素累积量及无氮处理的磷素累积量为叶片>根>枝条;施氮处理,根、枝条、叶片中磷素累积量相差不大。施氮处理比无氮处理氮、磷运转效率及氮素经济利用效率均极显著降低,而磷素经济利用效率极显著提高。不同桑树品种氮、磷吸收累积量、营养效率、氮肥利用率差异很大。只有氮肥利用率高且植株吸收的肥料氮大部分分配在叶片中、而仅极少部分用于根和枝条建造的桑树品种,才能够更经济有效地利用氮素。
Under different N conditions the distribution and nutritional efficiency of N, P and the N recovery of mulberry cultivars were significantly different At higher N rate the concentration of N and accumulated N was increased significantly, the concentration of P was decreased significantly, and the accumulated P was increased in roots and shoots except leaves The concentration of N in different organs decreased in the order: leaves>roots>shoots, and the concentration of P∶leaves≈roots>shoots The accumulated N? P in the whole plant were accumulated N and accumulated P (CK): leaves>roots>shoots,but accumulated P (at higher nitrogen rate) in different organs was not significantly different Under higher N conditions the mobilization indexes of N and P decreased significantly, the Nuse efficiency decreased and the Puse efficiency increased significantly The differences of N recovery of supplied N and nutritional efficiency of N and P in mulberry cultivars were considerable All these characteristics may be used as important indices for identifying and selecting high efficient varieties or genotypes
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2003年第1期106-111,共6页
Journal of Plant Nutrition and Fertilizers
关键词
桑树
氮
磷
分布
营养效率
品种差异
氮肥利用率
mulberry cultivars
nitrogen
phosphorus
nutritional efficiency
nitrogen recovery
