Study on N, P, and K Uptake and Fertilization of Young‘107‘Poplar Clone with Drip Irrigation Characteristics of dry matter, accumulation and distribution of N, P and K of superhighyield summer maize Characteristics of dry matter and nutrients accumulation and transformation of super-high yield spring maize Effect of waterlogging on nutrient uptake and transport of summer maize Characteristics of nitrogen, phosphorus and potassium uptake and accumulation of potato in Ningxia