Stepwise Precision Fertilization To Quantify Nutrient Accumulation And Partitioning In Double-season Sweet Potato...

Double-season fresh sweet potato production often experiences a mismatch between soil nutrient supply and crop demand, leading to suboptimal yield and inefficient resource use. Traditional fertilization often relies on basal applications that fail to meet the crop's dynamic requirements under distinct spring and autumn meteorological conditions. This article presents a comprehensive protocol for a stepwise precision fertilization strategy that synchronizes nitrogen, phosphorus, and potassium inputs with critical phenological nodes. The method partitions total nutrient inputs into five distinct application events corresponding to specific growth stages: seedling establishment, vine expansion, tuber initiation, rapid bulking, and maturation. The protocol further describes a rigorous destructive sampling regime to dissect whole-plant nutrient partitioning. By employing logistic nonlinear regression models, researchers can quantify the maximum accumulation capacity, duration of the rapid uptake phase, and inflection points of nutrient uptake. This approach enables precise identification of critical absorption windows and evaluation of apparent nutrient balances. The application of this protocol facilitates the optimization of fertilization regimes, enhancing both storage root yield and commercial quality while reducing the risks associated with nutrient deficits or surpluses in intensive double-cropping systems.