氮钾互作对甘薯源库平衡关系影响的模型构建及诊断研究

协调甘薯源库关系是甘薯高产的前提，氮钾合理配施是解决甘薯源库平衡关系的关键，探明氮、钾营养及其交互作用对甘薯源库平衡关系的影响对于合理施用肥料、提高甘薯生产水平具有重要意义。本项目拟从氮钾互作对甘薯源库平衡关系影响的关键科学问题出发，通过实施氮、钾养分的田间试验，运用同位素示踪技术，明确钾对甘薯碳、氮积累以及氮对碳、钾积累的影响，解析氮钾互作的生理机理；利用系统分析方法和动态建模技术，量化甘薯地上部氮、钾浓度与地下部最大干物重之间的定量关系，构建不同钾浓度下的临界氮浓度模型以及不同氮浓度下的临界钾浓度模型，并进一步构建甘薯氮、钾营养诊断模型和最适冠根比的生长诊断模型；最后，建立协调甘薯源库平衡的营养与生长综合诊断指标，量化内在营养指标与外在生长指标之间的关系，探明氮钾互作对甘薯源库平衡关系的影响，预期结果将为甘薯氮钾营养和长势状况的精确调控提供理论基础和技术支撑。

The premise to acquire high yield of sweetpotato is to coordinate the relationship between source and sink, and the key to solve the balance relationship between source and sink is the reasonable application of nitrogen and potassium. Therefore, it is of great significance to find out the effect of nitrogen, potassium nutrition and their interaction on the balance relationship between source and sink of sweetpotato on the rational application of fertilizer and the improvement of production level of sweet potato. According to the urgent demand for developing the potential production of sweetpotato, a series of field experiments will be carried out with different N and K application levels to detect the effect of the interaction of N and K on the balance of source and sink of sweetpotato. Through the application of isotope tracer technology, this study will make clear the effect of K on the accumulation of C and N and the effect of N on the accumulation of C and K in sweetpotato, and understand the physiological mechanism of the interaction of N and K. Then, the system analysis method and dynamic modeling technology will used to quantify the relationship between the concentration of N and K in the upper part of sweetpotato and the maximum dry matter weight in the underground. The critical nitrogen concentration model under different potassium concentration and the critical potassium concentration model under different nitrogen concentration will be constructed, and the nutrition diagnosis model of N and K and the growth diagnosis model of the optimum crown root ratio in sweetpotato will be further built based on the critical nitrogen and potassium concentration. Finally, based on above models, the nutrition and growth diagnosis indicators will be constructed. The relationship between two indexes will be clarified, which will be benefit to explore the effect of N and K interaction on the source sink balance of sweetpotato. The expected results will provide theoretical basis and technical support for the precise regulation of N, K nutrition and growth of sweetpotato.