小麦高产高效植株临界氮浓度及其调控机制

Overuse of nitrogen fertilizer has occurred widely in Chinese agriculture,China is facing great challenges in both food security and environmental sustainability against the background of global climate change,therefore achieving high yield and high nitrogen use efficiency simultaneously is very important and urgent in wheat production.Typical filed analysis,field experiment and pot experiments will be used to understand the mechanism and applied basic research of increasing wheat yield and nitrogen use efficinecy synchrony.The main research contents includes:(1)to understand the characteristic of wheat population dynamic and plant nitrogen under different varities, yield ,and nitrogen rate,to find the plant critical nitrogen concentration and key period for high yield and high nitrogen use efficiency,(2) to understand the relationship between plant nitrogen concentration and population dynamic under various varities,nitrogen rates ，to find the plant critical nitrogen concentration and key period;(3)to disscuss the responding mechnism of population dynamic on low and high plant nitrogen concentration ,to know the deffirence between different wheat populations,to understand the interaction mechanism of plant nitrogen with population dynamic.(4)to discuss the effect of nitrogen regulation with different nitrogen rates ,nitrogen form and application method based on plant critical nitrogen concentrtion .

针对当前农业生产中小麦高产和氮素高效难于协调的问题，通过典型田块剖析、田间小区试验和生物模拟试验相结合，（1）研究不同小麦品种、不同产量、不同施氮水平下小麦群体茎蘖动态变化和植株不同器官氮浓度变化特征，明确高产高效小麦群体变化特征和植株氮浓度变化，了解构建小麦高产高效群体的关键时期和植株氮浓度特征。（2）研究不同小麦品种、不同供氮水平下植株不同器官氮浓度变化与群体茎蘖动态之间的关系，明确影响小麦高产高效群体的植株临界氮浓度和关键时期。（3）研究不同生育期小麦群体茎蘖动态对植株氮浓度过低或过高的响应，比较不同类型小麦群体对供氮反应的差异，明确小麦植株氮浓度与群体茎蘖动态的互馈机制。（4）根据植株临界氮浓度指标，研究在不同植株氮浓度（低于、超过植株临界氮浓度）条件下，关键时期不同氮肥形态、不同施肥方式、不同氮肥用量氮素调控对小麦群体茎蘖消长、分蘖成穗的影响，探讨氮素调控的指标和增产增效的机

本项目针对当前农业生产中小麦高产和氮素高效难于协调的问题，通过典型田块剖析、田间小区试验，（1）研究了不同小麦品种、不同产量、不同施氮水平下小麦群体茎蘖动态变化和植株不同器官氮浓度变化特征，找到了高产高效小麦群体变化特征和植株氮浓度变化规律，明确了构建小麦高产高效群体的关键时期和植株氮浓度特征。（2）研究了不同小麦品种、不同供氮水平下植株不同器官氮浓度变化与群体茎蘖动态之间的关系，找到了影响小麦高产高效群体的植株临界氮浓度和关键时期。（3）研究了不同生育期小麦群体茎蘖动态对植株氮浓度过低或过高的响应，比较了不同类型小麦群体对供氮反应的差异，明确了小麦植株氮浓度与群体茎蘖动态的互馈机制。（4）根据植株临界氮浓度指标，研究了在不同植株氮浓度（低于、超过植株临界氮浓度）条件下，关键时期不同氮肥形态、不同施肥方式、不同氮肥用量氮素调控对小麦群体茎蘖消长、分蘖成穗的影响，明确了氮素调控的指标和增产增效的机理。本项目可为小麦产量和氮肥利用效率协同提高提供理论依据。