春小麦氮素吸收、积累与分配规律的研究

为了给小麦高产栽培合理施肥提供理论依据，本试验采用五因素二次通用回归旋转组合设计方法，系统地研究了春小麦在不同密度、施肥处理下氮素的吸收、积累、分配和转移规律。结果表明，春小麦一生中植株体内氮素含量在苗期至分蘖末期最高，为3．10％左右，此后随生育进程的推进逐渐下降，到完熟期下降至一生中最低值。春小麦全生育期中氮素吸收高峰在拔节至孕穗期，且在不同密度和施肥处理下，高密和高氮处理氮素吸收高于其他处理。春小麦一生中，氮素积累量与生育进程间符合S型曲线变化。各器官氮素的分配，生育前期主要以营养器官叶、茎鞘为主，生育后期则主要分配在籽粒中。叶片氮素的转移发生在孕穗之后，茎鞘氮素转移时期因不同处理而异，而穗部氮素转移发生在开花后。

Rules of N Assimilation, Accumulation and Distribution of Spring Wheat

The rules of nitrogen assimilation, accumulation, distribution and transportation were systematically studied by means of five-factor quadratic orthogonal regressive rotation combination design. The results showed that the N content in spring wheat plant was the maximum of about 3. 10% during the period from seedling stage to the end of tillering stage, and descented gradually with growth, then reached the minimum in maturity. The N absorption of spring wheat peaked during the period from jointing to booting, and N absorption of high density and high N application was higher than that of other treatments. The change of N accumulation in the course of growing accorded with S-curve. The N distribution was mainly in nutritious organs (such as leaf stem and sheath) in the former of its life and mainly in grains in the later of its life. The N transportation in leaf began with booting stage. The period of N transportation in sheath differs from different treatments, and N in spike began with flowering stage.