小麦生产的实践证明,在生产水平较低的情况下,随着播种量的适当增加,每亩有效穗也随之增加,产量常有较大幅度的提高.但是,近年来,由于施肥水平的上升,仍然维持较高的播种量,往往因群体发展过大,不少田块的每亩最高苗数竟达120万以上,造成田间早期郁闭,通风透光差,茎杆细弱,抽穗后遇到风雨,常招致倒伏,影响产量.根据调查,在较高施肥水平下,如能 The practice of wheat production proves that in the case of low production level, the effective spike per acre also increases with the appropriate increase of seeding rate, and the yield often increases greatly.However, in recent years, due to the level of fertilization Rise, still maintain a high seeding rate, often due to the development of groups is too large, many plots of the highest number of acres per acre actually reached more than 1.2 million, resulting in early field canopy, ventilation and poor light, stem thin, after heading Encounter with the wind and rain, often lead to lodging, affecting output.According to the survey, at higher fertilization levels, if