Abstract: The empirical distribution of the difference between yield deviations, simply Dd distribution, derived from 84 rice fertilizer field experiments (2352 plots) dispersed in 15 provinces of China was studied by means of computer. The results showed that the Dd distribution was symmetric, leptokurtic and significantly different from normal distribution. The cumulative probability distribution function F(X) of Dd could be computed by: F(X) =Pr (Dd≤X) = 1-0. 5 × 10-0.0020987X (Dd≥0). The Dd distribution could be applied to the comparisons of the treatments in dispersed experiments with single replication.

Key words: distribution of the difference between yield deviation, cumulative probability distribution function, fertilizer field experiments, statistical method

摘要： 利用按统一试验方案布置于中国15个省84个水稻肥料试验点共2352个小区产量资料，借助于计算机对水稻肥料试验产量离均差差数分布（简称Dd分布）作了研究，结果表明，Dd分布与正态分布有显著差异，为对称高狭峰分布，Ｄｄ累积分布呈指数分布，其累积概率分布函数Ｆ（x）的计算式为：F(X) =Pr (Dd≤X) = 1-0. 5 × 10-0.0020987X (Dd≥0).。Dd分布可用于多点无重复试验中处理间产量比较。

关键词: 离均差差数分布, 累积概率分布函数, 大田肥料试验, 统计方法