宁夏盐池县粮食产量波动性及影响因子分析

为了探索农牧交错带农业系统的波动机制,有效减缓系统波动,利用多元逐步回归法、经验模态分解法(EMD)和集对分析法(SPA),分析了宁夏盐池县1954-2013年粮食总产量的波动特征及其影响因子。结果表明:(1)近60年盐池县粮食总产量以趋势性增长为主,其方差贡献率为82.86%,同时伴随着显著的波动,其方差贡献率为17.14%。存在3 a、6 a、9 a准周期波动,其中3 a准周期的波动强度最大。(2)农业机械总动力和灌溉耕地面积是引起粮食总产量趋势性增加的最主要影响因子,年降水量是引起粮食总产量3 a、6 a准周期波动的主要控制因子,粮食播种面积、化肥施用量为短期主控因子;引黄灌溉水量和有效灌溉面积为反向调节因子,其作用在粮食总产量突变点之后显著大于之前。(3)加强生态农业建设,促进气候依赖型农业向水文依赖型转变。

Analysis on fluctuation of grain yield and its influencing factors in Yanchi County, Ningxia Hui Autonomous Region

To study the mechanism and efficient alleviation of fluctuation in agricultural system of farming-pastoral transitional zone, fluctuation characteristics of gross grain yield from 1954 to 2013 at Yanchi County in Ningxia Hui Autonomous Region and the regulatory factors were analyzed with stepwise multiple regression, empirical mode decomposition (EMD) and set pair analysis (SPA). The results showed that the gross grain yield in Yanchi County was gradually increased during the past 60 years with the variance contribution at 82.86%. The distinct fluctuation in gross yield of grain accounted for 17.14% of variance. Gross grain yield presented the periodic fluctuation with quasi-periods of 3 a, 6 a and 9 a. Magnitude of the 3-year period was the greatest. In addition, the agricultural machinery gross power and irrigable farmland area were two main factors responsible for the gradual increase of gross grain yield. Annual precipitation predominantly regulated 3 a or 6 a quasi-periodic fluctuations of gross grain yield. Grain acreage and fertilizer input rate were the two control factors in short terms. Irrigation water diverted from the Yellow River and effective irrigation area were the negative regulatory factors, showing a significant influence after the occurrence of inflection point became stronger than that before. Furthermore, conversion of agriculture from climate-dependent to hydrology-dependent would be promoted as a result of strengthening the ecological agriculture construction.