黄淮南部玉米产量对气候生态条件的响应

针对近年来黄淮南部气候条件和耕作制度变化, 2015—2016年在河南农业大学科教园区以该区主推品种郑单958为材料, 采用分期播种方法, 研究玉米产量对气候生态条件的响应, 探讨气候因子与玉米产量的关系。结果表明, 由于年际间、播期间气候因子的差异, 玉米产量差异显著, 大体表现为春播产量高于夏播, 且夏播产量随播种时间的推迟而显著降低。随着播期的推迟, 玉米苗期日均温逐渐升高, 粒期日均温逐渐降低, 有效积温减少, 生育期缩短。试验设定密度下, 百粒重对产量的贡献大于穗粒数, 而影响百粒重和穗粒数的主要气候因子是全生育期有效积温和粒期有效积温。影响玉米产量的主要气候因子是苗期气温日较差(r = 0.696^*)和日均温(r = -0.638^*)、粒期有效积温(r = 0.822^**)和日均温(r = 0.723^**)、生育期有效积温(r = 0.843^**)。因此, 生产上, 春播玉米播期由传统的4月15日左右推迟至5月1日左右, 可减少花期阴雨和高温热害影响, 表现出较好的丰产稳产性。夏播玉米在麦收后抢时早播, 不仅可争取更多积温, 还可使玉米苗期处于较低日均温、粒期处于较高日均温的有利温度条件下, 同时为推迟收获期和机械粒收创造条件。

Response of Maize (Zea mays L.) Yield to Climatic Ecological Condition on the South Yellow-Huaihe-Haihe Rivers Plain

In view of the changes of climatic condition and farming system in recent years, a field experiment during growing season 2015-2016 was conducted to study the responses of maize yield to ecological condition, and discuss the effects of climatic factors on maize yield under condition of different sowing dates on the south Yellow-Huaihe-Haihe Rivers plain. A main maize cultivar Zhengdan 958 was sown at seven sowing dates (S1: 15 April; S2: 30 April; S3: 15 May; S4: 30 May; S5: 14 June; S6: 29 June; S7: 14 July). There was significant difference in maize yield because of the different climatic conditions between years and between conditions of sowing dates. The yield of spring-sowing maize was significantly higher than that of summer-sowing maize, which deceased significantly with postponing sowing date. With postponing maize sowing date, the average daily temperature during seeding stage increased, the average daily temperature from anthesis to maturity and growing degree-days during whole growth period decreased, and the growth period of maize shortened gradually. At the density of 67 500 plants ha^-1,100-grain weight made more contribution to yield than grain number per ear. The main climatic factors affecting 100-grain weight and grain number per ear were growing degree-days during whole growth period, especially from anthesis to maturity stage. The main climatic factors affecting maize yield were the average daily temperature range (r = 0.696^**) and average daily temperature (r= -0.638^*) at seedling stage, the growing degree-days (r = 0.822^**) and average daily temperature (r = 0.723^**) from anthesis to maturity stage, and the growing degree-days during whole growth period (r = 0.843^**). Therefore, the sowing date of the spring-sowing maize can be postponed from the midmonth of April to May 1st, which can achieve high and stable grain yield because of decreasing the harmful effects of cloudy and rainy at flowering and high temperature heat damage. For summer maize, the suitable sowing date should be as early as possible after wheat harvest. The early sowing date of summer maize not only increase growing degree-days, but create suitable temperature condition that the average daily temperature is low during seedling stage and high from anthesis to maturity stage, and provide suitable condition for delaying harvest and facilitating mechanical grain-harvest.