玉米间作花生冠层微环境变化及其与荚果产量的相关性研究

Canopy microenvironment change of peanut intercropped with maize and its correlation with pod yield

  • 摘要: 种植模式是影响花生冠层内透光率、光照度、温度、湿度等微环境的重要因素。本试验分别在2015年度和2016年度田间试验中设花生单作、玉米/花生宽幅间作2个处理,监测不同种植模式下花生结荚期后冠层透光率、光照度、冠层温、湿度的变化规律,并分析其与荚果产量的相关性。结果表明:1)与花生单作相比,玉米/花生宽幅间作显著降低了花生冠层的光照度、冠层顶部和中部的透光率及上午9:00-11:00的平均温度;增加了冠层平均湿度。2)花生冠层光照强度在晴天随时间推延而呈先升后降的单峰曲线,且单作显著高于间作;在上午光照强度上升期和下午光照强度下降期,单作和间作光照强度差值较大,而中午太阳直射期二者差值减小。间作降低了花生夜间和中午前后的冠层环境温度,二者温差最高可达4.9℃;增加了白天冠层相对湿度,二者湿度差最高达21.03%。3)本试验条件下,结荚期冠层环境温度、冠层光照度及饱果期冠层环境温度、冠层光照度均与花生荚果产量呈极显著正相关;冠层环境湿度则与荚果产量呈负相关关系,其中结荚期达到极显著水平。多元线性逐步回归分析得出,影响产量的重要环境因素为结荚期冠层光照度、结荚期冠层相对湿度、饱果期冠层相对湿度。通径分析得出,光照度除了直接影响产量外还有很大部分效应是通过影响冠层环境湿度进而影响花生荚果产量,说明间作条件下协调好光照度和冠层湿度的关系可提高光照度对产量的正面影响效应。本试验条件下,间作花生冠层光照度、透光率下降,冠层相对湿度升高,是限制花生荚果产量提高的主要气候生态因子。建议生产中间作为东西向种植,从而提高间作花生冠层上午9:00-11:00的有效光照度、适当降低冠层相对湿度,以期提高间作花生荚果产量。

     

    Abstract: Field trials of the single cropping of peanuts and broad-sown intercropping of maize and peanuts were conducted in 2015 and 2016. Changes in peanut canopy transmittance, light intensity, canopy temperature, and humidity after the podding stage under different planting modes were monitored, and the correlations between them and pod yield were analyzed. Our results showed that, first, compared with a peanut monoculture, maize/peanut intercropping significantly reduced the light intensity of the canopy, the transmittance of the top and middle canopy, and the average temperature of the canopy from 9:00 a.m. to 11:00 a.m., and increased the average humidity of the canopy. Second, peanut canopy light intensity exhibited a single peak curve on sunny days, and the canopy light intensity of monocultured peanuts was significantly higher than that of intercropping. The difference in light intensity between a monoculture and intercropping was greater in the morning (when light intensity increased) and the afternoon (when light intensity decreased), while the difference between the two values decreased at noon during the direct-sunlight period. The ambient canopy temperature of peanuts decreased under intercropping in the night and before and after noon, compared with monoculture, with an observed highest difference of 4.9℃. Intercropping increased the relative humidity of the canopy during daytime, with a recorded highest difference of 21.03%. Third, under experimental conditions, the canopy environmental temperature and illumination at the podding stage were positively correlated with peanut pod yield, while the canopy environmental humidity was negatively correlated with pod yield, especially at the podding stage. Multivariate linear stepwise regression analysis showed that the most important environmental factors affecting peanut yield were canopy illumination and circumferential humidity at podding stage, and canopy circumferential humidity at the full-fruit stage. Path analysis showed that, besides directly affecting yield, illumination had a high impact on peanut pod yield by affecting canopy environmental humidity, indicating that the positive effect of illumination on yield can be improved by coordinating the relationship between illumination and humidity under intercropping conditions. In this experiment, the decrease in canopy light intensity and transmittance of intercropping and the increase in canopy relative humidity of intercropping were the main climatic factors limiting pod yield. It is possible that the yield of intercropped peanuts could be increased by planting them from east to west, which will increase the effective illuminance of the canopy at 9:00-11:00 a.m. and reduce the relative humidity.

     

/

返回文章
返回