Effects of Field Microclimate on Physiological and Ecological Indexes of Cotton under Intercropping Mode

【Objective】 To explore the effects of farmland microclimate on cotton physiological index under intercropping mode. 【Method】 In this project, the canopy temperature, the canopy humidity and physiological indexes of cotton under different planting modes were analyzed and measured by field experiment and pot experiment. 【Result】 The results showed that the retention time of plant transpiration and soil evaporation water in the near-earth surface layer of intercropping cotton was prolonged, the canopy humidity was increased by 15.07%. The decline of the canopy air temperature was delayed at night. With the increase of relative humidity, the plant height, leaf area index and net photosynthetic rate of intercropping cotton were increased 26.61%, 19.42% and 10.25% respectively. The plant height, leaf area index and net photosynthetic rate of intercropped cotton were increased by 21.37%, 14.02% and 12.55% respectively when the underground competition was ignored. The variation amplitude was slightly smaller than that of the field experiments. 【Conclusion】 Intercropping mode mainly changed the relative humidity of farmland microclimate and improved the physiological index of cotton, which laid a good foundation for high yield. Compared with monoculture, the yield of intercropping cotton increased about 20%.