Photosynthetic and Chlorophyll Fluorescence Responses in Maize and Soybean Strip Intercropping System

In this study, the photosynthetic mechanisms and superiority of the systematic economic output value of crop yield in a maize- soybean intercropping system was determined. The effects of maize and soybean single cropping, and strip intercropped maize and soybean under four different intercropping ratios of the two crops [maize (M): soybean (S): 2:2, 4:2, 4:4, and 6:6] were compared and analyzed the changes in photosynthetic performance, chlorophyll fluorescence, and yield components-Results showed that strip intercropping effectively improved the light response curve of maize and significantly reduced in soybean which improved the adaptability of functional leaves of maize to strong light. Maize intercropping had more open stomata, higher intercellular CO2 concentration and higher transpiration rate. Strip intercropping significantly improved the Fv/Fm, qP and Phi PSII value of maize leaves, and each parameter of soybean strip intercropping changed in contrast. The photosynthetic capacity of crops in different strip width was also different under intercropping. The photosynthetic capacity of maize in the strip was gradually reduced with the increase of strip width, while of soybean was gradually restored. Based on these changes in photosynthetic capacity, intercropping significantly increased the yield components of maize, and significantly decreased the yield components of soybean. As a result, the yield in maize strip was significantly higher than in single. However, the compound yield of strip intercropping was all higher than soybean single. In this study, intercropping advantage existed in different strip intercropping treatments and the compound economic output value of crops in each treatment was higher than maize and soybean single, among which maize-soybean 4:2 strip intercropping was the largest compound economic output value and the smallest was soybean single cropping. (C) 2020 Friends Science Publishers