###### Abstract  
The current study evaluated the canopy cover competition for light and heat in a jujuube-cotton intercropping system to measure the growth and yield performance of cotton, and the optimal cotton planting configuration. In this study, a two-year field experiment (2020 and 2021) was studied with different spacing configuration modes designed as follows: two rows of cotton (CM1) planted 1.4 m apart, four rows of cotton (CM2) planted 1.0 m apart, and six rows of cotton (CM3) planted 0.5 m apart, spacing intercropped juibue trees, respectively. The control treatment consisted of monocultured cotton (CK). The light-response curve was plotted using an LI-6400 kT photosynthesis instrument. Based on the modified rectangular hyperbola model, the photosynthetic characteristics were fitted, and the dry matter distribution characteristics and yield were compared. The results showed that with the increase in photosynthetically active radiation, the net photosynthetic rate (Pn) of each growth phase decreased first and then increased rapidly in the range of 0-200 umol-m\({}^{-2}\).s\({}^{-1}\) and then decreased slightly after the inflection point (light saturation point). The light-response curves of stomatal conductance and transpiration rate showed a linear relationship. The trend in the intercellular CO\({}_{2}\) concentration response curve was opposite to that of Pn. The maximum Pn (Pmax) of intercropped cotton was significantly impacted by configuration modes, of which CM2 treatment generated 1.8% and 22.8% higher Pmax than the CM1 and CM3 treatments. The cotton yield in the two years ranked as CK > CM3 > CM2 > CM1, and the average land equivalent ratio of CM2 was significantly higher than that of CM3 (22.4%) and CM1 (95.9%). The six-row configuration resulted in greater competition with the trees, which affected the accumulation of below-ground dry matter, while the four-row configuration formed a reasonable canopy structure, which ensured that more photosynthetic substances were distributed to the generative organs. The reasonable four-rows configuration mode may improve the photosynthetic efficiency of intercropped cotton economic yield. dry matter; jujuube-cotton intercropping; light-response curve; production; rectangular hyperbolic correction model 2023132427. 13. 2427.  
sustainability. Agroforestry systems that combine annual crops with trees have been widely used in semi-arid regions [3], and intercropping is currently implemented in Africa, Asia, Europe, and the Americas [4]. Intercropping allows crops to find their niche in time and space and promotes interspecific complementation to increase economic yield [5]. However, when crops require the same resources at the same time and space, then competition occurs. Growing cotton between rows of jujube trees as a companion crop is a common and profitable practice, especially during the young growth phase of jujube trees (less than 10 years). The jujube-cotton intercropping system is a complex system with high environmental heterogeneity [6]. The most intense competition factor between cotton crops and jujube trees in the intercropping system is light [7]. The blocking of light by high crops to low crops will affect the photosynthetic distribution above the canopy of the low crops, which will alter the photosynthetic characteristics and reduce the economic yield [8]. Approximately 90-95% of crop dry matter accumulation originates from photosynthesis. Existing studies have found that the main limiting factors of intercropping systems are field management, planting structure, density, and environmental conditions [9; 10; 11; 12]. The planting structure of jujube-cotton intercropping determines the resource competition, which affects the potential resource capture and optimal allocation of the system and directly affects the crop canopy structure, thereby influencing its photosynthesis and yield formation [13; 14].