Residual film pollution in fields is the main problem affecting the sustainable development of agriculture. Cultivation without plastic mulching is the best way to reduce the accumulation of residual film. Therefore, we investigated the effects of three depths of embedded drip irrigation belts (10 cm, 15 cm and 20 cm) on the photosynthetic traits and yield of cotton without plastic mulching. From Biologische Bundesanstalt, Bundessortenamt and Chemical industry (BBCH) 65 to 75, the cotton leaf

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... ea of the 10 cm and 15 cm treatments decreased by 45.0% and 25.4%, respectively, while the cotton leaf area of the 20 cm treatment increased by 8.3%. With increasing depth, the SPAD value, net photosynthetic rate, intercellular CO2 concentration, transpiration rate, stomatal conductance, quantum efficiency of PSII, electron transport rate, photochemical quenching coefficient and maximal quantum yield of PSII photochemistry increased. Compared with the 10 cm and 15 cm treatments, the biological yield of the 20 cm treatment was 51% and 33% higher, and the seed cotton yield was 15% and 2% highter, but the economic coefficient was 24%, lower. Hence, 15 cm is the optimum depth to enhance the photosynthetic capacity and ensure the maximum economic coefficient of cotton without plastic mulching.