Effects Of Different Film Mulches On Photosynthetic Characteristics And Yield Of Summer Maize (Zea Mays L.) In The North China Plain

Summer maize (Zea mays L.) is a globally essential food crop. To find the optimal mulch for summer maize, we explored the photosynthetic characteristics and yield of maize under different mulches. Four treatments were used during the 2016-2018 summer maize growing seasons: no mulch (CK), transparent film mulch (PF), biodegradable transparent film mulch (WF), and biodegradable black film mulch (BF). Thirty days after mulching, soil temperatures decreased in the order WF>PF>BF>CK. In all growing seasons, the chlorophyll content index (CCI) of maize was highest with BF. In 2016, the CCI with BF was 17.3%, 8.2%, and 13.2% higher than that with CK. At the flowering and filling stages, the net photosynthetic rate was highest with BF and lowest with PF. Meanwhile, the leaf water-use efficiency at the filling stage was 12.7% and 15.1% higher with BF than that with CK in 2017 and 2018, respectively. The 1000-kernel weight with BF was 8.9% and 2.5% higher than that with CK in 2016 and 2017, respectively, and the GY was 14.8% and 10.2% higher. These results indicate that biodegradable black film mulching is a feasible measure to improve the photosynthetic capacity and yield of maize in the North China Plain.