Film mulching combined with chemical fertilizer increased rice yield by promoting the accumulation of photosynthetic substances in the vegetative growth stage

The plastic film mulching technique can mitigate the yield-limiting effects of low-temperature chilling injury on rice yield in Northeast China, while rational fertilization practices contribute to improved soil quality. However, research remains scarce regarding the combined effects of plastic film mulching with different fertilizer types on rice dry matter accumulation and translocation, and the underlying mechanisms governing their roles in rice yield formation remain unclear. This study used "Jinongda 738" and "Jijing 525" as experimental materials and set up four different cultivation modes: 1) Bare land with organic fertilizer application (NMF0); 2) Plastic-mulched land with organic fertilizer application (MF0); 3) Bare land with chemical fertilizer application (NMF1); 4) Plastic-mulched land with chemical fertilizer application (MF1). The study aimed to explore the effects of plastic film mulching and different types of fertilizers on the growth of rice and the transportation of photosynthetic substances. Compared with bare land, film mulching improved the agronomic traits of rice. Under mulching conditions, chemical fertilizers increased the relative chlorophyll content (SPAD) and net photosynthetic rate (Pn) of leaves from the tillering stage to the heading stage, which was beneficial for the accumulation and transportation of dry matter. Under the same mulching conditions, the application of organic fertilizer slowed down the decline of photosynthesis from the grain filling stage to the maturity stage. Compared with the bare land treatment, under the combined application of chemical fertilizers and organic fertilizers, the film mulching treatment increased the yield by 2.98% to 3.30% and 1.39% to 7.40% respectively.Compared with the application of organic fertilizers, under bare land and film mulching conditions, the application of chemical fertilizers increased the yield by 23.19-26.44% and 21.62-25.13% respectively.Under the conditions of this experiment, MF1 had the best yield-increasing effect, with an increase of 2.98% to 30.62% compared to other treatments. It was a superior treatment method. This research aims to provide a theoretical basis for achieving green and efficient rice production.