Abstract: A meta-analysis was conducted to examine the effects of plastic film mulching on peanut yield, water use efficiency, and nitrogen partial factor productivity in northern China from 1981 to 2021. The differences in yield-enhancing effects of plastic film mulching were mainly explored under various influencing factors through subgroup analyses. The results showed that plastic film mulching increased peanut yield, water use efficiency, and nitrogen partial factor productivity by 20.0%, 36.2%, and 20.8% (P<0.05), respectively. Results of random forest analysis showed that climatic conditions were the most critical factor impacting the yield-enhancing effect of plastic film mulching in northern China. Subgroup analyses showed that plastic film mulching had the most significant effect on peanut yield enhancement in Northwest China, followed by Northeast China, and the lowest in North China, with yield increases of 35.4%, 21.6%, and 15.9% (P<0.05), respectively. The yield of peanut under plastic film mulching in northern China increased the most (by 58.9%) between 1991 and 2000, and the lowest (by 14.8%) between 2011 and 2021. Under natural conditions of annual precipitation of 400-600 mm, annual average temperature <12 ℃, sandy loam soils or soils with an organic matter content of <20 g·kg^-1, plastic film mulching had stronger yield-enhancing effect. In terms of field management measures, peanut yields increased more significantly under plastic film mulching when applied in water permeable film, spring sowing, flatten culture, planting density <150000 holes·hm^-2, split fertilization, nitrogen application < 90 kg·hm^-2, phosphorus application < 60 kg·hm^-2 or potassium application > 210 kg·hm^-2. Therefore, peanut mulching should be adopted in the arid, semi-humid, and low temperature areas in northern China. The effect of mulching on yield increase should be more efficient by adjusting field management measures. This study can provide theoretical guidance for peanut mulching planting in northern China.

Key words: peanut, plastic film mulching, yield, water-nitrogen use efficiency, influencing factor, meta-analysis