Plastic film mulching combined with nitrogen fertilization can significantly increase maize yield and maintain soil water balance in semiarid regions. A seven-year study showed that the combination of mulching and nitrogen application had the highest sustainability yield index. Mulching increased soil water content and storage, preventing the formation of dry soil layers. Precipitation storage efficiency in the nongrowing season was positively affected by mulching, helping to maintain soil water balance. The research suggests that using plastic film mulching throughout the year can help farmers store more precipitation, crucial for crop growth in semiarid environments.