Adaptive sowing window strategy for improving grain filling and water loss characteristics of film-mulched maize in Northwest China

Abstract

Context

High yield and mechanization are essential goals in modern crop production. However, sowing strategies that maximize yield and mechanical harvesting efficiency in film-mulched maize remain understudied.

Objective

This study aimed to optimize the sowing window to create better water and temperature conditions, improve grain filling and water loss characteristics, and ultimately achieve mechanically harvestable high yields in film-mulched maize.

Methods

A two-factor field experiment was conducted over two consecutive years (2021–2022) in Northwest China, incorporating two planting methods (film-mulch vs. no-mulch) and four sowing dates (April 10 to May 16).

Results

Film-mulch planting increased soil temperature, accelerating maize phenological development and shortening the growth period compared with no-mulch planting. Notably, it increased the growing degree days (GDD) by 32.4–173.5 °C d but reduced plant available water (PAW) by 25.2–39.9 % during grain filling period. These changes increased grain filling rate (GFR) by 27.7–45.5 % and water loss rate (GWLR) by 2.2–15.1 %, ultimately promoting grain yield by 153.9–199.6 % and advancing mechanical harvesting date by 24–33 days. Early sowing maximized yield and harvest efficiency in water-sufficient year, while delaying sowing window to April 22–May 6 for film-mulched maize (compared with April 18–28 for no-mulch) can mitigate drought stress risks from accelerated development, thereby ensuring both yield stability and mechanical grain harvesting.

Conclusions

A one-week sowing delay is recommended for film-mulched maize compared with no-mulched pattern. This adaptive sowing window strategy can balance yield improvement and mechanical harvesting compatibility in semi-arid regions with limited and variable precipitation.