The Effectiveness of Mulching in Improving Water Use Efficiency of Spring Maize in Hetao Irrigation District Varied with Types of Plastic Films

Abstract

【Background and objective】 Mulching has been widely used in agricultural production in Hetao irrigation district of Inner Mongolia to improve soil temperature and reduce soil water evaporation. However, if and how film types such as their color and materials affect evapotranspiration and water use efficiency of crops is an issue that is largely elusive. The purpose of this paper is to experimentally address this knowledge gap. 【Method】 The experiments were conducted at a spring maize field, with the soil surface mulched by either black plastic film (M2) or transparent plastic film (M1). No-mulching was taken as the control (CK). During the experiment, we measured the changes in soil moisture, evaporation and evapotranspiration in each treatment. The water use efficiency and water consumption of the maize in each treatment were calculated based on water balance in the root-zone soil. 【Result】 Regardless of the film types, mulching significantly increased the water in 0~120 cm soil because of the reduced evapotranspiration, with the evapotranspiration and evaporation under black and transparent plastic films reduced by 6.10% and 8.18%, and 28.43% and 33.20%, respectively, compared to those in the CK. These hence increased the bioavailable water to the maize and the eventual yield. In particular, M1 and M2 increased the maize yield by 22.83% and 10.31%, and water use efficiency by 30.79% and 20.12%, respectively, compared to CK. Water consumption in M1 was more than that in M2, but water movement from the subsoil to the topsoil at the late growth stage boosted crop yield and increased its water use efficiency as a result. 【Conclusion】 Plastic film mulching of the spring maize in Hetao irrigation district reduced the evapotranspiration, and consequently increased its yield and water using efficiency. Comparison revealed that mulching with the transparent film is more effective and agronomically suitable for the studied region.

Keywords

• spring maize
• transparent plastic film
• black plastic film
• evapotranspiration
• evaporation
• water use efficiency