Quantifying the differences in the effects of management practices on maize yield and water use efficiency in the North China Plain and Northwest China: A meta-analysis

Abstract

Context

The North China Plain (NCP) and Northwest (NW) China are both crucial maize-producing regions; but their management practices, such as water management, nitrogen management, mulching and straw return, differ significantly. In the NCP, maize production primarily relies on seasonal precipitation, while the NW region depends heavily on irrigation. Quantifying the differences in the effects of these management practices on maize yield and water use efficiency (WUE) between the NCP and NW is challenging due to variations in geographic location, climate, soil properties, and human factors.

Objective

The objectives of this study were to quantify the differences in the impacts of different management practices on maize yield and WUE between the NCP and NW, and assess the relative importance of these management practices on maize yield and WUE in each regions.

Method

This study conducted a comprehensive meta-analysis of 1058 datasets from the NCP and NW, providing insights into the differences in the effects of management practices on maize yield and WUE. In addition, random forest analysis was employed to quantify the importance of different management practices on maize yield and WUE in the two regions.

Results and conclusions

The management practices had a greater effect on maize yield and WUE in the NW than that in the NCP, attributed to the NW's lower precipitation, soil organic carbon and total nitrogen contents. Among these practices, nitrogen management had the most significant impact on yield and WUE, followed by mulching practices, straw return, and water management. Specifically, drip irrigation significantly increased maize WUE by 31.0 % compared with flood irrigation. The most pronounced improvements in yield (71.1 %) and WUE (64.6 %) were observed at a nitrogen application rate of 150–225 kg ha⁻¹. Additionally, plastic film mulching demonstrated more significant yield and WUE compared to straw mulching. Mild deficit irrigation improved WUE without significantly affecting yield, while severe deficit irrigation increased WUE but significantly reduced yield. Nitrogen management and mulching practices improved maize yield and WUE in the NW more effectively compared with the NCP. In the relative importance analysis, considering environmental factors (meteorological and soil factors), nitrogen application and irrigation amounts were essential for affecting maize yield and WUE in the NW, whereas irrigation amount and seasonal precipitation were more critical in the NCP.

Significance

This study provides scientific support for improving maize yield and WUE in both the NCP and NW through specific management practices.