A New Method for Determining Critical Irrigation Period for Large Regions Based on Precipitation-Meteorological Yield Integral Regression Relationship—A Case Study of Winter Wheat in Shaanxi Province, China

Yongqiang Wang,Kongtao Jiang,Xiaoyi Ma,Rongheng Zhao,Ting Yang

doi:10.3390/app9235181

Yongqiang Wang, Kongtao Jiang + Show 3 more

Open Access

https://doi.org/10.3390/app9235181

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Abstract

Using the extremely limited water for deficit irrigation is a notable measure to improve crop yield in water shortage regions. Hence, determining a reasonable irrigation period in large regions is crucial. In this study, a simple and applicable process to determine the irrigation period in a large area by using the precipitation-yield integral regression method of crop growth period was proposed, and the winter wheat planting regions with a serious water shortage in Shaanxi, China were referred to as an example. According to the regional topography, soil, precipitation, temperature, and evaporation, the study area was first divided into four subregions; then, the rainfall water surplus and deficit characteristics of the subregions during the growth period of winter wheat were analyzed, and the precipitation-yield integral regression function of the subregions was calculated. In accordance with the sensitivity of rainfall to crop yield in different periods, the reasonable irrigation period of winter wheat in each subregion was determined. The results are basically consistent with irrigation habits of local farmers, and can be used to guide the irrigation of local winter wheat. They also demonstrate that the method has the advantages of requiring fewer data and being simple and reliable, and can overcome the problem that the existing method is difficult to determine the optimal irrigation period in the large-scale region, due to the lack of test points and representativeness. The proposed method application value in determining the deficit irrigation period with small water amount, in a large region lacking research materials.

Highlights

Global dryland occupies a large proportion of the total area of the earth [1], and current climate warming and rapid population growth trends are only increasing the risk of dryland area growth, especially in developing countries [2]
This study focused on determining the optimal irrigation period of winter wheat in the deficit irrigation regions with a small amount of water of Shaanxi Province mentioned above
Compared with the optimal irrigation period determined by the previous small area experiment, the method proposed in this study has the advantages of small workload and strong timeliness

Summary

Introduction

Global dryland occupies a large proportion of the total area of the earth [1], and current climate warming and rapid population growth trends are only increasing the risk of dryland area growth, especially in developing countries [2]. Water resources are scarce and cultivated land is fragmented, due to serious soil erosion, river channels, streams, dry gullies, poor agricultural infrastructure, and incomplete irrigation measures [3]. These problems have created severe food security challenges in these regions [4]. In regions where it is difficult to establish large-scale irrigation channels or pipelines to provide enough water for irrigation, only small-scale irrigation projects, such as water wells and rainwater harvesting projects, can be used to carry out limited irrigation with extremely limited water amount Several studies have investigated limit irrigation using small-scale water conservancy projects, such as rainwater harvesting projects [6]

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Conclusion