Estimation of Evapotranspiration and Crop Coefficient of Chinese Cabbage Using Eddy Covariance in Northwest China

Jie Ding,Yunxuan Zhang,Sien Li,Danni Yang,Chunyu Wang,Hongshuo Wang

doi:10.3390/w13192781

Jie Ding, Yunxuan Zhang + Show 4 more

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https://doi.org/10.3390/w13192781

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Abstract

Chinese cabbage is a key vegetable crop in northwest China. It is of great significance to study the evapotranspiration (ET) and crop coefficient (Kc) for agricultural water-saving management in this area. Eddy covariance (EC) was used to measure the ET and Kc of Chinese cabbage in northwest China from 1 May to 16 October 2020, in order to analyze the characteristics of these variables under plastic mulch. The results showed that the average Kc of the first crop of cabbage was higher in the middle and late stages, with values of 1.08 and 1.09 during the heading and maturity stages, respectively. The average Kc of the second crop of cabbage was higher in the middle stage, with values of 1.10 and 1.13 during the rosette and heading stages, respectively. The average annual Kc of Chinese cabbage was 0.81. Although Kc was higher in the middle and late periods, the water use efficiency was still 28.96 kg·ha−1·mm−1. The annual ET of Chinese cabbage was 505.3 mm. The study revealed the variation pattern of ET and Kc of Chinese cabbage, which provides an important scientific basis for the irrigation management of Chinese cabbage and is of great significance to guide the practice of water-saving vegetable planting.

Highlights

In recent decades, with the continuous population growth and development of the social economy, the demand for water resources has increased rapidly in world
In the arid region of northwest China, about 10% of the area receives agricultural irrigation, and irrigation accounts for the largest part of available water consumption
The results from the water balance method were used to test whether the ET measured by the eddy covariance method was reliable

Summary

Introduction

With the continuous population growth and development of the social economy, the demand for water resources has increased rapidly in world. In northwest China, leads to environmental degradation and limits regional economic development and social progress [1,2]. In the arid region of northwest China, about 10% of the area receives agricultural irrigation, and irrigation accounts for the largest part of available water consumption. ET can reach 95% of the water balance [10]. The main form of agricultural water consumption is crop evapotranspiration (ET). The key to water saving in agriculture is to reduce crop evapotranspiration. The determination of agricultural water management practices, the design of irrigation systems and irrigation regimes, and the calculation of crop yields are all based on accurate ET estimation [11]

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Results

Conclusion