Effect of Straw Mulch on Soil Evaporation during Freeze–Thaw Periods

Junfeng Chen,Xue Xie,Xiuqing Zheng,Qi Du,Yongxin Xu,Jing Xue,Chunyan Miao

doi:10.3390/w11081689

Abstract

Reducing soil evaporation is important to alleviate water shortages in arid and semi-arid regions. The objective of this work was to reveal the effect of straw mulch on soil evaporation based on field experiments during a freeze–thaw period in Northern China. Four soil surface mulch treatment modes were investigated: Bare soil (BS), 1 cm thick straw mulch with 100% coverage rate (J1), 2 cm thick straw mulch with 100% coverage rate (J2), and 2 cm thick straw mulch with 50% coverage rate (J3). Principal component analysis was used to analyze the major factors influencing soil evaporation in three freeze–thaw stages. The results show that cumulative soil evaporation decreased with increased straw mulch thickness and coverage rate. The effect of straw mulching on soil evaporation was obvious during the stable freezing period, and soil evaporation with straw mulch treatments was reduced by 49.0% to 58.8% compared to BS treatment, while there was little difference for straw mulch treatments in the thawing stage. The relationship between cumulative soil evaporation under different straw mulch modes and time was well fitted by the power function. In the unstable freezing stage, the major factors for all treatments influencing soil evaporation were surface soil temperature and water surface evaporation; in the stable stage, they were solar radiation and relative humidity, and in the thawing stage, they were solar radiation and air temperature. The research results can provide a basis for addressing soil water storage and moisture conservation and restraining ineffective soil evaporation in arid and semi-arid areas.

Highlights

Soil evaporation is the main process in the consumption of soil moisture, changes of which directly affect the management of soil water and the improvement of the agricultural crop yield [1]
In order to reduce the ineffective loss of soil moisture caused by soil evaporation and improve crop water use efficiency, the method of soil surface mulching is often used in production
The objectives of this study are to (1) quantify soil evaporation under different straw mulch modes during freeze–thaw periods, (2) identify the influences of straw mulch on soil evaporation during freeze–thaw periods; and (3) analyze the major factors that influence soil evaporation under different straw mulch modes in different freeze–thaw stages

Summary

Introduction

Soil evaporation is the main process in the consumption of soil moisture, changes of which directly affect the management of soil water and the improvement of the agricultural crop yield [1]. In arid and semi-arid areas, it is estimated that 50–70% of precipitation is lost by soil evaporation without any contribution to crop production [2,3]. In order to reduce the ineffective loss of soil moisture caused by soil evaporation and improve crop water use efficiency, the method of soil surface mulching is often used in production. As a well-established technique used worldwide, especially in arid and semi-arid areas, soil surface mulching has favorable effects in terms of improving soil temperature and reducing soil

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Results

Conclusion