Apple trees exhibit adaptability to a wide range of climates and are among the most extensively cultivated fruit crops globally. As of 2023, China has emerged as the largest apple producer in the world, leading both in terms of apple cultivation area and total output. The northwest region is recognized as one of China’s primary apple-producing areas, characterized by ample sunshine, effective ventilation, and significant daily temperature fluctuations. This region experiences a dry climate with limited water resources, particularly in arid zones where irrigation is essential for crop growth. Furthermore, inefficient irrigation practices coupled with changing climatic conditions exacerbate the disparity between water supply and demand within the apple industry—especially in regions facing water scarcity. Consequently, this situation adversely affects apple production levels. It is evident that achieving sustainable development for the apple industry in arid regions necessitates the implementation of water-saving technologies alongside effective water management strategies.
Drip irrigation stands out as a modern water-efficient technology that addresses conflicts between agricultural and ecological water needs in resource-limited areas. Notably, soil evaporation plays a distinctly different role within ecosystems compared to transpiration: while transpiration directly contributes to agricultural productivity, soil evaporation often detracts from it and is generally viewed as an undesirable factor. Therefore, enhancing our understanding of soil evaporation characteristics specific to young apple orchards is crucial for selecting suitable water-saving measures and maximizing the production potential of these orchards in regions experiencing water scarcity. Therefore, it is necessary to explore soil evaporation characteristics in young apple orchards served by a combination of drip irrigation and mulching practice in water-limited regions.
To solve this problem, we conducted a field experiment at Shiyanghe Experimental Station, China Agricultural University, located in Wuwei, Gansu Province in northwestern China. The study area has a continental temperate arid climate, with an average annual temperature of 8 °C. The mean annual sunshine hours exceed 3000 h, and the annual average cumulative temperature is more than 3550 °C. Water resources are scarce in this region, with an annual precipitation of 164 mm. The mean annual pan evaporation is about 2000 mm and the groundwater depth ranges from 40 to 50 m.
Through the experiment, we came to the following conclusion: film mulching and straw mulching practices significantly reduced soil evaporation losses in young orchards with drip irrigation. There was no significant difference in daily soil evaporation of the young orchard between film mulching and straw mulching treatments. The daily soil evaporation of this young apple orchard under film mulching and straw mulching treatments was more responsive to meteorological factors than those under clean tillage treatment. Daily soil water content in the 0–120 cm soil profile of straw-mulched apple orchards was always higher than that of the film-mulched and clear-tilled treatments, whereas there was no significant relationship between daily soil evapotranspiration and soil water content in the different soil horizons of the treatments. The results of this study emphasise the significant differences in soil evaporation dynamics and soil moisture status between the different mulching treatments. As a result, straw mulching practices should be carefully considered when selecting appropriate mulching practices in young orchards with drip irrigation in this region. In the future, the estimation of soil evaporation and soil water content can be combined with transpiration and water use efficiency measurements, which can further improve understanding of the effects of the combination of drip irrigation and mulching practices on the water use characteristics of young orchards in arid or similar climatic regions.
This study was published in Frontiers of Agricultural Science and Engineering in 2024, 11(4) DOI: 10.15302/J-FASE-2024563.