Artificial Grassland Had Higher Water Use Efficiency in Year with Less Precipitation in the Agro-Pastoral Ecotone

Improving plant water use efficiency is a key strategy for the utilization of regional limited water resources as well as the sustainable development of agriculture industry. To investigate the effects of different land use types on plant water use efficiency and their mechanisms, a randomized block experiment was designed in the agro-pastoral ecotone of northern China during 2020-2021. The differences in dry matter accumulation, evapotranspiration, soil physical and chemical properties, soil water storage and water use efficiency and their relationships among cropland, natural grassland and artificial grassland were studied. The results show that: In 2020, the dry matter accumulation and water use efficiency of cropland were significantly higher than those of artificial and natural grassland. In 2021, dry matter accumulation and water use efficiency of artificial grassland increased significantly from 364.79 g center dot m(-2) and 24.92 kg center dot ha(-1)center dot mm(-1) to 1037.14 g center dot m(-2) and 50.82 kg center dot ha(-1)center dot mm(-1), respectively, which were significantly higher than cropland and natural grassland. The evapotranspiration of three land use types showed an increasing trend in two years. The main reason affecting the difference of water use efficiency was that land use type affected soil moisture and soil nutrients, and then changed the dry matter accumulation and evapotranspiration of plants. During the study period, the water use efficiency of artificial grassland was higher in years with less precipitation. Therefore, expanding the planted area of artificial grassland may be one of the effective ways to promote the full utilization of regional water resources.

Automated summary

Improving plant water use efficiency is crucial for utilizing limited water resources and ensuring sustainable development in agriculture industry. This study investigated the effects of different land use types on plant water use efficiency and their mechanisms, focusing on dry matter accumulation, evapotranspiration, soil properties, and water use efficiency. The results demonstrate that land use type significantly influences water use efficiency by affecting soil moisture, soil nutrients, and consequently, plant growth and evapotranspiration.