Zhao Kun, Qu Yan, Wang Deping, Liu Zhongkuan, Rong Yuping
College of Grassland Science and Technology, China Agricultural University, Beijing 100193, China.
Institute of Agro-Resource and Environment, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, China.
Plants (Basel). 2023 Mar 9;12(6):1239. doi: 10.3390/plants12061239.
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·m and 24.92 kg·ha·mm to 1037.14 g·m and 50.82 kg·ha·mm, 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.
提高植物水分利用效率是区域有限水资源利用以及农业产业可持续发展的关键策略。为探究不同土地利用类型对植物水分利用效率的影响及其机制，于2020 - 2021年在中国北方农牧交错区设计了随机区组试验。研究了农田、天然草地和人工草地在干物质积累、蒸散、土壤理化性质、土壤储水量和水分利用效率方面的差异及其相互关系。结果表明：2020年，农田的干物质积累和水分利用效率显著高于人工草地和天然草地。2021年，人工草地的干物质积累和水分利用效率分别从364.79 g·m和24.92 kg·ha·mm显著提高到1037.14 g·m和50.82 kg·ha·mm，显著高于农田和天然草地。三种土地利用类型的蒸散在两年内均呈增加趋势。影响水分利用效率差异的主要原因是土地利用类型影响土壤水分和土壤养分，进而改变植物的干物质积累和蒸散。在研究期间，降水较少年份人工草地的水分利用效率较高。因此，扩大人工草地种植面积可能是促进区域水资源充分利用的有效途径之一。
