Institute of Agricultural Sciences, Federal University of Jequitinhonha and Mucuri Valleys, Avenida Universitária, no 1.000, Bairro Universitários, Unaí 38610-000, Brazil E-mail:
Water Sci Technol. 2022 Mar;85(5):1648-1657. doi: 10.2166/wst.2022.075.
Reuse of constructed wetlands effluents for fertigation is a promising practice in regions that suffer from water scarcity. Thus this study aimed to evaluate the influence of Vetiver (Chrysopogon zizanioides) and Tifton 85 (Cynodon sp.) grasses cultivation on salinity of the saturated solution of the Horizontal Subsurface Flow Constructed Wetlands (HSSF-CW) porous medium. The grasses were cultivated in HSSF-CW mesocosm and submitted to different levels of salinity for six months. The crop's evapotranspiration, biomass productivity, the electrical conductivity variation (ΔEC) in the solution under treatment and the water use efficiency (WUE) of these grasses were evaluated. The cultivation of Vetiver and Tifton 85 in HSSF-CW provided an increase in the electrical conductivity of the solution mainly for the lowest levels of affluent salinity. The ΔEC in HSSF-CW grown with Vetiver and Tifton 85 grasses were 90.20 and 27.13 mS cm, respectively. Meteorological variables maximize the effect of the vegetative development in ΔEC of the solution. The WUE values of Vetiver and Tifton 85 grasses were 1.77 and 4.18 g kg, respectively. Thus plants with high water use efficiency such as Tifton 85 is indicated for HSSF-CW in which the effluents are used in the fertigation of agricultural crops.
在水资源短缺的地区，将人工湿地出水回用于灌溉施肥是一种很有前景的做法。因此，本研究旨在评估香根草（Chrysopogon zizanioides）和梯牧草（Cynodon sp.）的种植对水平潜流人工湿地（HSSF-CW）多孔介质饱和溶液盐分的影响。这些草被种植在 HSSF-CW 中，并在六个月内接受不同水平的盐分处理。评估了作物的蒸散量、生物量生产力、处理下溶液中电导率的变化（ΔEC）和这些草的水分利用效率（WUE）。在 HSSF-CW 中种植香根草和梯牧草，主要在富营养盐的最低水平下增加了溶液的电导率。在香根草和梯牧草生长的 HSSF-CW 中，ΔEC 分别为 90.20 和 27.13 mS cm。气象变量最大限度地提高了植物在溶液中电导率的生长效应。香根草和梯牧草的 WUE 值分别为 1.77 和 4.18 g kg。因此，像梯牧草这样具有高水分利用效率的植物被推荐用于 HSSF-CW，其中废水被用于农业作物的灌溉施肥。
