Performance of organic and synthetic mulches to reduce salinity stress and increase fruit yield of sweet gourd in silty clay loam coastal soils

Abstract Sweet gourd ( Cucurbita moschata ), among the cucurbits, is highly susceptible to salt stress; however, it has high potential for cultivation in the coastal salt-affected vast fallow lands, if managed appropriately. The aim of the experiment was to identify suitable Mulch material which reduces salt stress in crop and increase fruit yield of sweet gourd in saline soils. Seven different organic and synthetic Mulches including rice straw, water hyacinth, jute bag, plastic bag, semi-transparent polythene sheet, blue color polythene sheet and black color polythene sheet, along with a control were tested in the experiment during the Rabi season of 2022–23 and 2023–24 in coastal salt affected region of Bangladesh. All types of mulches increased fruit yield and reduced salinity level compared to the control treatment. Among the synthetic sources, black polythene mulch (24.2 t ha −1 ), while among the organic sources, the rice straw mulch (23.5 t ha −1 ) had the highest fruit yield; whereas control treatment had only 13.8 t ha −1 fruit yield. Organic mulches kept soils cooler (25.0–27.3 °C), whereas synthetic mulches increased soil temperature (28.3–32.8 °C) compare to control (27.9 °C). All the Mulches kept soil moist for longer period; thereby lowering electrical conductivity. Black polythene Mulches had lowest of 0.085% leaf sodium content which was 27.4% lower than the control treatment. Overall, among organic sources rice straw mulch, and among synthetic sources black colour polythene mulch were the most effective in improving fruit yield of sweet gourd and reducing salt stress in saline soils.