Mulching materials and wetted soil percentages on zucchini cultivation

ABSTRACT Polyethylene mulch can cause serious problems in the environment. A promising alternative to polyethylene mulch is biodegradable mulch. Therefore, a two-year experiment was carried out with zucchini (Cucurbita pepo L.) during the cropping seasons of 2017 and 2018 in Southeast Brazil to investigate the effects of four soil mulching treatments (white polyethylene mulch: WP, black polyethylene mulch: BP, biodegradable mulch of brown recycled paper: RP and nonmulched: NM) and two wetted soil percentages (50 and 70% of the soil surface) using a randomized block design with five repetitions. The average water consumption of the zucchini was 157 mm in the WP treatment, 155 mm in the BP treatment, 155 mm in the WP treatment and 215 mm in the NM treatment. The yield was higher in the WP (78.1 ton ha-1) and BP (69.1 ton ha-1) treatments than in the RP (66.6 ton ha-1) or NM (52.4 ton ha-1) treatments. The daily thermal amplitude was lowest in the RP treatment (3.6-6.0 °C) and highest in the BP treatment (7.3-9.0 °C). The lower wetted soil percentage (50%) reduced water consumption (by 5-7%) and improved water-use efficiency (by 11%). Weeds, including Cyperus roduntus, were more efficiently controlled in the RP treatment than in the WP and BP treatments. In general, compared to the nonmulched treatment, mulches were effective in reducing weed infestation (95%), increasing yield (36%) and improving water-use efficiency (94%). RP, as an alternative to polyethylene mulch, can save water and control weeds in zucchini crops. These results represent useful information that extends the mulching options for technicians and farmers.摘要 聚乙烯地膜（Polyethylene mulch）会对自然环境造成严重负担。可降解地膜（biodegradable mulch）是极具应用潜力的聚乙烯地膜替代方案。为此，研究团队于2017年与2018年作物生长季在巴西东南部开展了为期两年的西葫芦（Cucurbita pepo L.）种植试验，以探究4种土壤覆盖处理[白色聚乙烯地膜（WP）、黑色聚乙烯地膜（BP）、棕色再生纸可降解地膜（RP）及无地膜覆盖（NM）]与2个土壤湿润表面积占比（50%与70%）的影响，试验采用随机区组设计（randomized block design），设置5次重复。 西葫芦的平均耗水量在白色聚乙烯地膜处理组为157 mm，黑色聚乙烯地膜处理组为155 mm，白色聚乙烯地膜处理组为155 mm，无地膜覆盖处理组为215 mm。白色聚乙烯地膜组（78.1 吨·公顷⁻¹）与黑色聚乙烯地膜组（69.1 吨·公顷⁻¹）的产量高于棕色再生纸可降解地膜组（66.6 吨·公顷⁻¹）与无地膜覆盖组（52.4 吨·公顷⁻¹）。日热振幅以棕色再生纸可降解地膜处理组最低（3.6~6.0 ℃），黑色聚乙烯地膜处理组最高（7.3~9.0 ℃）。较低的土壤湿润占比（50%）可降低耗水量（降幅5%~7%）并提升水分利用效率（提升11%）。包括香附子（Cyperus roduntus）在内的杂草在棕色再生纸可降解地膜处理中的防控效果优于白色与黑色聚乙烯地膜处理组。总体而言，相较于无地膜覆盖处理，地膜覆盖可有效降低杂草滋生量（95%）、提升产量（36%）并改善水分利用效率（94%）。棕色再生纸可降解地膜作为聚乙烯地膜的替代方案，可在西葫芦种植中实现节水与杂草防控。本研究结果可为技术人员与种植户拓展地膜覆盖选择提供实用参考。