Mak-Mensah Erastus, Obour Peter Bilson, Wang Qi
College of Grassland Science, Gansu Agricultural University, Lanzhou, China.
Department of Geography and Resource Development, University of Ghana, Accra, Ghana.
PeerJ. 2021 Aug 17;9:e11904. doi: 10.7717/peerj.11904. eCollection 2021.
In semiarid areas, low productivity of crops has been attributed to lack of appropriate soil moisture conservation practices since droughts and soil erosion are rampant in most areas of this region. Consequently, ridge-furrow rainwater harvesting is widely used in these regions across the globe. Despite ridge-furrow being widely practiced, tied-ridge-furrow has not been extensively adopted by small-scale farmers in semi-arid regions. Consequently, the effectiveness of tied-ridge-furrow as a viable method of increasing crop yield has received less attention.
For large-scale implementation, a detailed assessment of how ridge furrow, tied-ridge-furrow with fertilizer, tied-ridge-furrow with mulching and tied-ridge-furrow without mulching or fertilizer influence crop yield in different agro-environments under varying climatic conditions is needed. This study used the PRISMA guidelines to determine the impact of tied-ridge-furrow rainwater harvesting technique with mulching or fertilizer on sorghum () and pearl millet () grain yields.
Sorghum grain yield increased by 17% greater in tied-ridge-furrow without mulching or fertilizer in comparison to flat planting. This may be due to increase in soil organic carbon in the region (9 g kg). Grain yield of millet significantly increased by 20-40% in Africa from 18 study observations in tied-ridge-furrow with fertilizer application as compared to tied-ridge-furrow without mulching or fertilizer treatments. This might be due to the significant increase in total nitrogen by 13-42% in the soil at <50 mg kg quantity which had an effect size of 469.14 [65.60, 872.67]. In terms of soil texture, grain yield of millet and sorghum significantly increased in heavy textured soils (clay loam, silt clay, and clay soils) with an effect size of 469.14 [65.60, 872.67] compared to light and medium-textured soils of zero effect sizes. Millet and sorghum grain yields in tied-ridge-furrow with mulching, on the other hand, were not significantly different from those in flat planting. This may be due to the mulching materials used in those tests.
In view of yields of sorghum and millet increased significantly by 32% and 17% in tied-ridge-furrow without mulching or fertilizer treatment compared to flat planting and tied-ridge-furrow with fertilizer treatment compared with tied-ridge-furrow without mulching or fertilizer treatment, respectively, this study recommend the use of fertilizers in a tied-ridge-furrow system to increase grain yield in semiarid areas compared to flat planting. Again, the study recommends more research on tied-ridge-furrow systems with other organic mulches and fertilizers in semiarid areas.
在半干旱地区，由于该地区大部分地区干旱和土壤侵蚀猖獗，作物产量低一直归因于缺乏适当的土壤水分保持措施。因此，垄沟集雨在全球这些地区被广泛使用。尽管垄沟法被广泛应用，但半干旱地区的小规模农户尚未广泛采用捆绑垄沟法。因此，捆绑垄沟法作为一种提高作物产量的可行方法的有效性受到的关注较少。
为了大规模实施，需要详细评估垄沟法、施肥的捆绑垄沟法、覆盖的捆绑垄沟法以及不覆盖或不施肥的捆绑垄沟法在不同气候条件下的不同农业环境中如何影响作物产量。本研究使用PRISMA指南来确定覆盖或施肥的捆绑垄沟集雨技术对高粱（）和珍珠粟（）谷物产量的影响。
与平作相比，不覆盖或不施肥的捆绑垄沟法下高粱谷物产量提高了17%。这可能是由于该地区土壤有机碳增加（9克/千克）。在非洲，与不覆盖或不施肥处理的捆绑垄沟法相比，在18项研究观测中，施肥的捆绑垄沟法下粟的谷物产量显著提高了20%-40%。这可能是由于土壤中总氮量显著增加了13%-42%，在<50毫克/千克的数量下，效应大小为469.14[65.60，872.67]。就土壤质地而言，与质地轻和中等的土壤（效应大小为零）相比，重质地土壤（粘壤土、粉质粘土和粘土）中粟和高粱的谷物产量显著增加，效应大小为469.14[65.60，872.67]。另一方面，覆盖的捆绑垄沟法下粟和高粱的谷物产量与平作相比没有显著差异。这可能是由于那些试验中使用的覆盖材料。
鉴于与平作相比，不覆盖或不施肥的捆绑垄沟法下高粱和粟的产量分别显著提高了32%和17%，与不覆盖或不施肥的捆绑垄沟法相比，施肥的捆绑垄沟法下粟的产量也显著提高，本研究建议在半干旱地区的捆绑垄沟系统中使用肥料以提高谷物产量。此外，该研究建议对半干旱地区使用其他有机覆盖物和肥料的捆绑垄沟系统进行更多研究。
