Effects of soil and water conservation techniques on crop yield, runoff and soil loss in Sub-Saharan Africa: A review
Effects of soil and water conservation techniques on crop yield, runoff and soil loss in Sub-Saharan Africa: A review
复制标题
撒哈拉以南非洲水土保持技术对作物产量、径流和土壤流失的影响
DOI：
10.1016/j.agwat.2018.05.016
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发表时间：
2018-08
影响因子：
6.7
通讯作者：
Kebede Wolka;J. Mulder;B. Biazin
中科院分区：
文献类型：
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作者：
Kebede Wolka;J. Mulder;B. Biazin
水对土壤的侵蚀是造成非洲土地退化和农业生产力下降的主要原因之一，估计每年造成2.8亿吨作物产量损失。为了扭转这个问题，各种本地和最近推出的跨坡障水土保持（CSB-SWC）技术已经实施。这些措施包括范亚juu 1，土堤，石堤，梯田，植物屏障和系埂。在这篇综述中，我们分析和综合各种研究的结果，集中在径流，土壤流失，土壤性质，作物产量和生物量在撒哈拉以南非洲（SSA）的CSB-SWC技术的影响。各种CSB-SWC技术的引入被发现减少径流和土壤流失分别为13-71%和39- 83%。超过80%的科学研究表明，对作物产量的积极影响主要是由于营养和水分的保留。CSB-SWC技术对作物产量的影响因降雨量和坡度而异，大多数CSB-SWC技术在低降雨量地区提高作物产量，在相对平缓的斜坡上，范雅Juu和土堤有效，而在中度陡坡上，绿篱和石堤也有效。然而，整个SSA的研究表明，一些CSB-SWC技术可能有负面的副作用，如内涝。此外，这些技术与占用大量可耕地有关。因此，它们需要适当的设计和实施。在大多数情况下，CSB-SWC技术在经济上是可行的，由于提高作物产量和低劳动力机会成本。然而，建设成本高、土地面积小、土地保有权无保障和短期效益低可能会阻碍执行工作。CSB-SWC的有效性和效益可以通过与其他土地管理技术（如土壤肥力改良剂和保护性耕作）的整合来提高。
Soil erosion by water is one of the main causes of land degradation and reduced agricultural productivity in Africa leading to an estimated annual loss in crop yield of 280 million tons. To reverse this problem, various indigenous and recently introduced cross slope barrier soil and water conservation (CSB-SWC) techniques have been implemented. These includeFanya juu1, soil bunds, stone bunds, bench terraces, vegetative barriers, and tied-ridges. In this review, we analyze and synthesize the results of various studies that focused on the effects of CSB-SWC techniques on runoff, soil loss, soil properties, crop yield, and biomass in Sub-Saharan Africa (SSA). Introduction of various CSB-SWC techniques was found to reduce runoff and soil loss by 13–71% and 39–83%, respectively. More than 80% of the reviewed scientific studies showed a positive effect on crop yield mainly due to retention of nutrients and moisture. The effect of CSB-SWC techniques on crop yield varies with rainfall and slope, with most of the CSB-SWC techniques improving crop yields in low rainfall areas.Fanya juuand soil bunds were effective on relatively gentle slopes while hedgerows and stone bunds were effective even on moderately steep slopes. However, studies across SSA indicate that some CSB-SWC techniques could have negative side effects such as waterlogging. Also, these techniques are associated with the occupation of significant areas of cultivable land. Thus, they require proper design and implementation. In most cases, CSB-SWC techniques are economically feasible, due to improved crop yield and low labor opportunity costs. However, implementation may be hampered by high construction costs, small landholding size, land tenure insecurity, and low short-term benefits. Effectiveness and benefits of CSB-SWC can be improved by their integration with other land management techniques such as soil fertility amendments and conservation tillage.