Linking soil erosion to on-site financial cost: lessons from watersheds in the Blue Nile basin
Linking soil erosion to on-site financial cost: lessons from watersheds in the Blue Nile basin
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DOI：
10.5194/se-6-765-2015
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发表时间：
2015-01-01
期刊：
影响因子：
3.4
通讯作者：
Taye, G.
中科院分区：
文献类型：
--
作者：
Erkossa, T.;Wudneh, A.;Taye, G.
这项研究是在青尼罗河流域埃塞俄比亚部分的三个流域（Dapo、Meja和Mizewa）进行的，目的是利用生产力变化方法估计土壤侵蚀的现场成本，其中分析了由于植物养分随沉积物和径流流失而损失造成的作物产量减少。为此，在2011年主雨季期间，在每个流域的两到三个子流域的出口进行了径流测量和采样。测定了径流泥沙含量、径流泥沙中N、P含量。根据最近的农业研究中心获得的数据，为这两种植物养分开发了作物响应函数。响应函数被用来估计作物产量减少的损失N和P假设没有通过施肥补偿的结果。结果表明，产量显著减少，并给农民造成经济损失。仅考虑玉米（Zea mays）的谷物产量，由于氮和磷的损失，Dapo的农民每年分别损失约220公顷（-1）和150公顷（-1）。考虑到作物残渣的重要性，包括作为饲料的重要性，损失可能更大。研究表明，除了土地质量长期恶化外，农民每年遭受的经济损失也很大。因此，需要鼓励在农业上采取在生物物理和社会经济方面适合地貌景观及其他地区的水土保持措施。
The study was conducted in three watersheds (Dapo, Meja and Mizewa) in the Ethiopian part of the Blue Nile Basin to estimate the on-site cost of soil erosion using the productivity change approach, in which crop yield reduction due to plant nutrients lost with the sediment and runoff has been analysed. For this purpose, runoff measurement and sampling was conducted during the main rainy season of 2011 at the outlet of two to three sub-watersheds in each watershed. The sediment concentration of the runoff, and N and P contents in runoff and sediment were determined. Crop response functions were developed for the two plant nutrients based on data obtained from the nearest Agricultural Research Centres. The response functions were used to estimate crop yield reduction as a result of the lost N and P assuming there is no compensation through fertilization. The results show a significant yield reduction and resultant financial loss to the farmers. Considering only grain yield of maize (Zea mays), farmers at Dapo annually lose about USD 220 ha(-1) and 150 ha(-1) due to the loss of N and P, respectively. In view of the importance of the crop residues, including as feed, the loss can be even greater. The study demonstrated that in addition to the long-term deterioration of land quality, the annual financial loss suffered by farmers is substantial. Therefore, on farm soil and water conservation measures that are suitable in biophysical and socio-economic terms in the landscapes and beyond need to be encouraged.