《Agricultural Water Management》刊登“长期的水土保持对农业生产率的影响：以埃塞俄比亚Anjenie流域为例”

作者： Enyew Adgo, Akalu Teshome, Bancy Mati

刊物：《Agricultural Water Management》,2013年1月，第117卷，页码：55-61.

关键词：梯田；农业生产力；利益率；投资回报率；家庭劳动力

摘要：在过去的三十年中，为了控制土地退化，提高土地生产力，非洲的东部和南部的各个地区实施了许多水土保持工程，特别是在20世纪80年代提出了“流域方法”的方案。在埃塞俄比亚，许多水土保持工程是在1974年的严重干旱之后实施的。为了追踪这些措施的长期影响，本文对埃塞俄比亚的Anjenie流域进行了研究，评估该流域的梯田和草带。这些梯田和草带是建于1984年的试点项目，但在25年之后它仍然发挥着作用。研究的资料来源于政府记录、实地观察和对60位农民的问卷调查。一半的受访者在流域从前的项目区（实施了水土保持技术）有梯田农场，其余的人在梯田区之外（未实施水土保持技术）。评估的作物包括画眉草，大麦和玉米。成本效益分析用于确定梯田是否带来经济效益，包括毛利和纯利价值、劳动回报、水资源利用率和对贫困的影响。结果表明：水土保持提高了作物产量。生产画眉草，大麦，玉米的梯田的平均收益率分别为0.95吨/公顷（对照组0.49），1.86吨/公顷（对照组0.61）和1.73吨/公顷（对照组0.77）。净效益显著提高的梯田分别是，每年每公顷画眉草20.9美元（对照组-112美元），大麦185美元（对照组-41美元 ）和玉米-34.5美元（对照组-101美元）。生长在梯田地块的大麦，画眉草和玉米对家庭劳动的回报率分别为2.33，1.01和0.739美元人/日，而没有生长在梯田地块的分别是0.44、0.27和0.16。若使用10％的折现率，则在梯田种植的大麦生产的平均净现值（NPV）在50年间约为1542美元。此外，平均财务内部收益率（FIRR）为301％。其他长期影响梯田的因素包括为了节约用水，农民在梯田上种植的玉米。与没有梯田的农场不同。目前，农民每年在两个作物季节里都在梯田种植大麦。家庭收入和粮食安全已得到改善，土壤侵蚀大幅减少。许多农民已采取水土保持试点项目下的梯田使原来的面积增加一倍，从而改善和保护该流域的环境。

Impacts of long-term soil and water conservation on agricultural productivity: The case of Anjenie watershed, Ethiopia

Authors: Enyew Adgo, Akalu Teshome, Bancy Mati

Journal: Agricultural Water Management, Volume 117, 31 January 2013, Pages 55–61

Key words: Terrace; Crop productivity; Profitability; Return to investment; Family labour

Abstract: Over the last three decades, many soil and water conservation projects have been implemented in various parts of eastern and southern Africa to control land degradation, and improve land productivity, especially under ‘catchment approach’ initiatives of the 1980s. In Ethiopia, many of these soil conservation projects were implemented following the severe drought of 1974. To capture long-term impacts of these initiatives, a study was conducted in Anjenie Watershed of Ethiopia, assessing fanya juu terraces and grass strips constructed in a pilot project in 1984, and which are still functional 25 years later. Data were collected from government records, field observations and questionnaire surveys administered to 60 farmers. Half of the respondent had terraced farms in the watershed former project area (with technology) and the rest were outside the terraced area (without technology). The crops assessed were teff, barley and maize. Cost–benefit analyses were used to determine the economic benefits with and without terraces, including gross and net profit values, returns on labour, water productivity and impacts on poverty.

The results indicated that soil and water conservation had improved crop productivity. The average yields on terraced fields for teff, barley and maize were 0.95 t ha⁻¹ (control 0.49), 1.86 t ha⁻¹ (control 0.61), and 1.73 t ha⁻¹ (control 0.77), respectively. The net benefit was significantly higher on terraced fields, recording US$ 20.9 (US$ −112 control) for teff, US$ 185 (US$ −41 control) for barley and US$ −34.5 (US$ −101 control) ha⁻¹ yr⁻¹ for maize, respectively. The returns on family labour were 2.33, 1.01 and 0.739 US$ man-day⁻¹ for barley, teff and maize grown on terraced plots compared to US$ 0.44, 0.27 and 0.16 man-day⁻¹ for without, respectively. Using a discount rate of 10%, the average net present value (NPV) of barley production with terrace was found to be about US$ 1542 over a period of 50 years. In addition, the average financial internal rate of return (FIRR) was 301%. Other long-term impacts of terracing included farmers’ growing of maize on terraced fields as a result of water conservation. Currently, farmers also grow barley on terraced fields for two crop seasons per year unlike the experiences on farms without terraces. Household incomes and food security had improved and soil erosion drastically reduced. Many farmers had adopted terracing doubling the original area under the soil conservation pilot project and consequently improving environmental conservation in the watershed.

 原文链接：http://www.sciencedirect.com/science/article/pii/S0378377412002831