The impact of organic farming on food security in a regional and global perspective
The impact of organic farming on food security in a regional and global perspective
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从区域和全球角度看有机农业对粮食安全的影响
DOI：
10.1079/9781845930783.0277
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发表时间：
2006
影响因子：
30.7
通讯作者：
M. T. Knudsen
中科院分区：
文献类型：
--
作者：
N. Halberg;T. Sulser;H. H. Jensen;M. Rosegrant;M. T. Knudsen
发展中国家有机农业和农业生态农业方法的推广引发了一场辩论，即大规模采用有机农业会增加还是减少全球粮食安全。然而，这将取决于一些社会经济因素，以及有机耕作与传统耕作系统的相对产量水平。相对产量也取决于一些农业生态因素和转换前耕作制度的特点。
在集约化高投入农业地区，转换为有机农业通常会导致与豆科饲料作物相结合的作物轮作中每公顷作物产量减少20 - 45%。在许多农业系统投入低的地区，农民很少有动力或机会使用化肥和农药，采用农业生态原则后，产量可能会增加。
虽然目前的粮食生产理论上足以满足全球人口的能量和蛋白质需求，但仍有7.4亿多粮食不安全人口，其中大多数生活在南亚和撒哈拉以南非洲。如果改变目前的政策，这一数字在今后20年内只会减少。粮食政策模型IMPACT被用来预测欧洲/北美（E/NA）和撒哈拉以南非洲大规模转向OF对粮食安全可能产生的影响。结果表明，转换约50%的E/NA农业面积将对世界（非肉类）农产品价格产生6 - 10%的影响，假设转换后的OF产量比传统作物产量低35%，产量增长率比传统作物产量高50%。对撒哈拉以南非洲粮食安全的间接影响将是非常小的，从案例研究到情景的经验，撒哈拉以南非洲50%的农业面积转换的结果是提高自给自足和减少该地区的粮食净进口。假设大多数有机作物的相对产量高于现有的低投入农业，如果能力建设和研究支持非认证的有机农业，则有可能改善撒哈拉以南非洲的当地粮食安全。然而，还需要更多的知识来证实这些未经认证的有机农业的乐观结果适用于撒哈拉以南非洲和其他低投入农业地区的大面积地区。
The spread of organic and agro-ecological farming (OF) methods in developing countries has raised a debate whether a large scale adoption of OF will increase or decrease global food security. This will however depend on a number of socio-economic factors together with the relative yield levels of OF versus conventional farming systems. Relative yields again depend on a number of agro ecological factors and the characteristics of farming systems before conversion.
In areas with intensive high-input agriculture, conversion to OF will most often lead to a reduction in crop yields per ha by 20-45 % in crop rotations integrated with leguminous forage crops. In many areas with low input agricultural systems farmers have little incentive or access to use chemical fertiliser and pesticides, and yields may increase when agro ecological principles are introduced.
While present food production in theory is sufficient to cover the energy and protein needs of the global population there are still more than 740 million food insecure people, the majority of whom live in South Asia and Africa South of Sahara (SSA). This number will only decrease over the next 20 years if the present policies are changed. The food policy model IMPACT was used to project possible effects on food security of a large scale conversion to OF in Europe/North America (E/NA) and SSA. Results indicate that a conversion of approximately 50 % of E/NA agricultural area will have a 6-10 % impact on world prices on (non-meat) agricultural commodities under the assumptions of 35 % lower OF yields after conversion and 50 % higher yield growth rates compared with conventional crop yields. The indirect effect on food security in SSA would be very small up scaling experiences from case studies into scenarios for conversion of 50 % of agricultural area in SSA results in increased self-sufficiency and decreased net food import to the region. Given the assumption of higher relative yields in most organic crops compared with existing low input agriculture, there is potential for improving local food security in SSA if non-certified OF is supported by capacity building and research. More knowledge is needed, however, to confirm that these optimistic results of non-certified OF apply to large areas in SSA and other regions with low input agriculture.