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40 2019 ND-CP 413905
| Agro-ecological zoning
Agro-ecological Zoning (AEZ) is a quantitative assessment of plant adaptability to a certain region. It is an expanded and quantified methodology based on Framework concepts. Agro-ecological zones refer to a division of the earth’s surface into homogeneous areas with respect to the physical factors that are most important to plant production. Continental-scale efforts were intended to obtain a first approximation of the production potential of the world’s land resources; national-scale AEZ maps and reports provide the physical data base necessary for planning future agricultural development and zoning for rural development policies. A continental assessment was carried out for Africa, Southeast and Southwest Asia and Central and South America (FAO 1978-1981). The first country-scale study of its kind was done for Kenya (Kassam et al., 1991). A key concept is the length of growing period, which is based on rainfall and temperature regimes. The growing period forms the basis for a quantitative climatic classification for each chosen crop, assuming rain-fed agriculture. An agro-climatic adaptability classification matches each crop with climate and soil resources. The soil and landscape requirements comprise both internal soil properties and external site qualities, not contemplating land modifications. A crop production cost is provided by soil and climatic zone, and is aimed at judging whether yields exceed costs. The ultimate output of an AEZ is a map of suitability classes S1, S2, S3, N1 and N2, based on predicted relative biomass production, for two technology levels (high and low inputs), which define a general land utilization type. The FAO AEZ is based on the Framework principles and uses the Framework definitions of suitability based on relative yield. Extensions and updates to the original AEZ methodology are discussed in Annex 3, section Modelling. tải về 0.57 Mb. Chia sẻ với bạn bè của bạn:
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