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World agriculture towards 2030/2050: the 2012 revision - Fao

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PROOF COPY<br />

Box 4.2 Agro-ecological zone (AEZ) methodology<br />

The AEZ modelling uses detailed agronomic-based knowledge to simulate land resources<br />

availability, assess farm-level management options and estimate crop production potentials. It<br />

employs detailed spatial biophysical and socio-economic datasets to distribute its computations<br />

at fine gridded intervals over <strong>the</strong> entire globe (Fischer et al., 2002). This land-resources<br />

inventory is used to assess, for specified management conditions and levels of inputs, <strong>the</strong><br />

suitability of crops in relation to both rain-fed and irrigated conditions, and to quantify expected<br />

attainable production of cropping activities relevant to specific agro-ecological contexts. The<br />

characterization of land resources includes components of climate, soils, landform, and present<br />

land cover. Crop modelling and environmental matching procedures are used to identify cropspecific<br />

environmental limitations, under various levels of inputs and management conditions.<br />

In summary, <strong>the</strong> AEZ framework contains <strong>the</strong> following basic elements:<br />

• Land resources database, containing geo-referenced climate, soil and terrain data;<br />

• Land Utilization Types (LUT) database of agricultural production systems, describing cropspecific<br />

environmental requirements and adaptability characteristics, including input level<br />

and management;<br />

• Ma<strong>the</strong>matical procedures for matching crop LUT requirements with agro-ecological zones<br />

data and estimating potentially attainable crop yields, by land unit and grid-cell (AEZ<br />

global assessment includes 2.2 million land grid cells at 5′ by 5′ latitude/longitude);<br />

• Assessments of crop suitability and quantification of land productivity.<br />

Source: excerpt from Fischer et al. (2010).<br />

Box 4. 3 Assumed levels of inputs and management<br />

Low-level inputs/traditional management<br />

Under <strong>the</strong> low input, traditional management assumption, <strong>the</strong> farming system is largely subsistence<br />

based and not necessarily market oriented. Production is based on <strong>the</strong> use of traditional cultivars (if<br />

improved cultivars are used, <strong>the</strong>y are treated in <strong>the</strong> same way as local cultivars), labour intensive<br />

techniques, and no application of nutrients, no use of chemicals for pest and disease control and<br />

minimum conservation measures.<br />

Intermediate-level inputs/improved management<br />

Under <strong>the</strong> intermediate input, improved management assumption, <strong>the</strong> farming system is partly<br />

market oriented. Production for subsistence plus commercial sale is a management objective.<br />

Production is based on improved varieties, on manual labour with hand tools and/or animal traction<br />

and some mechanization. It is medium labour intensive, uses some fertilizer application and<br />

chemical pest, disease and weed control, adequate fallows and some conservation measures.<br />

High-level inputs/advanced management<br />

Under <strong>the</strong> high input, advanced management assumption, <strong>the</strong> farming system is mainly market<br />

oriented. Commercial production is a management objective. Production is based on improved<br />

high yielding varieties, is fully mechanized with low labour intensity and uses optimum<br />

applications of nutrients and chemical pest, disease and weed control.<br />

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