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