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Appendix 3. LGP sub-zones by country and thermal zone: Selected soil constraints, population and land use data

Explanation of column headings

Thermal zones;


MC 1

Warm tropics


MC 2

Moderately cool tropics


MC 3

Cool tropics


MC 7

Warm sub-tropics (summer rainfall)


MC 8

Moderately cool sub-tropics (summer rainfall)


MC 9

Cool sub-tropics (summer rainfall)

Soil constraints (as defined by the FAO):


Slopes

>30% Steeply dissected to mountainous terrain with dominant slopes of more than 30%.


Shallow soils

Mostly Lithosols and other soils with a restriction for deep root penetration or mechanised tillage. Subject to erosion when on steep slopes.


Poor drainage

Mostly gleysols and other soils with water during part of the year or prone to waterlogging. Require drainage for most crops, except rice.


Vertic properties

High content of clay with shrinking and swelling properties. Tillage difficult when topsoils too dry or too moist.

Population density: based on estimated populations for about 1975.

Potential population density: FAO (1982) computed population supporting capacities at three levels of inputs - low (present), or unimproved land use), intermediate, and high (full use of improved productivity and conservation practices). The intermediate estimate is given here, as a guide to the scope for increased density.

Available agricultural land: the total area, minus an allowance for nonagricultural use, usually a function of the size of the population.

Cropland: rainfed plus irrigated cropland.

Rangeland: grazing areas (not including unused land).

na: not available.

* Area figures differ in the FAO sources.

LGP sub-zones


M 1

150-179 growing days


M 2

120-149 growing days


D 1

90-119 growing days


D 2

75-89 growing days.


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