Page 214 - Life & Land Use on the Bahrain Islands (Curtis E Larsen)

-190-

with regard to agriculture and nonurban settlement. His appraisal of the
Mesopotamian agriculture system during the third millennium B.C. provides a
possible estimate for maximum agricultural productivity. At that time, crop yields
were great enough to create reliable surpluses.
Given an adequate water supply, suitable soils could produce agricultural
surpluses large enough to provide an accumulation of capital, the growth of
nonagricultural classes, and the generation of a highly complex society. A system
of simple hoe cultivation, for example, can produce two or three times the
domestic needs, given sufficient land area. Allan estimates that the general grain
yield for third-millennium Mesopotamia may have been as high as 1200 kg per
hectare. TTiis amount would yield a critical population density of ca. 300 persons
2
per km based upon an allocation of one kilogram of grain per person per day.
Since this quantity is quite high for individual consumption, Allans figures may
include such unknowns as fallow systems which would reduce the total grain yield
accordingly. FAO data assembled by Ehrlich, Ehrlich, and Holden (1973) also
suggest that Allan’s figures are too high. The average population density for Asia
as a whole only amounts to 172 persons/km2 of arable land. The data necessary to
derive critical population densities based on modern agricultural yields for Bahrain
are not wholly applicable. Population growth has been so rapid over the past
several decades, that modern data yield only exaggerated urban densities with
little relation to preindustrial agricultural production.
To understand these critical areas of study better, recent research by
Jarman and Webley (1975) from the Adriatic coast of Italy was examined. Ttiese
data come from a totally different climatic and soil region from Bahrain, but they
provide useful estimates on grain yields. In Tavoliere along the Adriatic coast,
grain yields are 2000 kg per hectare for small holdings in good years and as low as
600 in poor years. At an allocation of 1 kg per person per day, these yields would
support between 150 and 500 persons per km2. Jarman and Webley (1975) estimated
800 to 1000 kg per hectare yields for the Roman period, and a minimum average
yield during the Neolithic of 500 kg per hectare. In Allan’s scheme, these
agricultural yields translate into critical population densities of 250 persons per