Biological productivity or primary productivity can be expressed as the harvestable yield in tons per hectare at a specific location for a complete growing season. The original concept is based on the use of a computerised model combining rainfall, evaporation, vegetation and soil characteristics, and was developed under the leadership of Prof. Ronald E. Schulze of the Department of Agricultural Engineering at the University of Natal. Biological productivity gives an indication of the ability of landscapes to facilitate vegetation growth. This can also be viewed as the ability of the land to produce crops or the ability of the natural biomes to produce vegetation essential to sustain game, cattle, sheep or goats. Biological productivity is therefore a very important factor in the quest for sustainable use of the environment and economic activity.

The potential biological productivity per capita is an indication of the potential of a geographic area to support the population of that area. It does not take into account the effects of biomass transfers between different geographic areas or locations.