20. Perhaps carrying capacity as perceived by planners is too conservative. Several workers have questioned the 'standard' planning parameters used for estimating carrying capacity in the communal lands, suggesting that higher cattle populations may be economically justified without reaching the ecological limits of carrying capacity (for example: Sandford, 1982; Jarvis and Erickson, 1986; Scoones, 1987). Such questions merit urgent attention in the Zambezi Valley if the gap can be narrowed between the planned herd size and the number of livestock desired by the local people.
21. Carrying capacity could possibly be increased above present levels by the intensive production of livestock feed. Sandford (1982, page 73) has advocated this approach as generally a more appropriate policy than attempting to limit livestock numbers. Improved range management, harvesting and conservation of crop residues, and production of fodder crops could all contribute to increased carrying capacity. However, the potential impact of such measures (in particular production of fodder crops) is probably limited in the semi-arid Zambezi Valley compared with higher-rainfall areas elsewhere in Zimbabwe.
22. Even if carrying capacities can be established at levels higher than presently assessed, a tendency towards overstocking still appears likely, at least in some parts of the Valley. This may be related to the minimum herd size perceived by individual farmers as necessary in order to be self-sufficient in draught power: human population density can simply exceed the level at which there are adequate grazing resources for each household to maintain a 'self-sufficient' herd. For example, in the Gutsa communal land area in the Zambezi Valley (under the auspices of the MZVRDP), the planned settlement density for the immediate future is 5 households per sq km. The officially recommended stocking rate for grazing areas in Gutsa is in the order of 10 LUs (rather less than 20 cattle) per sq km. This allows for an average of some two livestock units (three or four cattle) per household compared with a herd size in the order of 10 cattle per household which has been suggested as appropriate for subsistence (see for example Sandford, 1982: p. 103).
23. The problem will become worse as the population of the Zambezi Valley increases in the future through natural growth, so that there will be an increasing number of households each wanting to own cattle. Population growth will also bring increasing pressure to put some of the presently designated grazing land under arable farming.
