Import of Plant Nutrients

Background A common practice is that animals graze during the day time on communal pastures and pass the night in a kraal on the farm. About half the amount of the daily urine and manure excretion by the animals is so deposed in the kraal. The amount largely depends on the number of animals on the farm and the availability of communal pastures in the areas surrounding the farm. | Background Policy Pressures and Policy Options Technology Options

The livestock / cropland ratio required to sustain a moderate level of crop production in this systems is estimated at about 4 Tropical Livestock Units per ha. of cropland. In practice this required number can be more or less depending on basic soil fertility, climatic conditions, type of crop cultivated, acceptable production level etc.

Driving Force | Pressures for Change | Result
Increase of land under cultivation | Decreasing area for grazing Increasing demand for manure to sustain crop production | More livestock grazing outside cropping zone and more animals on seasonal migration for longer periods, resulting in less manure for crop cultivation. Improved manure management Use of inorganic fertilisers
Increase of competition on remaining pasture land | Increase consumption of poor quality feed Crop residues have become relatively more important Lower production levels per animal | Change of production systems towards mixed farming crop residues, cut and carry. Local rules and regulations to protect and control use of communal pastures. Increase in diversity of farming systems Increase of farms with little or no livestock. Increase of land degradation through crop cultivation.

Remaining communal pastures continue to play a supportive role to crop cultivation through transport of plant nutrients and organic matter by livestock from these areas to cropland. However the potential of this practice to cope with an increasing demand for manure is declining as a result of an expansion of crop cultivation on former pasture land. Meanwhile the competition with livestock from other systems on the remaining communal pastures also increases as these systems are facing the same problem.

Farmers adjust their livestock system according to remaining and alternative feed resources, on their farm, locally and outside the area. It is not in their interest to adjust their systems according to the degree of degradation on communal pastures. Further degradation should be avoided and controlled use be established through local rules and regulations accepted and respected by the users, i.e. in the context of local natural resources management

[Livestock & Environment Toolbox Home]