An overview of development


Farming zones in WANA

Overview of the zone





  ABOVE 500 mm


     500 mm  to 200 mm 

    Medic overview

Deep ploughing overview

Farmers' Guide to cereals and pasture

Farmer training kits

This is a major section of the site

What cultivar?

 How does your medic grow?


  250 mm  to 150 mm


 Tenure and grazing management


Below 200  mm

Rangeland overview

Action plan for flockowners

Water harvesting

What is the marginal zone?

      Rainfall and Land Use

    The Marginal Zone (also called the Agro-pastoral Zone) is the area between the Rangeland and the Cereal Zone that is cultivated.

We have resisted the temptation to define the various zones in the WANA region in purely rainfall and length of growing season.

It is easy to define the Rangeland as less than 200 mm.

The Cereal Zone is 200 mm to 500 mm and the High Rainfall Zone is above 500 mm.

The reality is more complex as the zones are defined by land use as well as rainfall (of course the two interact).

The Rangeland is not just the area below about 200 mm but used for extensive grazing.

    The Marginal Zone is the fringe of the Rangeland and the Cereal Zone that is cultivated for cereals.

In rainfall terms it is therefore 250 mm to 150 mm. with the cultivation in the lower rainfall parts being in wadi beds and other areas that collect additional moisture.

The cereals are not harvested for grain except in a good season. It is therefore a Cereal Zone without cereal grain.

In most years the cereal crops are grazed by the owner's flock or sold to nomadic flockowners.

The cultivation depends on topography and soils as well as rainfall. The Marginal Zone has expanded over the last 50 years to encroach on the Rangeland.

    A look at the rainfall maps of the WANA region shows that the Marginal Zone is vast. It is larger than the High Rainfall Zone and in many case the Cereal Zone.

What are the problems of the marginal zone?


    The marginal zone is suffering from acute soil erosion caused by both wind and water.

There is a poor vegetative cover of the soil during the winter and none at all for the rest of the year.

The soil is poorly structured due to excessive cultivation and is easily eroded.

The erosion can be directly linked to the excessive cultivation of the land and the severe over grazing.

  Costs and returns.

    The cost of production in the zone is high in relation to returns because the land is cultivated frequently (almost every year) to sow a cereal crop.

There is the cost of the cereal seed as well as the cost of cultivation and sowing.

    Returns are low because the fertility of the soil is so low.

Nitrogen fertilisers are not used and would not be economic in an area with such low and variable rainfall. Without nitrogen fertiliser or legumes the soil is only producing a small fraction of its potential.

How did the marginal zone become so degraded? 

    The Rangeland was in balance with the livestock 50 years ago due to the large scale death of animals during periods of drought.

The Marginal Zone was  also in balance.

The degradation of the zone is due to the introduction of tractors and cheap fuel over the last 50 years.

    When animal traction was used there was a simple equation:

  Energy produced by the cereal crop

Equal or greater than

Energy needed by the animals and humans producing the crop.

    Translated to the Marginal Zone frequent crops soon exhausted the soil fertility.

The yields were low.

The energy required by animals and humans to grow and harvest the crop was less than that needed for survival.

Cultivation was discontinued.

The land was left to grow pasture and for some fertility to return.

It was not possible to grow low yielding crop after low yielding crop without starving.

The Marginal Zone survived without severe erosion for thousands of years.

    Tractors have changed that balance.

More energy can be put into the system through large tractors than comes out.

The system turns cheap tractor fuel into a crop or grazing.

More energy can go into the production process than comes out.

The conversion is not efficient but provided there is a profit - even a small one - it continues.

The last 50 years has cause more degradation to the Marginal Zone than the previous millennia.

Cultivation and tenure 

Cultivation plays an important role in providing tenure rights.

There is a tradition that flockowners do not graze growing crops.

Nomadic flockowners often sow cereal crops as they move out into the rangeland during the winter.

Other flockowners would pass by (see grazing paths) but traditionally they respected the growing crop.

It was not grazed in spite of the fact that the people who sowed it might be hundreds of kilometres further out in the rangeland.

When the first group of flockowners returned in spring they harvested the crop and grazed the stubble.

Any stubble not grazed became a common resource to be grazed by all flocks passing that way on the grazing path.

The farmers of the Marginal Zone are often nomadic flockowners who have expanded their cultivation to achieve tenure over the land using this ancient tradition as the mechanism.

Some have settled and are no longer truly nomadic.

They have used the traditional respected for cultivated land and growing cereals to obtain a de facto annual tenure.

As their tenure is based on the tradition respect for cultivation they are in danger of losing it if they fail to cultivate the land.

They are caught in a trap.

Cultivation and sowing cereals is a wasteful and costly means of producing a pasture.

Annual cultivation causes more damage even than the cereal fallow rotation.

Unless they cultivate the land they are in danger of losing their tenure.

Once the cultivator has embarked on this system it is difficult to break free.

Sowing cereals into degraded and infertile soil is a poor means of producing pasture but doing nothing produces even less in the short term.

Breaking free

    Like the Rangeland the solution to the problem lies in a development program that simultaneously attacks the problems of tenure (see  Marginal zone tenure )  and the technical and management problems of the pasture.