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Soil erosion is the main sustainability issue for farming in the cereal zone of
the WANA region. The impact of the four rotations on soil erosion is

The possible benefits of moisture storage still lingers on as an issue with
many farmers. This chapter shows how moisture storage (if it occurs) cannot justify the use of a long cultivated fallow.

Costs and returns are the major determinants of farmers profits. The cost of production for each rotation is examined both for small and large farmers.

Returns relate to the level of output and price. This chapter looks mainly at

For small farmers with few resources and financial reserves risk is
particularly import. A balance needs to be struck between high profits and

Each rotation has an inherent level of weed control. Other weed control
measures can be applied (see later chapters) but the natural ability of the
rotation to "clean" the land or otherwise is an important part of the decision
making process.

The amount of labour and the time it is used are an important aspect of each rotation.

This chapter looks at the capital requirements for each rotation but machinery is treated separately (see below)

Machinery is a special part of the general capital requirements. It is
particularly difficult for small farmers.

We have assumed that the starting point for most farmers is the growing of a cereal crop. We have examined the conflict between the requirement of the cereal crop and the new crop, new forage or pasture being introduced into the rotation.


Small farmers are resource poor. In this chapter we have selected the aspects of the above comparisons that would be appropriate for small farmers.

This chapter provide a framework for selecting a combination of the four
rotations and other variations.

The Zaghouan 4 rotation is not included in the comparison. It is an innovation from Tunisia that cleverly overcomes many of the problems of medic on small farms.





( Traditional rotation)




Cereal crop sown

Cereal crop sown

Cereal crop sown

Cereal crop sown


Cereal crop grows

Cereal crop grows

Cereal crop grows

Cereal crop grows


Cereal crop matures

Cereal crop matures

Cereal crop matures

Cereal crop matures


Cereal crop harvested
Stubble grazed by livestock

Cereal crop harvested
Stubble grazed by livestock

Cereal crop harvested
Stubble grazed by livestock

Cereal crop harvested
Stubble grazed by livestock


Weeds germinate naturally

Medic regenerates from seed
produced 18 months earlier.
No cultivation of the land required.

Land cultivated and sown to vetch or similar forage legumes.

Land cultivated and sown to grain legume such as lentils or
chick peas.


Weeds grazed. Low stocking rate.

Medic pasture grazed. High stocking rate.

Grazed or more often left for hay.

Grain legumes grow.


Land cultivated for fallow

Medic grazed. Pods produced for future regeneration.

Cut for hay.

Grain legumes mature.


Bare soil vulnerable to erosion.

Pods and stubble grazed.

Stubble grazed.

Grain legumes harvested.

Stubble grazed.


Cereal cycle begins again.

Cereal cycle begins again

Cereal cycle begins again

Cereal cycle begins again

Small farmers have special needs

    So far in this comparison of the major rotations for the cereal zone we have looked at sustainability (mainly soil erosion), costs and returns and resources of labour, capital and farm machinery.

Making a choice between the four main options appears to be incredibly complex. In fact some farming systems experts have referred to it as a "black hole" that is beyond the analysis of their computer programmes.

 By separating out the special needs of small farmers we can resolve many of the problems of choice.

Characteristics of small farmers.

    Small farmers in the WANA region are resource poor.

In particular:-

    * They are unlikely to own a tractor. They will use animal traction or contractors to carry out their cultivation, seeding and harvesting.

    * They have little working capital. They will be reluctant to use their limited working capital or to borrow more funds to pay large fees to contractors.

    * They will avoid risk.

    * They usually have family labour available for shepherding of livestock.

    If we use the Gross Margin analysis (for all its weakness) we find that the Gross Margin for livestock and hence pasture is high.

This is because one of the major costs, the shepherding, is an overhead cost. It is not just an overhead cost but is considerably under-utilised

Expansion of the livestock enterprise will not require any additional shepherds on small farms.

We also find that Gross Margins for cereals and other crops or forages that require annual sowing is low due to the of cost of employing contractors and additional labour.

Choices for small farmers

    * Intensive systems not suitable.

    Small farmers will be reluctant to convert all their traditional cereal-fallow rotation to vetch or grain legumes.

They will need to employ additional contractors for the greatly increased work of cultivating and seeding as well as baling the vetch hay.

The grain legumes may be harvested by hand or machine.

Such a complete conversion would require considerable additional working capital and increased risk.

There is some doubt that these rotations are profitable for small farmers with a complete reliance on contractors.

    * Medic - less cultivation needed

    The medic rotation offers the small farmer the opportunity to reduce the cost of keeping livestock (saving on feed) and to increase animal production.

The medic regenerates unlike vetch and there is no need for increased expenditure on machinery or contractors as far as the medic is concerned. The phosphate fertiliser can be applied by hand on small farms.

The cereal crop will still require contractors but no more than the existing cereal-fallow rotation.

    * The classic medic - cereal rotation as used in Australia is not well suited to the needs of small farmers in the WANA region.

The establishment of the medic pasture from imported seed is expensive.

It costs more than vetch.

It requires new skills in preparing a high standard seed bed.

The seed needs to be sown to a shallow depth. As the seeding machinery currently used is not designed for small seeds at a shallow depth the seeding must be done by hand.

The cereal crop must be sown using shallow cultivation. Deep ploughing will  bury the pods to a depth where they will not regenerate in future seasons.

Contractors may not have the equipment. Weed control requires new skills. Poor weed control will reduce cereal yields.

    * Establishing the medic pasture using pods is a much better idea for small farmers.

They can collect the pods using a simple machine developed by ICARDA.

The cost is low.

The pods can be broadcast by hand over the cereal crop.

No special seed bed for the medic pasture is needed.

Zaghouan 4 Rotation

  This seems to be the best choice for small farmers in the cereal zone of the WANA region.

Table 1

    This shows the mean yield of wheat in some long term rotational trials carried out at the Waite Institute in Adelaide, South Australia. Adelaide has a Mediterranean climate very similar to Tunis in Tunisia. It represents the better rainfall part of the cereal zone (>500 mm).

This may account for the length of time for some exploitative rotation to decline.

There was not attempt to measure pasture production in these trials.



Mean yield of wheat in Kg per ha.

Period 1926 to 1951

Period 1952 to 1983

Continuous wheat
Wheat - grain legume (peas)
Wheat - legume pasture - legume pasture (3 years)
Not included
Wheat - legume pasture - legume pasture - legume pasture/fallow (4 years)
(Zaghouan 4 rotation except sub clover used instead of medic) 
Not included

There was no wheat-medic rotation included in these trials. They were conducted at the Waite Institute in the foothills of the Adelaide Hills. The acid soil is better suited to sub clover. Sub clover is difficult to manage in a classic two year rotation. It has lower levels of hard seed and the carry-over from one pasture phase to the next can be poor (there are now cultivars available with more hard seed). The researchers believed that a two-year rotation which required the reseeding of the pasture each second year was too expensive to be a practical. Of course the three year rotation could be practised with medic and there would be no need to reseed the medic as there would be an excellent carry over of hard seed.

* Some important points

    + The highest yield for cereals in the whole trial was achieved using the Zaghouan 4 rotation. These results confirm our claim that a small farmer in the WANA region can produce almost as much wheat from a single cereal crop every 4 years as produced under the cereal-fallow rotation (see below).

Table 2

Zaghouan 4 Rotation.

Traditional cereal - fallow

Three year rotation.

Two years legume pasture. One year legume pasture/ fallow. One year cereal.

During exhaustion phase 1952 to 1983.

Two years legume pasture. One year cereal. No fallow.

Yield of wheat kg/ha




Area of wheat on 10 ha farm.

2.5 ha

5 ha

3.33 ha

Output of wheat on a 10 ha farm

6005 kg

7015 kg

6775 kg

Pasture area

5 ha of legume pasture winter, spring and summer.
2.5 ha for winter only.

5 ha of sparse weeds for winter only.

6.66 ha of legume pasture for winter, spring and summer.

Pasture output.

This can only be estimated because the trials were conducted in an era when wheat was king and the main purpose of the pasture was to provide nitrogen.

5 ha @ 1400 grazing days per ha.= 7000 grazing days

2.5 ha @ 600 grazing days per ha = 1500 grazing days

Total = 8500 grazing days.

5 ha @ 250 grazing days per ha. = 1250 grazing days

6.66 ha @ 1400 grazing days per ha = 9324 grazing days


Cost of cereals low due to small area. Good yields due to good weed control and high soil fertility.
Good production of livestock.
Some opportunity cost from 2.5 ha of fallow.

Total output of cereals high but large area means that costs are high and profit possibly less than for other rotations. Virtually no livestock production.

High output of cereals and high output of pasture for livestock. Theoretically may be the best rotation in the trial but poor weed control could be a problem on farms. The yield would fall.

Advantages for the small farmer

    * High livestock output.

    The Zaghouan 4 rotation provides a great deal of medic pasture for livestock.

There are (in the above example) 5 ha all the year and an additional 2.5 ha for the critical autumn and winter period. 

While the 2.5 ha is fallowed in the spring it will produce a significant amount of feed in autumn and winter.

    * Profitable cereals.

    The Zaghouan 4 rotation in the above long-term trial of 30 years produced the highest cereal yield.

The small farmer requires high yields because he has a high cost of production being dependent on contractors.

The total production of cereals from the farm is slightly lower than the cereal-fallow rotation but the profit is considerably more. Costs relate in the main to area. Half the area will cost roughly half as much to produce.

    For example, if the direct costs of growing cereals were equivalent to 700 kg/ha of wheat the cereal-fallow rotation would produce a Gross Margin equivalent to 3500 kg of wheat over the 5 ha sown in the above example - that is about half the return would go in direct costs and the remaining half (the Gross Margin) would go towards overheads and profit.

    Using the same assumption of 700 kg/ha of wheat as the direct cost, Zaghouan 4 rotation would produce a Gross Margin of 4250 kg. for the 2.5 ha sown or a third more than the cereal-fallow rotation.

    In lower rainfall zones where the yield potential is less the contrast becomes even greater as costs are not reduced in proportion to the yield. This is shown in Table 3 below.

Table 3

    Gross Margins (expressed as equivalent of kg of cereals) for the two rotation with some yield reductions. We have assumed the direct costs (cultivation, sowing, seed and fertiliser and harvesting) remain the same.

Yield reduction from average

Cereal- fallow rotation. Gross Margin expressed in equivalent amount of wheat

Zaghouan 4 rotation. Gross margin expressed in equivalent amount of wheat

Advantage of Zaghouan over traditional fallow - wheat

Average yield

3500 kg

4250 kg


10% reduction

2800 kg

3650 kg


20% reduction

2100 kg

3050 kg


30% reduction

1400 kg

2450 kg


    * Profits even greater.

    The above trials conducted at the Waite Institute perhaps understate the yield advantage for the Zaghouan 4 rotation.

There is no doubt that the cereal-fallow rotation is exploitative and yields will continue to fall and erosion will increase.

The yield difference between to two rotations will increase over time.

The cereal-fallow rotation provides virtually nothing in terms of winter feed except the sparse cover of weeds on the fallow land.

Farmers are often reluctant to cultivate these weeds at the appropriate time in the spring because of the shortage of feed for their livestock.

On real farms the fallow is likely to be a more effective means of weed control on the Zaghouan 4 rotation as the farmer is not under the same pressure to fallow late. There are another 5 ha of medic pasture growing strongly in the warm, long, spring days. The farmer can easily sacrifice 2.5 ha of pasture for the sake of a good fallow and good cereal crop in the following year.

    In the autumn the farmer has only 2.5 ha to sow instead of 5 ha. While experimental centres have ample machinery and can sow all their plots on the same day the farmer cannot. Double the area to sow will mean some delays in sowing and this will reduce yields for the cereal-fallow rotation.

    A similar situation occurs at harvest time where a smaller area can be harvested more easily at the optimum time.

    * Less risk

    The easiest way to reduce risk is to reduce costs. In the above example the farmer will outlay the equivalent of 3500 kg of cereal in direct costs for the cereal-fallow rotation but only 1750 kg of cereal equivalent for the Zaghouan 4 rotation.

If there is a total failure of the crop due to drought the farmer's loss will be only half. This assumes that the cost are equal on a per ha basis. In fact the farmer will not use any nitrogen fertiliser for the Zaghouan rotation and will need some for the cereal-fallow.

    * Existing machinery can be used.

    One of the disadvantages of the classic medic - cereal rotation (as used in Australia) for the small farmer is that he must use shallow cultivation otherwise the medic pods will be buried too deep. They will not regenerate in future years.

With the Zaghouan 4 rotation the farmer is not dependent on regeneration. The medic is re-sown with pods.

Deep ploughing can be used. We do not recommend deep ploughing as it is expensive and unnecessary but a small farmer using contractors may have no alternative.

    * Hay production.

    In "Hay production"we point out that hay production can weaken a medic pasture by removing the pods at the critical time in spring. The Zaghouan 4 rotation overcomes this problem.

    Year 1,  Medic regenerates from pods that were hand sown over the previous cereal crop.

    Year 2  Medic regenerates from pods produced the previous year. The pasture can be cut for hay in the spring. This may cause pod production to fail.

    Year 3 Medic regenerates. If pod production in Year 2 failed there are still pods left from Year 1. Medic is fallowed in the spring. No pod production.

    Year 4 Cereal crop sown on fallow. Pods broadcast over cereals.

    * Low investment.

    The critical aspect of the Zaghouan 4 rotation is the supply of pods. Farmers can harvest these with a simple machine developed by ICARDA. It is not expensive.

The cost can be reduced even further by sharing the machine.

Harvesting the medic pods takes place over many months in summer. A single pod harvester could be shared among many farmers.

    * Flexible response to seasonal rainfall.

    Variable rainfall is one of the great problems in the cereal zone which we will discuss later in more detail.(Decision time in autumn).

Yield potential is therefore variable. Yield is an important part of the Gross Margin (see Table 3 above) but even when it is obvious to the farmer that the yield potential is low there is little he can do to change his farming system at the last moment.

All rotations that include fallow are inflexible to some degree. The fallow is prepared in the spring. It cannot be undone in the autumn if rainfall is low.

The vetch and the grain legume rotations are equally inflexible even without fallow. If these crops or forages are not sown the farmer has nothing.

 The flexibly in the Zaghouan 4 rotation comes from the medic phase. In a good season when there is an excess of grazing some of the medic can be cut for hay which is sold or used as a drought reserve.

The fallow phase of the Zaghouan 4 rotation is inflexible in the sense that the fallow prepared in the spring cannot be undone in the autumn. The Zaghouan fallow will however grow a good medic pasture if shallow cultivation has been used. It autumn rains fail the farmer will have lost money on the preparation of the fallow but will recoup something from the pasture if there are late rains.

What about large farmers?

    If the Zaghouan 4 rotation has all these advantages why is it not suitable for large farmers? The problem for large farmers is the hand harvesting of pods and the hand broadcasting over the cereals. These two task could be mechanised but have not been to date.