HIGH RAINFALL ZONE

The pasture option?

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Farming zones in WANA

Overview of the zone

GUIDE  FOR FARMERS AND EXTENSION AGENTS

TECHNICAL BACKUP FOR EXTENSION PROGRAMS

POLICY MAKERS AND PROJECT PLANNERS

 HIGH   RAINFALL  ZONE

  ABOVE 500 mm

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CEREAL  ZONE

     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?

   MARGINAL  ZONE 
   

  250 mm  to 150 mm

 Tenure and grazing management

RANGELAND

Below 200  mm

Rangeland overview

Action plan for flockowners

Water harvesting

 

What is the high rainfall zone?

    The easy, but superficial, answer is that the high rainfall zone is the area with over 500 mm of annual average rainfall. 

As with the cereal zone, the marginal zone and the rangeland we have avoided a definition using these simple rainfall or length of growing period measurements.

The same is true of the high rainfall zone.

The characteristics of the zone are more complex than just rainfall above 500 mm.

The zone is associated with hills and mountains. Steep slopes influence land use.

Throughout the WANA region hills and mountains are responsible for the increase in rainfall - steep slope, altitude and rainfall go together. The farms are usually smaller in the hills and mountains and populations higher.

The farming system changes with increased rainfall and a more diversified range of crops is grown.

The cereal zone is wheat or barley with fallow but the high rainfall zone includes other crops such a oilseeds.

There are also tree crop.

This in not a sudden change but depends on local conditions.

I recall receiving a letter from a high official in the World Bank in Washington when I was Minister of Agriculture telling me that my proposal for the use of the medic - cereal rotation in a part of Morocco was unworkable because the rotation was for the Cereal Zone not the High Rainfall Zone.

The district under discussion had a rainfall of 520 mm which he pointed out meant that it was no longer in the Cereal Zone but the High Rainfall Zone.

 As the rainfall becomes even higher there is also an increase in altitude, slopes become too steep for cultivation. The land is used for grazing and forestry.

The High Rainfall Zone is also important for water collection. Many large dams have been built in the zone over the last few decades.

The water is used for urban centres and for irrigation (outside the scope of this site).

The protection of the catchment from erosion is an important aspect of the management of the zone.

Why pasture?

    Pasture development has been neglected in the high rainfall zone of the WANA region.

The zone grows many crops, tree crops and forest.

These have been given greater priority.

Pasture offers great potential for increased livestock production and does not need to compete with other land use. It can be grown between the trees. It can be grown in rotation with other crops. It can be grown on land not suited to crops or tree.
 

Annual legume pastures are the best option for the reason given below and in Better returns from the high rainfall zone 

The use of regenerating annual legumes in modern agriculture began in South Australia in the 19th century.

Of course these plants had been used in traditional farming systems in the WANA region for thousands of years before that time.

Their modern use began in the high rainfall zone at a small town called Mt. Barker in the Adelaide Hills. From there the annual legume pastures (based initially on sub clover) spread through the high rainfall zone in South Australia and other Australian states until the discovery of shorter season sub clovers in Western Australia in the 1930s and the discovery of annual medics in South Australia at about the same time. Shorter season legumes allowed farmers in the cereal zone and other low rainfall zones to take up the annual legume technology.

In the WANA region the annual legume story for the high rainfall zone has been neglected.

There was a very successful project at Sejnane in northern Tunisia but almost all the pasture development effort has gone into the cereal zone.

The replacement of the fallow within the cereal fallow rotation has received the highest priority.

In many ways this is surprising as the the use of annual legumes as a permanent pasture in the high rainfall zone is a much simpler technology.

There is no need for a change to shallow cultivation.

The management of the seed reserves is easy compared to the medic - cereal rotation.

The reasons for the neglect of pasture and the almost total lack of interest in annual legumes for this zone can be attributed to a number of reasons.

Most of the technicians have been trained in European agricultural ideas.

Their training has been local but the text books are firmly based in the agriculture of northern Europe.

In Europe pastures are in retreat as more livestock are fed grain. The remaining developed pastures are grass and nitrogen fertiliser based.

The need to protect the catchments of dams might have been a spur towards pasture development but the reaction of the policy makers has been that these catchments are over-grazed.

In fact they are under-pastured.

The number of livestock is not necessarily high.

It is the poor pasture of weeds and annual grasses that is so unproductive.

If they were sown to legumes and fertilised they could feed more livestock and provide protection for the catchment as well. The usual reaction has been to reduce livestock and plant forests.

Where to grow the pasture.  

    Suited to small farmers

    The high rainfall zone has a large proportion of small farmers.

We have already stated in the Farmers guide to cereal zone  that small farmers should place more emphasis on livestock.

Cereal farming is expensive for small farmers.

They have small areas and small fields. Small fields are difficult to cultivate and harvest economically. Small farmers cannot afford a full range of machinery. They are dependent on contractors or share farmers.

Small farmers already have flocks of sheep.

Improving the pasture will allow them to increase the output from existing flocks with few additional costs. They can also expand their flocks over time.

Expanded livestock production is extremely profitable as the overhead cost of shepherding the flock is already part of the farm budget

The flock can be expanded many time without employing addition shepherds. With the high price of sheep meat in the WANA region (both in real terms and relative to average incomes) small farmers can earn an income comparable to a factory worker from a 100 sheep.
 

Pasture under tree crops such as olives provides additional opportunities for livestock production as well as protecting the soil and fertilising the trees.

    Protection of catchments.

    The high rainfall zone is also the catchment area for many dams that have been built over the last fifty years. The rate of erosion in these catchments is generally is high.

The silt is filling the dams at an alarming rate.

Livestock and over grazing has been seen as the enemy.

Over-grazing reduces the pasture cover, leaves bare soil exposed and creates a potential erosion hazard. The reaction has been to try to reduce or prevent grazing altogether.

Sometimes forests have been planted.

In fact pasture offers enormous opportunities to protect the soil at a much less cost than forests and to provide increased output of livestock at the same time.

A good pasture will provide four or five times the output of plant material.

Existing stocking rates will not cause over-grazing.

Increased stocking rates, but not four or five times, will allow increase livestock production per head and provide plenty vegetative cover and soil organic matter for catchment protection.

    Common grazing areas.

   There are many common areas that are currently under utilised.

They have poor soils and a covered with unpalatable grasses and shrubs.

Replacing this with legume pasture produces a considerable increase in livestock production.

The application of phosphate fertiliser and trace elements will produce an abundant pasture.

The difficulty is the management. It is more efficient to manage these common areas as reasonably large pastures rather than divide them into tiny fields but finding the right balance between efficiency based on scale and individual participation by flock owners is not easy.

There are many other common areas such as road sides, waste ground and under tree grazing that should be improved.

    Types of pasture.

    There are three basic systems for the high rainfall zone.

    * Grass and nitrogen pasture.

    This is the pasture system now used in northern Europe.

It is based on high livestock prices and low nitrogen costs.

It may not survive the reorganisation of the subsidy system now taking place.

It is a fundamentally wasteful system.

When nitrogen fertiliser is applied to a grass and legume pasture it first replaces the nitrogen provided by the legumes. As more and more nitrogen is applied the grass competes more strongly with the legumes.

The legumes are suppressed but pasture production remains the same until all the legume has been eliminated.

Let us say that legumes prove 150 kg of N for a pasture.

If 100 kg of N are applied on a regular basis the grass-legume mix will change in favour of the grass. The remaining legumes will produce only 50 kg of N.

The total output of the pasture is remain much the same.

Applying another 50 kg per ha. (150 kg in total)  will continue the process of substitution of legume nitrogen with purchased nitrogen.

Research has shown that when still more nitrogen is applied production is increased to a level higher than a legume-grass mixture.

The cost however is considerable as the initial applications were unnecessary for production and could have been produce from legumes at no cost.

In the introduction we explained that the high rainfall zone provided an environment where some of the northern agricultural ideas might work.

The concept of a grass and nitrogen pasture is completely ridiculous in the Cereal Zone as nitrogen losses and erratic returns make it totally uneconomic.

In the High Rainfall Zone it cannot be dismissed completely out of hand.

Livestock prices in the WANA region are high.

Nitrogen is often subsidised and cheap.

There are still climatic and ecological problems that cannot be overcome.

While the High Rainfall Zone has more predicable rainfall and a longer growing season than the cereal zone there is still a long dry summer and spring rains can fail.

Under these circumstances the losses of nitrogen (particularly urea) can be very high.

The summer drought has another effect on the pasture besides the high losses of ammonia.

The perennial grasses that form the basis of the pasture thin out.

Suitable pasture grasses are summer dormant to resist the drought but still cannot survive at high plant densities.

The gaps between the grass plants will be filled in the autumn by regenerating annuals. The application of large amounts of nitrogen will encourage annual grasses and suppress annual legumes.

Production will be high but the quality of the annual grasses is extremely low when they dry off.

    * Grass and legume pasture.

    This is a much more realistic option.

The perennial grasses are sown with annual legumes.

The legumes provide high protein feed for livestock and fertility for the grasses.

The theoretical basis for these pastures is sound.

If annual legumes are grown as a permanent pasture rather than a rotation with cereals there is a build up of nitrogen in the soil.

The increased nitrogen will encourage annual grasses.

These can be controlled to some extent by good grazing management but over time a mixture of annual legume and grasses cannot be avoided.

The concept of the grass and legume pasture provides a better quality perennial grass as an alternative to the low quality annual grasses such as barley grass and brome grass.

    * Annual legume pasture.

    An annual legume pasture that regenerates each year may be more practical.

It is less costly to establish than one based on perennial grasses.

Their seed is expensive.

Grass seeds are small.

A good quality seed bed needs to be prepared and the seed sown at a low seeding rate (due to high cost).

The establishment of annual legumes using the pod method is cheap and easy.

There are also doubts about the ability of perennial grasses to replace annual grasses.

Over time (particularly after a longer and drier summer than normal) the perennial grass population will fall and there will be an invasion of annual grasses.

If these become a problem that cannot be controlled by grazing and hay cutting it may be better to look at long rotations with cereals (for example the Zaghouan 4 rotation) rather than perennial grasses.
 

Forestry or pasture?

     Existing and commercial forestry.

 There are considerable areas of existing natural forest in the high rainfall zone and specialist plantations of pines for commercial timber and pulp.

There are many policy makers who believe these areas should be expanded onto common pasture lands as they have been in Europe.

    We believe the circumstances are completely different and the common areas should be improved  as pasture rather than converted to forest.

    In Europe there is a surplus of livestock production and a shortage of shepherds.

Livestock production has moved from extensive grazing to intensive feed lotting.

This does not apply in the WANA region and we see no reason why these ideas should be imposed.

It is possible that the WANA economies may evolve in this direction but until they do so there is not reason to hasten the movement.

    There is a world wide surplus of pine products and the returns from pine plantations projected on current returns are poor.

Of course the same argument can be used against livestock production but the major difference is that there is a considerable premium for local producers of sheep meat.

The domestic market prefers fresh meat from local breeds rather than frozen meat from European breeds.

The same does not apply to pine products. There is no local preference. In fact local plantations find it difficult to compete against larger scale operations elsewhere.

    Agro-forestry.

    Having argued that improved pasture is a better option than plantation forestry we believe that agro-forestry could provide some opportunities.

The emphasis is still on pasture but some trees are grown.

They need to be pruned to keep them straight for timber production and to reduce shading of the pasture.

The trees can provide additional shelter and erosion protection.

The emphasis on pasture also allows trees to be grown on private or cooperatively owned common land. 

Currently plantations are mainly state owned.

The new emphasis on privatisation has led to attempts to establish more private forests but the returns from forests are slow. Large subsidies are needed to encourage private forest and except for the ideological benefit to those committed to private enterprise at any cost it is hard to see why the taxpayer should pay such benefits to land owners.

Agro-forestry can be financed through the livestock enterprise and the trees seen as a savings plan to be cashed in as a pension or other benefit after 25 years.