Costs and returns

for

Shallow cultivation

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Understanding the packages

    Readers will have grasped by this stage that deep ploughing and shallow cultivation are completely different systems. They are not a simple adjustment of the working depth. (see Buyers' guide to scarifiers  for the technical details)
 

    * The deep ploughing package.

    1st cultivation with deep plough.

    2nd cultivation with cultivator or tandem discs.

    3nd cultivation with cultivator or tandem disc.

    4th Perhaps a passage of the harrows.

    These are the minimum operations needed produce a seed bed. There are no opportunities for reduced till or direct drill without a seriously flawed seed bed.

    5th Seeder and fertiliser - together or separate.

Implements:

                    = 1. deep plough

                       + 1 cultivator or tandem disc.

                        + harrow

                       + 1 seeder.

    * The shallow cultivation package (assuming a conventional till).

    1st cultivation with scarifier.

    2nd cultivation with scarifier

    Harrows used behind scarifier.

    3nd Tined seeder for seed and fertiliser.
 

Implements:

                = 1 scarifier (change points for 1st and 2nd cultivation)

                + 1 harrow.

                + 1 seeder

    * The alternative shallow cultivation package (assuming conventional till)

    1st cultivation with  scarifier - seeder.

    2nd cultivation with scarifier -seeder.

    3nd Seeding with scarifier -seeder for seed and fertiliser.
 

Implements:

                = 1 scarifier-seeder.

                    + harrow. 

Capital cost of the packages

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    Table 1

    This show the capital cost of some common implements.

The cost has been divided by their working width to provide a comparison per metre.

The actual capital cost has then been calculated using one metre of a linkage scarifier as the basic unit = 100 per metre.

Type of implement.	Cost per metre of working width compared to linkage scarifier (cheapest option)
Scarifier, linkage model with depth wheel	100
Scarifier, trailed model	214
Disc plough, linkage (specially designed for shallow cultivation - not the standard three disc model)	180
Disc plough trailed - again shallowccultivation model.	514
Cover cropper or tandem disc, linkage	116
Cover cropper or tandem disc, trailed	327

                             

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If we put these implements together into packages for a small farmer we find:-

    * For deep ploughing.

    The usual seeder is a cheap model that does not cultivate the soil and does not sow fertiliser.

    * For shallow cultivation.

If we add the tined seeder (which is more expensive than the seeder above) to the package we find the the shallow cultivation package is still competitive in capital cost.

The scarifier -seeder is more expensive than a standard tined seeder but it is still competitive if it is used as a replacement to the scarifier + tined seeder package or to the whole deep ploughing package.
 

Working cost
 

    Where the shallow cultivation package has been used in the WANA region it has proved to be effective and low cost.

In Jordan the Jordan Cooperative Organisation - a major cultivation and sowing contractor used scarifiers and seeders because they were effective and low cost.

Similarly in Libya and Iraq but there is no experimental data on any of these projects that I can find. It was so obvious that it did not need to be proved.

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Table 2

Relationship between tillage depth and costs. (ACSAD no date)

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    * The first cultivation.

    The above table from ACSAD shows the lower cost of shallow cultivation.

The experiment is fundamentally flawed as it used the same three-disc linkage deep plough for all three treatments.

The scope for turning the power saved into increased rate of tillage is limited. The tractor cannot work too fast.

Friction with the soil increases sharply as tractor speed increases. Double the speed does not require double the power but considerably more.

The soil is thrown into large ridges if the tractor is working too fast. These ridges require work with cultivators and harrows to level them.

A careful examination of the above experiment shows that the improvement in rate of tillage from 20 to 14 cm was greater than from 14 to 8 cm.

This seems to indicate that the limits of increased speed were already being approached at the 14 cm depth.

Even with the same three-disc plough the shallow cultivation treatment is substantially cheaper.

If the ACSAD experiment had compared deep ploughing as a package with shallow cultivation as a package the cost would have been half for the initial working of the soil.

    * The subsequent cultivations.

    With shallow cultivation there is flexibility.

The seeder can be used directly after the first cultivation (reduced tillage system) or the land can be cultivated again with the scarifier for the conventional tillage system.

The cost of the secondary cultivation will be similar under both deep ploughing and shallow cultivation.

    The great difference is that farmers using deep ploughing do not have the choice.

The ground is so rough after deep ploughing it must be worked at least once even if herbicides are used for weed control.

In fact our experience in the region is that the land is worked two and sometime more times just for seed bed preparation.  While the cost of each cultivation may be the same as the shallow cultivation system there are more of secondary cultivations.

    Farmers' experience in the region reinforces our adage that the best way of breaking down clods is not to produce them in the first place.

Using a scarifier at a shallow depth when soil moisture conditions are optimum and pulling a harrow behind will certain reduce initial clod production to a minimum.
 

Time - costs and returns
 

    If there have been few attempts to cost deep ploughing against shallow cultivation there have been no attempts to cost the time saved.

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Chart 1

     Shows the relationship between time of seeding and weed control.

The experiment was conducted on the South Australian Government Demonstration Farm at El Marj in eastern Libya.

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    The experiment can serve as an indicator for the reduced returns from deep ploughing.

If one assumes that deep ploughing takes at least twice as long as shallow cultivation it is possible to make some calculations depending on the machinery resources available to the farmer.

If there are surplus resources the deep ploughing program can be carried out on time.

If the tractors are fully utilised then we can see the farmer is caught in a trap.

Fewer cultivations will take less time. Weed control will be poor and yield will be reduced.

The same number of cultivations will take longer. Weed control will be good but late sowing will reduce yields.

    The third alternative is to purchase more tractors and carry out the program in the same time. The farmer is faced with greater costs or reduced returns due to deep ploughing.
 

Placement of fertiliser.
 

    Applying the fertiliser with the seed saves time and money but the amount is insignificant.

The real benefit comes from placement of the fertiliser near the seed.

By increasing the response from small amounts of fertiliser the risk of loss is reduced and many farmers will use fertiliser who did not use it before.

Placement proved to be tipping point in South Australia for fertiliser use. Before placement only a few farmers used phosphate.

After fertiliser placement seeders were available 85% used it within ten years.
 

Seed savings.
 

    The combined package of shallow cultivation, level seed bed and tined seeder will allow seeding rates for cereals to be reduced significantly.

Let us assume a 50 kg/ ha reduction in seeding rate.

Let us assume that a 2.50 metre tined seeder is used by a contractor to seed a modest 100 ha every year. In fact the machine is capable of seeding a much larger area than this. My experience with seeders of this size was that 15 ha a day could be sown during daylight hours.

Each year 5000 kg of seed is saved.

Let us assume a price of $400 per tonne for clean, fungicide treated seed.

Saving = $2,000. per year.

The seeder will be easily paid for in five years on seed savings alone.
 

Level seed bed.
 

     * Herbicide application.

    The level seed bed makes herbicide application easier.

It is a similar story to the fertiliser placement.

The cost savings are not the point.

The level seed bed and better spray equipment can provide the tipping point for herbicide use.

At present the difficulties are too great for most small farmers and many larger ones.

     * Harvesting.

    The opportunities for improving harvesting efficiency are enormous in the WANA region. These will be described later. ( Harvesting ) The starting point is a level seed bed.