Soil testing: Why is it so critical?

WHY IT MATTERS: Similar soil types, conditions and species present. Very different levels of inputs and therefore production.

This is the second of a series of articles being prepared by Gambier Seeds for The Border Watch. These will feature in the On The Land section during 2021. The focus of these articles will be to optimise productivity from on farm pasture and forage bases. At Gambier Seeds we believe pastures and pasture renovation are an investment, not only in your farm production and profitability, but in its future.

FERTILISER is one of the top three costs for most grazing enterprises.

Optimal pasture growth can only be delivered where soil conditions and nutrient levels are optimised.

Compared with pasture species selection, breeding programs or animal health programs, there is very little work put into farm fertiliser programs on grazing properties.

The opportunity to change this exists, and has existed for many years, yet it is not undertaken.

The answer is to undertake a regular and comprehensive soil testing program, which is in turn used to create a fertiliser program, which is then carried out.

This is the answer to optimising your fertiliser dollar spend, but also to achieving production goals for your farm.

Sounds simple? It is.

Sound expensive? It actually is not really, and certainly isn’t in the medium to long term, or where production isn’t meeting enterprise goals on your farm.

There are few who do not soil test.

However, testing is usually only undertaken on paddocks to be cropped or renovated, or randomly over sections of the farm.

This information delivers value, but it is only relevant to the paddock or section that was tested.

It is dangerous to assume this information as a basis for decision making to be applied on a larger scale across other areas of the farm.

I recommend a program of soil testing every paddock (grazing/cropping paddocks – not holding paddocks or yards) every three years.

For this program we use a “basic” soil test to check for the major nutrients and assess pH and Ec.

Where we intend to renovate or crop, we undertake a comprehensive test in the year of beginning the program.

By undertaking full farm testing at the one time, a complete and accurate picture of the farm soil nutrient status is compiled.

From this we can determine a fertiliser program or soil conditioner application program.

This methodology not only identify issues or problem areas, it also highlights the nutrient status of paddocks that are performing well and identify “base levels” that are currently working well for us on our farm under our management style.

These show us base levels we should be targeting.

This aspect is forgotten in most testing regimes where tests are usually only undertaken on paddocks with visual issues.

Other advantages of adopting this full farm testing approach on a regular basis are:

* Ability to compare paddocks of similar soil types with one another.

* Ability to identify and correct declining nutrient levels before problems are encountered.

* There are multiple results to show trends across your farm and soil types, but also over time as you repeat the tests.

* Ability to avoid any “outlier results” which can occur from single tests of paddocks where there are no comparisons to confirm results which may be unexpected.

Compared with single or random testing, the full farm “basic” testing price tag will be higher – but it is only once every three years (as a guide – may vary on advice).

Also, you need to balance the testing cost as a percentage of your fertiliser spend over the same period.

We undertake these testing programs of our clients where they do not have full programs with their fertiliser suppliers.

We know the value of understanding the soil nutrient status regarding total farm production.

Seriously consider going down this path if you are not already doing so.

Of the clients that have adopted this practice, none have been disappointed with the outcome or failed to make significant changed to their fertiliser programs as a result.