Soil analysis for the season ahead

September 2019

Gavin Mathews, Bachelors in environmental management. Send an email to gavmat@gmail.com

There are many areas to focus on when getting your fields prepared for the coming season. This task should start well in advance to give you time to plan effectively. When the combine harvesters pull into the wash bay and the last of your crop is delivered or stored away; then it is time to start thinking about the season ahead.

To remain competitive in an ever-changing environment the farmer needs to always be one step ahead. In this article I will focus on one of these areas: Soil sampling. Doing analysis of your soil is like reading a map and understanding which direction to head into. Results need to be received well in advance so that you have time to understand them and to follow their guidelines as precisely as possible. 

It is hard to believe that there are still many farmers operating today that do not make use of this valuable tool. In my opinion; soil analysis should be the foundation upon which you build your farming business. Everything we do as farmers is in direct relation to the soil. The soil is from where our food and our livelihood come, which is why we need to take care of it as best we can. The soil is living, full of minerals, nutrients and bacteria which provide the crops that we plant the food they require to grow. If we keep taking and never replacing, then we will soon find that what we are doing is not sustainable. 

All living things have various attributes and qualities. They also have different needs and requirements. Some living things will die out and perish if they are not sustained in the correct manner. The same goes for our soil! Achieving and maintaining appropriate levels of fertility, especially plant nutrient availability is extremely important if agricultural land is to remain capable of producing the food we need as a human population into the future. Soil analysis is a tool that we need to make use of to be able to ensure this. 

HOW DO WE DO IT?
A soil analysis seeks to identify which nutrients are available to plants in the soil as well as which nutrients are lacking. Examples of these nutrients are elements such as phosphorus, potassium and magnesium. There are many of these nutrients and all of them play a vital role in sustaining our plants. 

To do a soil analysis one needs to physically extract a sample of soil with the aid of a soil auger and analyse it in a laboratory. One cannot however take one sample from each field and take it as an accurate reflection. The soil is made up differently across a large area which is why we need to do grid sampling in order to better interpret the different zones of the land we are going to plant. For optimum yields one should do thorough sampling. Each grid that is sampled should be boxed and labelled accurately for easy interpretation on the results sheet. Once your samples are securely packaged and labelled you can send them to your closest laboratory for testing and analysis. Many fertilizer companies do provide this service at an extra cost.

HOW DO WE INTERPRET IT?
When you receive your printout of your soil results it can often be quite intimidating as it will look like another language of big words, numbers and figures that are impossible to read. Fortunately, there are people who are trained and educated in this field and will be able to give you a breakdown of the results and explain to you exactly what your soil needs and how much it needs. Most fertiliser representatives will also be able to give you guidelines based on the soil sample recommendations you receive. 

WHAT ACTION DO WE TAKE? 
In order to achieve the best yields possible, you should always strive to provide your plants with everything they need to grow. Of course, one always needs to keep budget in mind. Remember that you can rather build towards improving your soils over a period of time rather than trying to do it all in one year and going bankrupt in the process. As long as you are continually improving and achieving better results then you are heading in the right direction. 

Once you have interpreted the soil sample results you need to decide which fertilizer products you wish to use in order to correct your soils as best possible. You then need to place your order with the fertiliser company well in advance to allow you time to apply it accurately with a spreader according to your grid requirements. Accurate calibration is essential to apply the correct amounts of fertiliser.

Maintaining and building the fertility of our agricultural soils is of paramount importance, not only for us today, but especially for the future generations that are to come. Soil analysis and its interpretation is an important management tool which can help us achieve sustainability.

Publication: September 2019

Section: Pula/Imvula