It is time once again to prepare your land for planting. Before deciding how to treat your soil, have you made sure to conduct soil testing? If you haven’t, read on to find out why this step is crucial to optimising your soil treatment and maximising your returns.
Why should I test my soil?
As any farmer knows, bountiful crops are dependent on the health and fertility of your soil. Before taking steps to improve your soil health, soil testing will reveal its current state using soil testing.
Without this crucial step, your soil health is unknown and you risk employing incorrect soil treatment and plant nutrition protocols. At a time where farmers feel the impact of rising fertiliser prices, blindly treating your soil risks jeopardising your financial returns more than ever.
Soil testing reveals the health and fertility of your soil, specifically by providing two key bits of information:
- Any nutrient deficiencies in your soil
- The relative acidity (pH) level of the soil
As we will see, this information will equip you to optimise your soil treatment and protect you from wasting money overapplying fertilisers.
Nutrient Deficiencies
As our previous blogs have shown, different crops have specific requirements of macro- and micronutrients.
Soil testing will show you the current level of these nutrients in your soil and reveal any deficiencies.
This information will inform you which crops are best suited to your soil, and what inputs, if any, are required to maximise crop yields.
Demeter Ghana’s agronomists are on hand to conduct soil testing with our mobile testing unit and provide informed advice on crop selection and inputs. Click here for more information.
Relative Acidity (pH) Levels
pH is an indicator of how acidic or alkaline water is, by measuring the relative amount of free hydrogen and hydroxyl ions in the water.
Approximate soil pH can be easily determined using a litmus paper test. For precise pH levels of your soils, however, more comprehensive soil testing is required.
Contact our agronomists today to arrange comprehensive soil testing.
Why is pH a key consideration for my soils?
Having a suitable soil pH is crucial to the health and productivity of your crops. Soil pH is often considered the “master variable” of soil, as it affects the chemical, biological and physical processes of the soil.
The ideal soil pH range for plant growth is 5.5 - 8, as shown in the diagram below.
In particular, pH impacts the ability of plants to absorb nutrients. As soil becomes increasingly acidic (5.5 pH and below), the nutrients become tightly bound to the soil and are not easily absorbed by the plant roots.
This is doubly important to consider, as the use of fertilisers high in nitrogen (N) leads to soil acidification (low pH) – which if left uncorrected leads to lower yields from your harvest.
The below table shows how the efficiency of NPK fertiliser uptake changes with different pH values.
This shows that with increasing acidity in your soil, essential nutrients are less available. Therefore you need to apply more and more fertiliser for your plants to achieve the same uptake of nutrients. With increasing global fertiliser prices, this will quickly degrade any financial returns from your crops.
How do I correct soil pH?
To raise the pH (reduce acidity) of your soil, alkaline material is applied to ‘neutralise’ the soil. The common way to achieve this is through application of Calciprill®, known as liming.
Regular maintenance of soil pH is optimal for your crops as opposed to applying larger quantities of aglime on a typical 5 to 10 year basis.
Demeter Ghana been helping Ghanaian farmers neutralise their soil with Calciprill® since 2014. Calciprill® particles are made from finely ground, high purity limestone, and are twice as fine as standard aglime. Because the limestone particles are finer, they dissolve more rapidly. This provides rapid pH improvement resulting in rapid crop response.
Calciprill® is approved by Ghana Cocoa Board (COCOBOD), and has been praised by cocoa farmers for contributing to sustained increased yields.
How to apply Calciprill®?
The below table shows the recommended application rates of Calciprill® for 0.1pH improvement. Please note these values do vary depending on soil type, pH-value and crop, so make sure to consult our agronomists before commencing.
Contact Demeter Ghana today to speak to our qualified agronomists about soil testing as well as advice on soil treatment and crop selection for your specific needs.
Phone: +233 24 529 7047
Email: info@demeterafrica.com
