Soil health is one of the government’s main concerns relating to the future of farming, so having the right advice on how to make improvements will be essential to ensure soils are protected for further farming generations.
George Hepburn, biological soils expert at QLF Agronomy, gives his seven practical steps for making a difference to your soil health.
When looking to increase soil health, the first step is to analyse the soil, because if you don’t measure it, you can’t manage it.
However, a standard UK test only provides N, P, K, Mg and pH measurements which isn’t enough to accurately determine the level of soil health.
I recommend a full spectrum test, which costs around £30 per sample. This will provide a more accurate picture of the soil make-up, by measuring calcium, boron and organic matter (OM) levels, pH, and the cation-exchange capacity (CEC) of your soil.
Always take a soil sample with a spade rather than an auger to assess compaction, count earthworms, look at rooting depths, and notice soil type changes, as you’re taking the sample.
Once you’ve assessed the condition of your soil, you can now start to make changes.
2. Remedial work
Before you can affect the biology of the soil, the structure needs to be right.
The soil micro flora and fauna need air to breathe, and food and water in the right proportions. The ideal soil structural makeup to provide this is 45% minerals, 5% OM, 25% air and 25% water.
Calcium and magnesium are extremely important minerals as they help to define soil structure. Calcium deflocculates the soil, allowing air in and water out, and magnesium does the opposite, making the soil tight and sticky. Therefore, it’s essential to get this balance right.
If there’s an inbalance you may need to apply gypsum (calcium sulphate) to help lower magnesium levels or apply calcium lime or magnesium lime.
It may be the case that simple cultivation techniques such as subsoiling, ploughing or getting a tine in to aerate the soil, could be what you need to improve soil structure.
3. Implementing a soil fertility plan
After creating the right conditions for the soil biology to thrive, you can now concentrate on providing the right inputs to make the soil more fertile.
Traditional fertilisers, although necessary, generally do not improve the fertility of the soil.
Through experience I would applying a new organically based input each year on each field to feed the soil. This could be FYM, compost, chopped straw, cover crops, lime, seaweed, gypsum, liquid carbon-based fertilisers or biologicals.
These will all encourage the soil biology either by improving its habitat or directly feeding it.
4. Use quality inputs
When implementing a soil fertility plan make sure you’re using the best fertiliser for your soil.
This could simply mean switching from muriate of potash (MOP) to sulphate of potash (SOP), however there are also many other considerations when choosing inputs.
Ensure you’re using the right type of Nitrogen for your crop, establish if there is enough sulphur or phosphate, if the phosphate reserves are available to the plant and most importantly are you getting the most out of your applied fertiliser. All of this can be established with a robust soil test.
It’s important to bear in mind that nitrogen efficiency is only around 60% and P and K can be less than that.
Using a liquid carbon-based fertiliser, such as L-CBF BOOST™, can improve these efficiencies by stimulating the soil biology and providing an energy source which aids the breakdown of the OM into a more readily available format for the plant.
Although nitrogen is essential for plant growth, don’t overlook the carbon to nitrogen ratio. Building OM is one way that a good balance can be achieved.
Increase carbon levels in the soil by making your own compost, chopping and incorporating straw, investing in cover crops, applying digestate, using humic acids, and liquid carbon-based fertilisers. These will all help to feed soil biology and build OM levels.
Wherever you can, keep the soil covered with a carbon residue to protect the soil from the elements.
6. Tissue testing
The next step is to establish if the crop is receiving the correct nutrition from the soil, as just because the nutrients are in the soil, it doesn’t mean the plant can access them.
Tissue testing can give an indication of the uptake of nutrients by the plant and help to determine if any additional remedial work and fertiliser applications have been effective.
Tests should be repeated on a field-by-field basis two to three times each growing season, as a deficiency in just one trace mineral could limit yields.
Finally, evaluation is crucial.
Go out with a spade after six months to check soil structure and compaction where you’ve made changes. Analyse the results of soil samples and tissue tests and continue to take them regularly.
Yield is important, but what we should be aiming for is long-term soil fertility so that we can continue to use the land for generations to come.
For more information on improving your soil health contact George at firstname.lastname@example.org.