When you start to look at soil health, it can become very complicated, but taking small steps like soil testing and digging down to see what your soil looks like can make big differences. These differences are crucial, because soil is an extremely valuable asset that can play a role in yield, plant and animal health, carbon storage – the list goes on.

At a recent Agricultural Science Association (ASA) webinar, titled The Future Of Farming Is In The Soil, Fiona Brennan of Teagasc stated: “When we think of the resources that underpin our agri-food system and sector, there’s probably nothing as important or as fundamental as soil. It underpins literally everything. It is the foundation on which the sector is built.”

Fiona went on to explain the multi-functionality of the soil ecosystem that enables life on earth.

In fact, over one-third of all life on the planet is stored in the soil and there is more carbon stored in soil than there is in the atmosphere and forests combined.

A recent study by Teagasc also showed that there is a lot more potential in our soils to store carbon.

Managing soils properly into the future will be essential from a carbon storage perspective. Fiona described some of the stats on soil and how we can enhance soil health.

Some soil facts

  • Soil is essentially a non-renewable resource.
  • It can take hundreds of years to form a single centimetre of soil.
  • Soil is currently being degraded faster than it can be replaced.
  • In the US for example, it’s being degraded about 10 times faster than it’s being replenished.
  • Each year, we lose 24bn tonnes of fertile topsoil.
  • The majority of the world’s soils are in fair, poor or very poor condition.
  • 33% of soils are moderately to highly degraded.
  • The UN estimates that there are 60 years worth of viable topsoil left.
  • 60-70% of EU soils are considered unhealthy.

    • Threats to soil

  • Sealing – when we build on top of soil it loses function.
  • Compaction – one of the main threats to soil in Ireland.
  • Over fertilisation.
  • Loss of organic matter.
  • Loss of above-ground diversity.
  • Pollution.
  • Soil erosion.
  • Climate change.

    • How do we enhance soil health?

  • Check your soil health like you would check your machinery.
  • Avoid physical damage by keeping vegetation on your soils.
  • Maintain organic matter.
  • Diversify your crops – monoculture above ground results in monocultures below ground.
  • Only use the fertilisers you need.

    • Robbie Byrne, a Nuffield Scholar investigating biological farming practices, stated: “Modern agriculture, for the last probably 60 years, has been treating symptoms and not the cause.”

    Noting that the wheel keeps turning and change keeps occurring, he commented that there is no magic bullet to fix problems in our soil, but there is plenty of information available to people and farmer-led research is changing the tide across the world and while there will be mistakes and failures along the way, there will also be successes.

    Earthworms can improve drainage, aeration, organic matter content and make nutrients more available

    Robbie encouraged farmers to go out and have a ‘pooch’ – get your spade and dig a hole to see what’s happening in your soil. There can be massive changes in soil across fields and farms. Noting differences in structure, colour and earthworm numbers are all places to start.

    Earthworms can improve drainage, aeration, organic matter content and make nutrients more available. In order for earthworm numbers to increase, they need food from things like cover crops and multispecies swards, which provide diversity.

    The liquid carbon pathway

    Robbie outlined the liquid carbon pathway as something we will all be very aware of in the future, stating that soils without living plants and roots are not the future.

    The basics of the pathway are that growing plants perform photosynthesis, the plant roots provide root exudates to the soil, which in turn increase microbe numbers, macro fauna and help the soil food web to function.

    Robbie encouraged people to look at alternative fertiliser sources like carbon fertilisers, which can reduce nitrogen usage and feed the soil

    A functioning soil will then have increased levels of soil organic matter. An 1% increase in soil organic matter content can provide €15/ha of extra free nitrogen and can also result in significantly more water being held in every hectare of soil.

    Robbie encouraged people to look at alternative fertiliser sources like carbon fertilisers, which can reduce nitrogen usage and feed the soil, providing other elements such as calcium, sulphur, magnesium, zinc, copper, boron and manganese.

    The farmer’s view

    Once we have examined our soils and know what needs to be improved, then we can make informed management decisions. Gareth Culligan is a tillage farmer from Co Louth.

    He described some of the techniques he is using on his farm to improve soil health, such as reduced tillage, cover crops, rotation, companion cropping and mixing varieties.

    Soil testing and leaf analysis also play an important role in finding solutions to problems on-farm. Soil testing is carried out every three to four years. Albrecht samples are also carried out. This test shows the ratio between calcium, magnesium, potash and sodium, all of which can affect soil pH.

    “When these elements are balanced, soil health and structure improves. These tests show the total amount of nutrients in the soil that are locked up, so by improving soil health and biology, these nutrients can be more available to plants.”

    Gareth will carry out an average of five leaf analysis tests in his wheat this season, to examine deficiencies and excess nutrients in order to provide nutrients that the plant needs and reduce fungicide use.