The global soil degradation in the year 2050 is projected to be over 90%. In the UK alone, 2.2 million tonnes of eroded soil are recorded annually.
This alarming situation cannot be understated as the importance of soil health in agriculture can’t be ignored; soil health is imperative for sustainable agriculture and food production globally.
What Is Soil Health?
Soil health is the state of the soil in relation to its ability to function as a healthy ecosystem. It measures the soil’s ability to provide essential plant nutrients, retain water and support plant growth. Soil health is also a measure of the soil’s ability to resist degradation and support beneficial microbes’ growth.
Factors Determining Soil Health
Many factors determine soil health in agriculture. Some of these include the appropriate soil type for a particular crop, soil tilth, etc. However, farmers and soil scientists look for additional chemical factors to determine soil health.
Reactive Carbon
Reactive carbon is a crucial indicator of soil health in agriculture. It measures the amount of organic matter in the soil and is a good indicator of its ability to hold nutrients and water. Reactive carbon also helps to regulate soil pH and can help to reduce the risk of soil contamination.
Soil pH
Soil pH is a measure of the acidity or alkalinity of the soil. It is an essential factor in determining soil health, as it affects the availability of nutrients and the activity of soil microorganisms. A soil with a pH outside of the optimal range for plant growth (6.0-7.0) is said to be “imbalanced.”
Human Health Begins with Soil Health
Soils with a pH below 6.0 are considered acidic and may be deficient in essential nutrients such as calcium, magnesium and phosphorus. These nutrients are more readily available to plants in neutral or alkaline soils. Soils with a pH above 7.0 are considered alkaline and may contain high levels of harmful toxins such as aluminium.
Soil Electrical Conductivity
Soil electrical conductivity (EC) is an important parameter in agricultural production, as it is closely related to soil fertility and plant growth. A high EC indicates a high level of nutrients in the soil, which is essential for optimal plant growth. Conversely, a low EC indicates a poor level of fertility and poor plant growth.
Soil Nitrate
Soil nitrate is one of the critical indicators of soil health in agriculture. Nitrate is an essential nutrient for plants and is one of the leading indicators of soil fertility. Nitrate levels in soils can be affected by several factors, including crop rotation, tillage practices, fertilisers and other soil amendments.
Nitrate levels can also be affected by the presence of other soil nutrients, such as phosphorus and potassium. Soils with high phosphorus and potassium levels tend to have higher nitrate levels, which can benefit crops. However, too much phosphorus and potassium can also negatively affect soil health, so it is vital to maintain a balance.
Factors Affecting Soil Health
There are many factors affecting soil health. One of the most important factors is the type of plants grown in the soil. Different plants have different root systems and these root systems can have a significant impact on soil health. Another critical factor is the amount of water that the soil receives. Too much or too little water can both harm soil health. The types of chemicals applied to the soil can also affect its health.
Many human activities are also affecting soil health in agriculture. These include deforestation, overgrazing, farming without crop rotation and chemical fertilisers and pesticides. Deforestation, which increased globally by 12% in 2020, results in the loss of trees that help to hold the soil in place, while overgrazing can lead to the trampling of the soil and the loss of vegetation that helps to protect it. Farming without crop rotation can deplete the soil of nutrients. At the same time, the use of chemical fertilisers and pesticides can pollute the soil and make it less hospitable for plants and animals.
The Importance of Soil Health in Agriculture
Soil is a critical component of ecosystems. Soil health is vital in agriculture for several reasons:
● Healthy soils are essential for long-term agricultural productivity and sustainability. The quality of food from crops depends upon the quality of the soil. A chemically imbalanced soil can produce defective food products, resulting in a loss as the food won’t be healthy enough to reach the market for sale.
● Healthy soils are more productive and efficient in terms of water and nutrient uptake and storage. They also resist compaction and have better drainage, which leads to healthier plants.
● Healthy soils are more resilient to drought and pests and can better withstand the effects of extreme weather. Providing crops with a healthy soil bed also leads to the crops’ longevity.
● Agricultural lands are a centre of carbon production. Carbon sequestering is when soil absorbs the carbon produced from crops instead of letting it adversely affect the environment.
How to Improve Soil Health
Tillage Management
Tillage is soil preparation by stirring, digging, and other mechanical methods to make it ideal for crop production. By carefully controlling the amount and type of tillage that is carried out, farmers can help to improve soil structure, reduce soil compaction and improve drainage. This process can improve crop yields and reduce the need for inputs such as fertilisers and pesticides. In addition, tillage management can help to control weeds and conserve moisture in the soil.
Organic Matter Input
Organic matter is essential for healthy soil and adding it to agricultural land can have several benefits. For one, organic matter helps improve soil structure, improving water infiltration and retention. Additionally, increasing the soil’s ability to hold nutrients can improve crop yields and reduce the need for chemical fertilisers. Finally, organic matter can improve soil biodiversity, providing several ecosystem services such as pest and disease control.
Reduction in the Use of Pesticides
Pesticides are designed to kill living organisms, and while they may be effective at killing pests, they can also negatively impact soil health. Pesticides can kill beneficial soil organisms, contaminate soil and water resources and contribute to soil erosion. Reducing the use of pesticides can help improve soil health and reduce these negative impacts.
