We know that soil is the fundamental element for agriculture, but what makes the soil healthy?
When evaluating soil health, soil scientists and agricultural extension experts at RICA often consider three main areas:
- Soil’s physical characteristics. This includes how the soil is structured, its texture, how dense or compacted it is, and how well it retains water. Healthy soil holds its shape and is able to absorb some moisture, but also porous enough so that plant roots can penetrate and extract nutrients.
- Soil’s chemical characteristics. This includes aspects such as the amount of nutrients like nitrogen, phosphorus, and potassium contained in the soil, its pH level, and its salinity. The soil’s chemical composition usually isn’t apparent to the human eye, so soil sampling and laboratory testing may be needed to determine a field’s nutrient balance and needs.
- Soil’s biological characteristics. Biological aspects of the soil include the amount of carbon in the soil, as well as the amount of microorganisms, insects, earthworms, fungi, and bacteria. When farmers practice conservation agriculture by placing organic matter on the soil – in the form of mulch, crop residues, or cover crops – that organic matter decomposes to form a humus rich in nutrients. Soil that is rich in organic matter is generally healthier, more fertile, and better able to retain moisture, which is important especially during times of drought.
Farmers who use conservation agriculture practices can see improvements across all three areas of soil health – which can ultimately lead to better land fertility, input efficiency, and increased agricultural production.