Zambia Agribusiness Society

It is easy to understate the importance of soil. It seems benign. It seems inert. But the ground beneath our feet is literally teaming with life – most of it too small for us to see or register as important. But all of it is important and vital to our human life systems. Soil provides the anchor to plant roots. It holds water and nutrients. It is home to micro-organisms and so much more. When we think of soil, we often think of the physical properties of the soil. How big are the particle sizes? Sand is the biggest, silt is a medium size, and clay is the smallest. We think about the water holding capacity. Clay soils have a lot more surface area of the individual particles and so therefore can hold a lot more water than sandy soils. We think of availability of nutrients and soil structure as indicators of healthy soil. But it is these last two that offer a huge level of complexity that we rarely think about. Nutrient availability Whenever a soil is lacking in available nutrient f