Understanding soil
To get the most from your fertiliser investment, it’s essential to understand the soil beneath your feet. New Zealand soils are geologically young, shaped by volcanic activity, sedimentation, and glaciation. Knowing the type of soil on your lifestyle block helps you make informed decisions about fertiliser use, crop selection, and land management.
How New Zealand Soils Formed
Soils develop through the breakdown of underlying rocks. This can happen in place through weathering, or elsewhere with soils transported by wind, water, or ice. Volcanic eruptions, in particular, have had a major impact on soil formation in many parts of New Zealand.
Common Soil Types in New Zealand
Soils are grouped by origin and appearance. Within each broad type, there are region-specific variants, often named after local areas. These include:
Volcanic Soils (Ash or Allophanic)
Yellow-brown loams (e.g. Waikato, Taranaki)
Red-brown loams and granular clays (e.g. Northland)
Poorly drained volcanic ash soils (e.g. parts of the Waikato)
Sedimentary Soils
Yellow-brown earths or brown soils (e.g. Southland)
Yellow-grey earths or pallic soils (e.g. Manawatū, South Otago)
Yellow-brown sands (e.g. Northland)
Gley podzol soils (Pakahi)
Pumice Soils
Yellow-brown pumice soils (e.g. Bay of Plenty, Central Plateau)
Gley soils formed from raw pumice
Organic or Peat Soils
Found mainly in Waikato, composed of decomposed plant matter
How to Identify Your Soil Type
To determine your soil type, check the Landcare Research portal or regional council websites. For example:
Why Soil Texture Matters
Soil texture is based on the proportions of sand, silt, and clay:
Sand: 2.0–0.06 mm
Silt: 0.06–0.002 mm
Clay: <0.002 mm
Texture affects drainage, fertility, root development, and ease of cultivation. The surface layer (where roots grow) is most important when assessing texture.
The Role of Soil Structure
Good soil structure supports:
Water retention and drainage
Root penetration and air exchange
Nutrient availability
Resistance to erosion
Crop and pasture productivity
It also affects how machinery and livestock interact with the land. For example, poorly structured soils are more prone to pugging and compaction.
Choosing the Right Farming System
Certain soil types are better suited to specific farming systems. Wet, heavy soils may need infrastructure such as stand-off pads for wintering stock. Understanding the limitations and strengths of your soil type allows you to work with it, not against it.
For more in-depth advice on choosing fertilisers for your soil type, download our practical Soil & Fertiliser ebook.
