Soil functioning

The issue and impact

Soil is the fertile skin of the Earth. It stores water, nutrients and agrichemicals, provides a habitat for a huge range of organisms, and is our primary water filter. Monitoring shows that land use intensification (with increased livestock numbers, fertiliser and irrigation) threatens these soil functions. Leakage of nutrients and pathogens into aquifers and waterways are strong signals that our ecosystems are becoming degraded.

• Fertiliser use in New Zealand has increased more than 10 fold in the past 15 years.
• Pastoral agriculture on permeable pumice soils is contributing to the degradation of Lake Taupo.
• The expansion of dairying in Canterbury and horticulture and viticulture in the Hawke's Bay on to permeable soils poses a threat to groundwater quality.

Degradation of our soils through intensification and pollutants in our soil and water threaten New Zealand's 100% pure and clean, green international positioning - annually worth up to $1 billion to the tourist industry and $600 million to the dairy sector.

Research needs

• Identify the limits of intensification for sustainable land use in terms of soil compaction, nutrient application, agrichemical leakage and biological function
• Produce tools for developing and managing sustainable, intensified land uses
• Match land uses to the capabilities of soils and the local environment.