Feeding the world’s growing population

New Zealand’s reputation as a quality food producer is growing.

Optimising food production

Over the next 50 years farmers around the world will need to produce more food than has been grown over the past 10,000 years.

Best use from a limited resource

Fertiliser helps farmers produce food efficiently by replenishing the soil. But fertiliser needs to be used responsibly.

Responsible and sustainable nutrient management

The Fertiliser Association invests in research and tools to ensure farm profitability while minimising nutrient losses to the environment.

The Fertiliser Association of New Zealand promotes and encourages responsible and scientifically-based nutrient management.

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What is a soil phosphorus 'Olsen P' test?

Scientists use soil tests to assess what level of phosphorus in the soil is available to plants. In New Zealand, the soil test used is the 'Olsen P' test, which provides an estimate of what is considered to represent the pool of phosphorus accessible for plant uptake as 'available phosphorus'.

By measuring the Olsen P levels, it is possible to estimate how much phosphorus is sitting in soil solution and a proportion of that sorbed to soil colloid surfaces. This, along with other farm specific information, is used to estimate how much phosphorus is needed to 'maintain' the soil phosphorus status.

High producing farms

In high producing farms, more phosphorus is being removed and more 'available' phosphorus is needed to keep soils at 'maintenance' fertility levels. For this reason, the recommended Olsen P level for a high producing farm is higher than the recommended range for average production.

Pastoral soils

In pastoral soils, maintaining adequate levels of phosphorus is required to support clover growth, which has a higher phosphorus requirement than grass. Supporting clover growth provides a valuable source of nitrogen, reducing the need for application of nitrogen fertiliser.

The Fertiliser Association of New Zealand and Dairy NZ funded development of the Nutrient Management Adviser Certification Programme (NMACP). This industry-wide certification aims to ensure that advisers have the learning, experience and capability to give sound nutrient advice.

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15 April 2021

Good soil fertility is critical for our agricultural economy. We welcome today's report. One of the areas highlighted in the report is soil quality, and in particular, soil fertility as measured by the 'Olsen P' soil test. However, the report's analysis is based on a limited data set. Our analysis of industry data suggests a slightly different picture than presented in the report.

31 March 2021

Congratulation to Tim Jefferd, Regional Manager for the Eastern North Island at Agricom, who became the 300th person certified through our Nutrient Management Adviser Certification Programme.

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