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Corangamite Region   'Brown Book'   - How to optimise your soils to enhance productivity
Case Study
Evaluating the NZ Visual Soil Assessment and Northern Rivers soil health assessment kits in the Heytesbury region compared with conventional laboratory measurements
Source: Greenwood et al (2008)

Project objective:
Adaptation, modification and field testing of farmer self assessment tools to monitor and manage soil quality for use by farmers, groups and advisers.

Method:
Data analyses compared the visual soil assessment scores by two assessors using the Northern Rivers Soil Health Card and the New Zealand Visual Soil Assessment, and the quantitative soil chemical and physical data.

Outcome:
From a researchers perspective, the two soil health assessment tools compared in this project - the Northern Rivers Soil Health Card and the New Zealand Visual Soil Assessment - have not met the expectations of the project team with regard to consistency between assessors, nor detection of soil health issues. Some of the factors assessed, such as soil strength and earthworm numbers, are sensitive to soil water content and therefore the scores vary with seasonal conditions. Statistical comparison of visual soil assessment data with quantitative soil chemical and physical data showed some interesting trends, but no strong correlations. While these farmer self assessment tools may be beneficially demonstrated in group situations, we recommend that greater priority be given to conducting and interpreting soil nutrient tests to plan fertiliser applications. In particular, whole farm nutrient maps, as promoted by the Heytesbury Soil and Water Dairy Action Program, can be very useful.

Value:
Both soil health assessment kits are useful educational and practical tools that landholders can use to monitor the health of the soil.

General comments:
The NZ VSA and Northern Rivers Soil Health cards were well received by landholders, but it was suggested that scoring of soil health has the potential to be controversial and contentious for individual farmers and the industry when scores are low (or poor) compared with benchmarks.
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This project is supported by the Corangamite Catchment Management Authority, through funding from the Australian Government’s Caring for our Country

Page Updated: September 2013
Produced by AS Miner Geotechnical