- 8.1 Soil
- Programme Title:Development of self-assessment scales for land owner resource management goals
- Programme Title:Development of an operational framework to determine nutrient budgets (NPKS) at the farm, regional and national level for pastoral agriculture.
- Programme Title:Development of an operational framework for measuring, monitoring and reporting pastoral soil sustainability at the farm, regional and national level.
- Programme Title: Soil quality indicators for sustainable agriculture
8. SUSTAINABLE AGRICULTURE
In the Government’s 2010 Strategy several areas were identified as posing environmental and long-term productive capacity risks for land use. These include:
- land degradation as the result of soil erosion, soil compaction and other factors;
- rundown in soil health; and
- effects on water quality and availability.
Environment 2010 has identified a number of actions required for managing land resources. These include:
- encourage land management practices that reduce soil loss, and maintain or enhance the quality of waterways, groundwater and coastal waters and protect them from suspended sediments, nutrients, harmful microorganisms and other contaminants;
- avoid, mitigate and remedy the impacts of land-related hazards, including flooding, subsidence and erosion; and
- develop land management skills and land use systems that will enable people and communities to provide for their social and economic wellbeing.
MAF Policy, through it’s Sustainable Agriculture Facilitation Programme, pursued the action areas as identified by the Environment 2010 Strategy. This required targeting operational research around the identified priorities and using the results in the policy development process. MAF also aims to use the information provided, where relevant, in extension programmes for interested parties such as farmers and regional councils.
Priorities in this area are established by a MAF Policy-wide team but Alan Walker and the Rural Resources Unit play a particularly prominent role.
The 1995/96 research programme included projects directed at:
- providing indicators, measures and models for assessing resource sustainability factors such as soil quality (8.1);
- developing and improving measures of greenhouse gas emissions from agriculture (in particular methane and nitrous oxide) (8.2);
- improving water quality through developing models for measuring nonpoint discharge from agriculture, and developing guidelines for construction of wetland treatment systems for dairy shed discharges (8.3);
- examining constraints on and strategies for farmer adoption of sustainable technologies and management practices (8.4);
- developing cooperative, community based approaches for improving communications between farmers and scientists, and joint development of strategies, for sustainable land use within the semi-arid land research programme (8.5); and
- • developing methods for, and initiating, ships’ ballast water sampling to identify and assess the risk from invasive marine life (8.6).
8.1 Soil
Soil is a fundamental and finite resource which is necessary for life on earth. The continued maintenance of its health and quality is of paramount concern to human survival. As such, the determination of indicators of soil quality has become an important issue, especially in terms of the use of such indicators for monitoring and maintaining sustainable agricultural systems. Involvement of farmers in developing these indicators is likely to increase their adoption of more sustainable practices.
8.1.1
Programme Title: Development of self-assessment scales for land owner resource management goalsResearch Leader: Mr T Parminter Institution:AgResearch |
Summary
This project involved farmers in developing resource indicator scales to encourage greater awareness of trends in resource condition. Scales were developed for water quality, productive pastures and productive soils at farmer workshops, using technical information supplied by the farmers and by scientists. The scales are considered to be unique in being developed from material provided by landowners themselves. The results demonstrate that many rural landowners are committed to improving their stewardship of natural resources and can achieve a lot themselves by pooling their combined knowledge and experience with available scientifically based technical information.
Description
To develop quantitative resource indicator scales for sheep and beef farmers by running workshops by farmers;
- establishing their own resource management goals;
- evaluating their progress in improving the sustainability of pastoral production systems;
- making case studies of actual examples of high, medium and low points on the scales from examples identified by farmers and regional council staff; and
- making scientific assessments of each case study example using a similar process to that for the High Country vegetation index scale, and develop a range of objective criteria from the assessments to parallel the farmers’ scales.
Approach & Outcomes
Rural land owners are often aware of extremes in resource condition but seldom consider it systematically. Researchers considered that development of resource indicator scales would encourage land owners to be more aware of the condition of natural resources around them. Enabling landowners to record their subjective assessments and review their results over a long term would assist them to identify trends in resource condition before they have reached extreme states. The scales go beyond other attempts at establishing resource assessment tools, by providing landowners with guidelines for looking at management options, which involve lists of management practices and further testing.
To develop the scales, landowners in the Waikato, Manawatu, and Canterbury were formed into three focus groups, at times supplemented by LIC dairy farmer discussion groups. Land owners were presented with a range of resource indicators in the form of a questionnaire. The intention had been to use the standard Thurstone psychological measurement procedure, to develop twenty point scales, for each sustainability componentidentified by farmers. However, this procedure was not found to be appropriate and instead an index using the same indicators was developed.
The project benefitted from its association with Federated Farmers’ development of Management Practice Guidelines. The Guidelines provide excellent reference material for landowners wishing to implement some of the management practices listed in the supporting material to the resource assessment questionnaire. The qualitative material in this project was also linked with the quantitative resource indicator set being developed by the AgResearch soils group.
- Resource indicator scales were developed for water quality, productive pastures and productive soils.
- Background information was provided to assist users interpret the results of applying each of the scales.
- A working booklet was prepared for field testing each of the prototype scales.
In developing the scales, the farmer groups:
- described the indicators used by individual farmers to assess resource condition;
- developed the method of assessing each indicator so they are practical and appropriate;
- supplied the terms and language to be used in publications;
- reviewed scientists’ suggestions for improving the indicators;
- reviewed technical material provided to interpret the indicators; and
- field tested the scales to ensure their practicality.
In addition, a technical group of scientists and regional council staff was formed for each resource scale. These groups provided:
- clarity about biophysical interactions that focus group members were observing;
- suggestions on apparent inadequacies in the material provided by the focus groups;
- a check on the technical accuracy published from the groups’ reports; and
- suggestions on presentation of resource scale reports and prototype preparation.
Researchers concluded that the scales are unique in being developed from material provided by landowners themselves. For the landowners involved, a useful assessment scale had to integrate all the indicators they used to assess resource condition. They also wanted an assessment that could be compared with the results of commonly available laboratory tests. So that resource assessment would be regularly carried out, it had to fit into existing farming routine, build upon land owners’ skills in observation and require the minimum of specialist equipment.
Further development of these indexes is being carried out in 1996/97.
8.1.2
Summary
This project aimed to develop an operational system combining models of nutrients, fertiliser use and soil test databases to make nutrient budgets. Nutrient budgets are environmental indicators, constructed by calculating the difference between net inputs and losses of nutrients from a unit of land.
A software package for computing nutrient budgets for nitrogen, phosphorus, potassium and sulphur was developed based on previously produced biological nutrient models. The need to develop databases to generate information on nutrient fluxes (rates of flow) at the catchment, regional and national level was identified. Information was required on fertiliser inputs, stock movements, animal feeds and animal production. Information on the nutrient content of farm animals and their products was reviewed and summarised.
Description
To develop an operational system to interface dynamic nutrient models, fertiliser use and soil test databases which will enable farmers, resource planners and policy analysts to calculate nutrient balances at the farm, regional and national level by:
- developing in conjunction with other soil testing laboratories, appropriate systems and databases to record national and regional nutrient inputs and soil test data;
- developing systems to apply dynamic nutrient models at a national and regional level to calculate nutrient outputs;
- adjusting those models such that both input and output data can be reported and recorded at farm levels; and
- combining all of the above into a single networked system for local, regional and national use.
Approach & Outcomes
Nutrient budgets are environmental and nutrient management indicators. They are constructed by calculating the difference between net inputs and losses of nutrients from any given unit of land. The OECD has established a joint working party to develop an Agricultural Nutrient Balance Indicator. The major use of nutrient budgets in New Zealand is likely to be to determine net changes in nutrient fluxes (rates of flow), particularly for diagnosing situations of nutrient mining or excessive nutrient use.
This research was based on dynamic nutrient models already produced by AgResearch for phosphorus (P) and sulphur (S) for use in assessing the economic outcomes of fertiliser policies and strategies. Other models are being developed for nitrogen (N) and potassium (K). A software package for computing nutrient budgets for N, P, K and S was developed based on previously developed biological nutrient models. It was found that a single application could be developed to be used either at farm level or at regional or catchment level.
This programme is essentially a short-term analysis, with its measured product quantities and limited timestep. But at the same time, the objective of the users is expected to be analysis of sustainability, which implies a long-term view. This raises a problem when calculating, for example, nitrogen losses. In the long-term, N losses will tend towards equilibrium with N gains. The Nutrient Budget uses this assumption to increase N losses in response to N gains, with the result that the N balance is always close to zero. In reality this is sometimes not the case, in that a system subjected to a sudden increase in N inputs may take several years to reach equilibrium again.
The programme in its current form is essentially a "first cut", and as such there is some variation in the quality of the equations used to predict non-measured nutrient flows. Another limitation may be the quality of input information supplied. The programme framework could easily be adapted to incorporate other nutrients, including trace elements, assuming, of course, that the required underlying equations and composition data are available.
Reports were written on Nutrient Budget Software and on the Mineral Content of Pastoral Farm Animals and their Products. Information on the nutrient content of farm animals and their products was reviewed and summarised in the following table:
Table 1: The approximate mineral content of Livestock and Farm Products that leave the farm gate.
| Farm Enterprise |
N | P | Mg | Ca (g/kg) |
Na | K | S |
| Farm Products Milk |
5.7 | 0.95 | 0.12 | 1.2 | 0.40 | 1.4 | 0.3 |
| Wool | 165.0 | 0.14 | 0.25 | 1.8 | 0.05 | 1.0 | 34.0 |
| Antler | 148.0 | 102.0 | 2.0 | 180.0 | 3.5 | 0.9 | 37.7 |
| Livestock Cattle |
32.6 | 8.0 | 0.4 | 16.4 | 0.9 | 2.2 | 3.9 |
| Sheep | 34.0 | 7.0 | 0.4 | 14.4 | 1.0 | 2.3 | 4.0 |
| Deer | 37.1 | 9.0 | 0.4 | 18.5 | 1.0 | 2.2 | 4.1 |
| Meat Beef |
33.6 | 2.1 | 0.2 | 0.03 | 0.5 | 3.9 | 1.5 |
| Lamb | 26.1 | 1.6 | 0.2 | 0.17 | 0.7 | 3.1 | 1.5 |
| Venison | 35.7 | 2.0 | 0.3 | 0.04 | 0.5 | 3.6 | 1.5 |
8.1.3
Summary
This project aimed to identify suitable indicators on soil sustainability for pastoral soils. A list of quantitative and qualitative tests for defining soil chemical, biological and physical quality was drawn up. Limitations in current knowledge were also identified.
Description
To develop an operational framework for measuring, monitoring and reporting on soil sustainability indicators for pastoral soils, at the farm, regional and national level by:
- deciding on a set of chemical, biological and physical soil indicators for pastoral soils;
- developing on-farm monitoring and sampling protocols (sampling frequency, intensity, sample numbers etc.);
- modifying, if necessary, the above tests so they are suitable to routine laboratory use; and
- identifying and scoping the necessary databases and reporting systems.
Approach & Outcomes
This project enabled scoping and identifying the work needed for an ongoing project funded by the Foundation for Research, Science and Technology (FRST). Part of the work was undertaken under the MAF project, with the rest of the work being still underway in the FRST project.
Proposed soil quality indicators were selected based on Ministry for the Environment (MfE) criteria and some additional criteria and were classified into 3 main categories; Chemical, Biological and Physical. Where necessary each category was subdivided further according to the purpose of the indicator. Each individual indicator was listed along with a brief outline of the current method of measurement and/or a description of the indicators’ current status. Limitations in current knowledge were identified.
Where possible both quantitative and qualitative indicators were given. The focus was on quantitative indicators, but "self assessment" indicator scales would also be useful.
The indicators include a considerable number of tests, but it was considered that only a small subset of these tests would be used routinely on a widespread basis by land-users to monitor soil quality. These are:
Chemical:pH, Olsen P, Quick Tests Ca, Mg, K, Na, SO4-S, available organic S, exchangeable Al.
Physical:a measure of soil aeration (e.g. macroporosity) and a measure of soil resilience (e.g. aggregate stability).
Biological:a measure of the available quantity of biological substrate and a measure of the biological activity for this substrate.
A report on indicators for soil quality in pastoral agriculture was produced.
8.1.4
Programme Title: Soil quality indicators for sustainable agricultureResearch Leader: Dr K Cameron Institution:Lincoln Soil Quality Research Centre |
Summary
Soil quality indicators are required for monitoring and maintaining sustainable agricultural systems. An international workshop of scientists was organised. The workshop identified criteria for soil quality indicators and then identified potentially useful physical, chemical and biological indicators. It was emphasised that as the knowledge base is expanding rapidly the list was not exhaustive or final.
Description
To identify and define indicators of soil quality which can be used to provide sound policy advice on the sustainability of New Zealand agriculture by:
- conducting a critical review of the international literature to identify potential soil quality indicators which could be used under New Zealand conditions;
- holding a one day symposium with invited experts to further develop relevant indicators; and
- developing a research strategy to test and monitor these indicators in the field.
Approach & Outcomes
Soil quality indicators are required for monitoring and maintaining sustainable agricultural systems. This research programme was conducted by a collaborative Working Party comprised of experts from AgResearch Ltd, Crop & Food Research Ltd, Landcare Research Ltd, Lincoln Ventures Ltd and Lincoln University.
An initial series of meetings was held to refine procedures and to develop a primary list of potentially useful soil quality indicators from a detailed review of the international literature. The Working Party then organised a two day international workshop on soil quality indicators which was held in February 1996 at Lincoln University. Soil scientists from the USA, Canada and the UK were invited to present plenary papers at the workshop and to help facilitate the sessions. Thirty New Zealand experts from universities, research organisations and from regional and national government agencies also attended the workshop. The aim of the workshop was to select soil quality indicators that showed promise for their usefulness and applicability for New Zealand conditions. The proceedings of the workshop formed the base of the final report.
For the purposes of this programme "soil quality" was interpreted simply as "fitness for use" in order to focus on the development of indicators for assessing the long-term sustainability of New Zealand’s agricultural production systems. Nevertheless, in some cases on-site measurements may also be useful indicators of potential off-site problems.
Soil quality indicators were examined in four main workshop sessions: these covered criteria for selection of an indicator, soil physical indicators, chemical indicators, and biological indicators. The outputs from each workshop session were further refined by the Working Party in order to select those indicators that showed the greatest potential for use in New Zealand.
The workshop session on criteria established that soil quality indicators should be:
- scientifically valid;
- cost-effective and relatively easy to measure and understand;
- accessible to both the specialist and the farmer;
- where possible, a component of an existing data set;
- sensitive to variations in management;
- predictable in their influence on plant and animal health;
- strongly correlated with agricultural ecosystem processes;
- internationally acceptable; and
- able to support policy relevant to sustainable agriculture in New Zealand.
Clearly few, if any, indicators will fit all the criteria, and the criteria will vary depending on the type of monitoring and management system being used. Nevertheless, application of the criteria helped to refine the selection of indicators from over forty to the list presented below.
The soil physical indicators identified as potentially useful were:
- soil aggregate size and stability, particularly in cropping soils;
- infiltration rate and hydraulic conductivity, particularly in pasture soils;
- visual assessment of soil surface and/or soil profile, especially to detect compaction and erosion;
- measurement of 137Cs as an indicator of surface erosion; and
- minimum data sets should also contain texture and waterholding capacity as fundamental soil physical properties.
The chemical indicators identified were:
- soil pH and plant available nutrients (especially P and K); total organic C and N, cation exchange capacity (CEC), and anion retention, as fundamental properties;
- specific chemical indicators, such as heavy metals, pesticides, and salinity are useful where soil contamination is a problem; and
- components of soil organic matter (as discussed further under biological properties).
While biological processes are acknowledged to play major roles in soil quality, there appears to be little agreement on satisfactory indicators of biological quality.
The following indicators were provisionally identified:
- microbial biomass C (Cmic), particularly useful in cropping soils;
- microbial quotients (Cmic/Ctot) (i.e. the ratio of microbial biomass carbon to total organic carbon);
- metabolic quotients (qCO2) (i.e. the ratio of carbon dioxide respired to microbial biomass carbon);
- potentially mineralisable N; and
- number and types of earthworms.
Researchers concluded that the programme identified an initial range of potentially useful indicators for assessing the sustainability of agriculture in New Zealand. It was emphasised that the knowledge base in this area is expanding rapidly and therefore that this list is by no means exhaustive or final. The results of research programmes being conducted by a variety of organisations in New Zealand and overseas may change the range of indicators that should be used.
Evaluation of the indicators is being carried out in the 1996/97 programme.
Contact for Enquiries
Farm Monitoring Programme Manager
Monitoring and Evaluation
MAF Policy
PO Box 2526
Wellington
NEW ZEALAND
Phone: +64 4 894 0623
Fax: +64 4 894 0741
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