GrassGro: analysing grazing systems

GrassGro: analysing grazing systems

GrassGro is a decision support tool developed by CSIRO Plant Industry to examine variability in pasture and animal production and assist decision-making in sheep and beef enterprises.

Matching management goals with land capability

By testing management options against a wide range of seasons, farmers and natural resource managers can achieve more profitable and sustainable utilisation of grasslands to fit the unique combination of weather, soils, pastures and livestock at a particular location.

GrassGro helps analyse profit, risk and sustainable use of resources in temperate grazing systems.

GrassGro is a uniquely flexible and powerful tool that can be applied to a broad range of issues in agriculture and natural resource management at both farm and regional scale:

• Assessment of land capability and production benchmarking
• Resource sustainability: ground cover, water balance, nutrient deficiency
• Drought management
• Testing the suitability of pasture types, animal bloodlines and enterprises at a location
• Testing strategic and tactical decisions before committing funds: lambing and calving dates, supplementary feed policy, market specifications for livestock and more
• Supply chain analysis

WHAT IS GrassGro?

GrassGro is a computer program that delivers grazing systems research in a useable form to farmers and their advisers. GrassGro incorporates decades of field experimentation from across Australia and lets the user focus on the management decisions at a selected site.

Behind GrassGro's interface, inputs of historical daily weather data drive models of the interacting processes of pasture growth and animal production. Day-to-day changes in water content of soil, pasture growth and decay and responses to grazing are simulated for a chosen enterprise.

The user enters a description of livestock, their management and costs and prices. The GrazPlan animal model, familiar to users of the decision support tool GrazFeed, is built into GrassGro to predict animal intake and production of wool, meat and milk.

GrassGro helps assess productivity, profitability and risks that climate variability imposes on a grazing system. Seasonal and year-to-year variation in animal production and gross margins are presented in graphs and tables for analysis of risk.

ADOPTION

Since its release in 1997, GrassGro has been adopted by agricultural advisers, researchers, tertiary educators and policy makers.

GrassGro analyses are typically interpreted and disseminated to farmers by advisers, both private and within state government departments.

Over 100 licensed copies of GrassGro, with a comprehensive training package, have been sold to users in the temperate regions of southern Australia.

Teaching

GrassGro is used by the University of New England, to deliver innovative undergraduate programs in Rural Science to integrate specialist areas in animal science, agronomy, soil science and economics and to develop systems thinking in agricultural and natural ecosystems studies.

Support from Australian Wool Innovation has helped expand the UNE teaching program to other universities using web-based delivery of GrassGro and course materials. Students have found GrassGro to be an ideal teaching aid.

A Canadian version of GrassGro has also been developed for tertiary teaching at the University of Saskatchewan.

USING GrassGro

Users describe each component of the grazing system, drawing where possible on databases built in to GrassGro. Daily weather inputs for the selected location are obtained from the Australian Bureau of Meteorology database.

The soil profile is described by the user in terms of its water holding capacity. Soil physical properties, which are hard to measure, are can be obtained from default values derived from the National Soils database.

The user chooses the combination of legumes and grasses from a list of temperate pasture species and cultivars. The pasture can be simulated as an ungrazed paddock or grazed by one of the following sheep or cattle enterprises:

• Ewe breeding flock for meat, wool or dual purpose
• Wether flock
• Prime lamb production
• Fattening enterprises for steers or bull beef
• Beef breeding herd producing vealers, weaners, yearlings or bullocks
• Opportunity feedlotting

GrassGro is suitable for any breed of sheep or cattle. The user sets costs and prices and management rules for each enterprise, for example, the time of mating and initiation of supplementary feeding.

More than one paddock can be simulated at a time, in which case the user determines when different classes of livestock graze each paddock.

A wide range of output treatments and presentations as graphs and tables permit powerful analysis of each part of the grazing system.

A gross margin table shows the financial performance of the whole enterprise and sensitivity analysis to costs and prices can be quickly determined.

An extensive online Help facility guides the user in the practical application of the tool and provides background information on the biological models that GrassGro uses to make its predictions.

APPLICATIONS

GrassGro's flexibility makes it applicable to a wide range of grazing industry issues, both on-farm and beyond.

Farm management advice: helping solve practical problems for an individual farm or district

Long term decisions:

• What is the best long term stocking rate?
• What is the best time to calve or lamb?
• Should I run a different bloodline of sheep?
• In how many years will need to supplement stock?

Short term decisions:

• Drought management: How much feed should I buy?
• What is the chance that these animals will meet market weights?

Agricultural business and finance:

• Supply chain management across a range of environments
• Establishing risk for contracts

Research: animal and pasture science and agricultural economics

Education: a new approach in teaching systems thinking in agricultural science

Policy-making: modelling for drought, dryland salinity, greenhouse gas emissions, grassland fire risk, food sources for mouse plagues

END USERS

The role of the user is important: a GrassGro analysis depends on accurate description of the site and the user's ability to interpret and apply the outputs to a particular issue.

A typical GrassGro analysis enables the user to explore interactions between a grassland ecosystem and its management and should be used as a tool to support rather than make decisions.

Training

To get the most out of GrassGro, training is essential. Training aims to improve the user's level of understanding and application of the tool, and, importantly, to appreciate any limitations imposed by gaps in our scientific knowledge of the grazing system simulated.

Technical support

GrassGro users have ready access to technical support from the software development team. For example, weather localities for alternative sites can be obtained on request.

Feedback from users has been important in developing further releases of GrassGro that incorporate new science.

Ongoing development

To broaden the range of environments in which GrassGro can be applied, descriptions of new plant species are released as they become available.

This is a major scientific undertaking that incorporates the latest published information on the interactions between a plant genotype, the animals grazing it and the environment.

As a result GrassGro requires no 'tuning' but users need to consider appropriate species and management when describing a grassland ecosystem.

For information on pricing and purchase, contact Horizon Agriculture.

Horizon Agriculture
www.hzn.com.au/grassgro.php
Email: horizonag@hzn.com.au
Phone: 02 9440 8088
Fax: 02 9887 4428

Printable brochure on GrassGro (PDF)

For more information on GrassGro, contact Libby Salmon on 02 6246 5417.