L.PDS.1803 - EPDS: Predicting spring pasture growth
Currently decisions to act and manage unknown and variable winter/spring pasture growth are made based on experience, best estimates given current dryness/wetness of soil, pasture condition and weather forecasts
| Project start date: | 30 April 2018 |
| Project end date: | 16 June 2023 |
| Publication date: | 30 April 2024 |
| Project status: | Completed |
| Livestock species: | Grass-fed Cattle, Sheep, Lamb |
| Relevant regions: | Victoria |
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Summary
Seasonal variability of pasture growth has increased across southeast Australia in recent decades. Previous research has indicated that soil water content in early spring is a good predictor of pasture growth over the following months, which is crucial to better management of variable seasons. However, this research has been based on biophysical models (to produce predictive tools like AskBill and MLA Rainfall to Pasture tool) but is yet to be validated with real time data for farmers to have confidence to make changes. Farmers and consultants are looking at the probe data for direction on decisions based on soil temperature and the potential to boost winter growth, and how full the soil profile is for potential pasture growth. The knowledge to interpret these predictions could enable early management decisions to either reduce the impact of poor spring pasture growth or optimize the utilization of good springs.
Objectives
The main objectives of the project were to:
• model and validate spring pasture production in four paddocks that have soil moisture probes installed, over three successive springs (2019; 2020 and 2021)
• demonstrate and promote the value of soil probe data in the local area for management decisions
• improve management of spring pastures through facilitated farm walks and discussions
Key findings
Due to full soil moisture profiles at all sites at the beginning of spring in all years, pasture predictions indicated average to above average spring pasture growth. Coupled with above average spring season climate forecasts in 2020 and 2021, an increase in the amount of feed was predicted and/or an increase in the length of the growing season. This was validated by actual cuts where possible, particularly in year three (2021).
A cost: benefit analysis was therefore not undertaken due to the good seasons over the project; limiting the ability to make and estimate any cost saving decisions. Whilst good spring conditions were predicted, none of the site hosts indicated any early decision making due to this (e.g., cutting hay or silage) but all aimed to utilise the feed with existing stock. Management changes identified by farmers involved for using the soil probe data in the future (particularly in the event of a poor forecast) included: stocking rate decisions; buying and selling of stock; fodder purchases and pasture sowing decisions. The cost: benefit from this range of decisions and cost; price range scenarios was too large an analysis for this project.
The results of the demonstration have increased the access and use of soil probe information for farmers involved (and potentially the wider service provider industry) for decision making in relation to both temperature (pasture sowing and winter boosting) and soil moisture (early spring warning and pasture sowing) so farmers and consultants involved are more likely to use the site for these decisions. Agriculture Victoria will use this information to target newsletter/warnings through its networks at more specific times as indicated by farmers involved. The confidence in the predictions will also likely provide more impetus for farmers involved (and outside the core group through the communications) to try and use future dashboards or software that do this.
Benefits to industry
The project highlighted the value that soil moisture probes can have in decision making in early spring for stock and feed decisions but also for pasture sowing decisions throughout the year. Engagement with producers at some level may be crucial to ensure confidence in the technology.
Given the increasing installation of soil moisture probes across the state, this project has provided more guidance on how they can be used to assist farmers in their farm management decisions.
MLA action
MLA continues to deliver the Producer Demonstration Site (PDS) program, supporting livestock producers working in peer-to-peer groups to pursue new skills, knowledge and management practices applicable to their own commercial livestock production systems.
Future research
Extension is still required about of the benefits of knowing local pasture growth rates and potential pasture production so that the value of increasing production can be understood (e.g., cost benefit of changing pasture species; pasture boosting fertilisers; grazing management etc.
There is interest in the platforms and technologies that are available and emerging for assessing pasture availability and growth rates so there is a need for extension and evaluation of these so that farmers can adopt and use with confidence. There are currently no simple predictive pasture growth tools available in Victoria. For example, the Farming Forecaster platform developed in NSW provides similar predictive information with a simple dashboard and is currently available in NSW and some parts of Tasmania and Western Australia. Farmer discussions and validation is considered to be critical for wider confidence and uptake of tools if and when they develop.
Assisting farmers to set some relevant trigger dates and guidelines for early decisions relevant to their operation, will be critical to adoption in the future.
More information
| Project manager: | Alana McEwan |
| Contact email: | reports@mla.com.au |
| Primary researcher: | Department of Energy Env & Climate |
