OverseerFM assumes that the data entered is a real and reasonable representation of a farming system; which means that the production data entered is in equilibrium with the nutrients brought into and generated on the farm. Each farm is different, and management can have a significant impact on production levels and so the model does not dictate what it considers real.
The implication of this is that you need to enter either observed production if describing an existing system (Year-End Analysis) or reasonable production if describing a potential future system. The physical characteristics of the Farm (soil, topography, climate, distance from coast) should be fixed for the farm and only change when land is included or excluded in an analysis.
Where a Year-End analysis is being created, evidence may be required by auditors for the data entered. As OverseerFM runs a long-term climate model (providing a "typical" climate baseline for the farm), information entered should reflect the "typical" management approach taken on farm. This can be an average of multiple years management and the evidence will need to reflect this.
Please note, while there is limited detailed quantitative assessment of the impact on the results of using annual management information we do know that irrigation should not be entered as an amount of water applied in a particular year, as this is not consistent with the background climate model. Instead the management approach used should be entered.
Audit Tip 1: Irrigation
Check if the information in OverseerFM reflect irrigation systems and approaches not an attempt to enter the actual amount of water applied.
The best way to think about how to demonstrate your current typical farm nutrient management system in OverseerFM is to think about how you would describe your farming approach.
Audit tips 2: Comparative assessment
The Overseer science model is designed to provide a comparative assessment of a farm system over the long term. This means that:
- Exact activities in a single year that are the result of extreme weather conditions or part of a conversion of a farm system cannot be used to generate a meaningful analysis.
- In terms of animal numbers, approximation of enterprise and mobs is enough i.e. a detailed stock reconciliation is not required. For farm systems which have multiple smaller movement events (those with few animals) these can be rolled up into a single event with a date that allocates the average for the month
More information about how OverseerFM uses the stock numbers entered can be found here
To enter an accurate and defensible system the following information is recommended.
- Maps showing
- Location of owned land, farmed land and any leased land
- Topographies (flat, rolling, easy, steep)
- Location and area (ha) of each type of Irrigation system
- Location of soil moisture monitoring equipment (probes/tapes)
- Location of Effluent areas (where solids are applied and where liquids are applied)
- Location of crops grown and grazed/harvested (Paddock numbers)
- For the current 12 months and the 12 months previous.
- For the current 12 months and the 12 months previous.
- Mole/tile drain location on farm
- Percentage of block areas drained
- Total area of similar wetlands (including the location marked on a map)
- Total length of Grass filter strips (including the location marked on a map)
- Land Cover – to determine block type
- Pasture (including Lucerne)
- Permanent fruit trees/vines
- Fenced riparian or wetlands
- Outdoor pig areas
- Type - fodder, forage, grain, seed, vegetable or green manure
- Crop yields
- Management including; 24 month rotation sequence, timing of sowing, cultivation practices grazing/harvesting practices and residual management.
- Destination of forager crops at harvest
- Grazing/cropping history
- Stock – for each line of stock e.g. MA Cows, R2, R1, spring calvers/autumn calvers etc.
- Replacement rate
- Numbers by month
- Weights at start and finish of periods
- Age at start and finish of period
- Lambing, calving, kidding, fawning timing and percentages
- Timing of sales and purchases (for finishing farms, this is most easily reflected in monthly totals)
- If a class of stock is kept to a specific area of the farm, where is that?
- Total kg Milk solids
- Total kg/yr wool weight
- Total kg/yr Velvet & Antlers
- Total kg/yr crop yield
- Effluent System (if applicable)
- Type (spray form sump, holding pond, solids separated)
- Rate of applications
- Information on both solids and liquid effluent applications.
- Structure (Animals may spend time on structures such as feed pads, wintering pads or in milk sheds. These structures define the time animals spend there, the food eaten and how effluent is collected.)
- Bunker lining
- Effluent management - is it separate
- Time on structure (hours per day)
- Percentage of herd on structure
- Imported (type and amount)
- Exported (type and amount)
- Grown and stored on Farm (type and amount - including typical timing of storage)
- Where they are made on farm
- Fed (location and timing of feeding)
- Product applied
- Month of application
- Location applied (including differentiating applications to crops, fodder crops and pasture)
- Application rates (effluent versus non effluent versus dryland)
- Irrigation (if applicable)
- Type and management practice (application depth (mm) and return time (days) for each system
- If irrigation applicators are scheduled based on soil moisture information, trigger points used as mm deficit or % PAW
OverseerFM connects farms to science to allow rural professional to support farmers in developing informed farm plans, that enable farmers to improve their farm sustainability.
Additional tips for consultants can be found here