Pasture assessment

Improving pasture use with regular assessment

You can only manage what you measure. Regular pasture assessment is important for pasture utilisation and will help answer the following:

• How much pasture have I got today?
• How much will I have next week?
• How big is the surplus or deficit?
• How much pasture remained when the cows left the paddock?

Assessing your farm's pasture regularly, using tools like feed wedges, spring rotation planners, or autumn planners depending on the season, gives you important information to make informed decisions around feeding and pasture management and helps you align the available pasture with what your herd needs.

Properly allocating pasture is crucial during the peak growing season to reach desired grazing residuals and avoid long-term consequences on pasture quality or persistence.

Pasture measurement

There are several ways that pastures can be assessed and measured. Some of the common methods are:

Calibrated eye or visual pasture assessment

This can be as goo as any tool but requires practice and calibration. Calibration can be achieved through regular farm walks with a farm consultant or the farm team, or through occasional comparison with a tool like the rising plate meter (RPM).

Rising plate meter (RPM)

The rising plate meter converts compressed pasture height into pasture mass using different seasonal calibration equations that are specific to the pasture type. See the table below for the calibration equations for different seasons.

C-Dax pasture meter

The C-Dax pasture meter (also known as the rapid pasture meter) is an electronic device towed behind a vehicle. It uses light beams and sensors to measure pasture height and converts the average pasture height to pasture mass using seasonal calibration equations.

New tools and technologies

Over the past decade there has been an increased focus on the development and use of precision technologies in agriculture. As a result, there are several new tools that can be used to estimate pasture mass. Some of these tools offer value beyond measuring pasture performance, such as decision support features, suggested paddocks to graze based on estimated pasture mass, or projected pasture mass surpluses and deficits.

Examples of these new tools and technologies include:

• LIC SPACE
• Pasture.io
• AIMER Vision
• Halter Pasture Pro
• Farmote

Pasture condition score tool

The pasture condition score tool is a visual assessment guide which provides an alternative way to compare paddocks for renewal or maintenance such as fertiliser and under or oversowing. Many pastures have less than desired density of ryegrass and clover because of treading damage in winter, insect damage, or drought during the previous summers.

Assessing the damage in each paddock by ranking them one to five based on visual scores, can help establish a plan for each paddock.

See the Pasture condition score guide.

Recording and decision support

Regular pasture assessment, which is well recorded in a notebook, spreadsheet or in a suitable computer program, can provide valuable information not only for short term decision making but also for future management decisions.

Regular pasture data can provide:

• Annual farm growth rates
• Individual paddock growth rates
• Seasonal average pasture cover targets.

This information can be used to build a feed wedge, increase accuracy in feed budgeting and to assess paddocks for renewal or development.

Helpful tools for pasture management:

• Use the Spring Rotation Planner online tool, or the manual Spring Rotation Planner from calving to balance date
• Use the feed wedge after balance date through to autumn.

There are a range of computer programs and software available through commercial suppliers aimed at helping make decisions from pasture data.