Wet season spelling

Why spell pastures?

Beef cattle enterprises in north Queensland rely heavily on 3P (perennial, palatable and productive) native pastures for production. Continuous grazing over several years places pressure on preferred pasture species and 3P pastures may be at risk of being grazed out and replaced with less palatable grasses or weeds. Degraded pastures negatively impact animal performance. Wet season spelling (removing cattle during the growing season), supported by safe stocking rates can help restore degraded paddocks and increase animal productivity.

A spell should start at the beginning of the growing season and last long enough for grasses to set seed. By seed set, providing there has been adequate rainfall that season, there should have been sufficient transfer of nutrients to the roots for recovery and growth in the next wet season. It is important that 3P grasses set seed in most years to maintain productivity, maximise tussock survival in dry years and to increase 3P seed reserves in the soil.

Leading beef producers in northern Australia use wet season spelling as part of an integrated property management plan. Werrington Station, north of Hughenden, is a grass-fed beef operation comprising of 19,500 hectares of predominantly native pasture. The owners of Werrington Station, the Lethbridge family, use wet season spelling as a pasture management tool, spelling a third of their country annually during the wet season. Russell Lethbridge says ‘Heavily grazed paddocks will not respond well to rain and this reduces the annual land condition and carrying capacity.’ Russell believes that wet season spelling provides ‘good buffers in ground cover and pasture quality, which means that Werrington’s overall management does not have to change dramatically regardless of what the season brings.’

To read more about the Werrington approach, read the case study provided by GrazingFutures: Werrington Station — ‘Hope is not a plan’.

The theory behind the practise

‘The early part of the wet season is the most critical time to spell. Tussock grasses are very vulnerable to grazing in the first 6–8 weeks of the growing season because they have to use up some of their root reserves to produce green leaf’ – Dr Dionne Walsh, Rangeland Program Manager, NT Department of Primary Industry and Resources (read the original article here). During the early ‘green pick’ stage of growth tussock grasses rely on their root nutrient reserves to produce green leaf following early season rainfall. Spelling allows pastures the opportunity to replenish root reserves, maximise seed production and hasten seedling establishment across the pasture system. Pastures that are given the opportunity to grow without being grazed for the first 6–8 weeks of the growing season are more robust and have more bulk (Figure 1).

Brahman heifers in forward store condition standing in a paddock of dense Mitchell grass pastures after a wet season spell.
Figure 1. Good numbers of 3P pasture species following a wet season spell period on a Queensland Gulf property.

 

In the Georgetown region of the Queensland Gulf, Glen and Cheryl Connolly are advocates of wet season spelling. Since purchasing Blanncourt (a breeding enterprise of 18,739 ha) 20 years ago, the Connolly family have improved both productivity and profitability by implementing lighter stocking rates, wet season spelling, feeding and/or supplementation programs, cross breeding and pasture improvement.

The Connelly’s have a number of property management principles that they implement, with a major management tool being wet season spelling. Effective spelling practices enable the Connelly’s to use spelled country for cattle with the highest nutritional requirements. Weaner paddocks are always spelled every wet season to provide fresh paddocks for newly weaned calves. Regular spelled paddocks are prioritised for wet cows with a branded calf.

To read more about Blanncourt, read the case study provided by GrazingFutures: Blanncourt Station — productivity and profitability gains through efficient herd management

How long to spell

For some paddocks a short spell for 6–8 weeks in the wet season is plenty to recharge productivity. Severely run-down pastures with little left of their 3P component, will require whole of wet season spelling over several seasons. Depending on location, removing cattle following second round mustering (September) might be the most practical way to ensure a full wet season spell in run-down paddocks, although some properties can easily shift cattle up until the break of season has occurred. Making a decision to destock a paddock in the dry season should also be about retaining healthy ground cover and stubble to minimise runoff and maximise pasture response to first storms. Pastures in overgrazed and bare paddocks respond very slowly to rain.

Several decades of continuous and heavy stocking on many northern beef enterprises have slowly wound down 3P pasture populations, 3P seed reserves in the soil, pasture productivity and overall carrying capacity. Likewise this decline will not be addressed overnight by a wet season spelling program and lighter stocking rates. Rangeland condition decline is slow to turn around with many producers reporting a decade is often required to restore productivity on poor condition country. Some paddocks will require an annual wet season spell for successive years to restore 3P grasses.

 Getting stocking rates right

To maximise success of the wet season spell, stocking rates should be aligned with the long term carrying capacity of the paddock and the seasonal conditions. Continuing to run high stocking rates will overgraze stocked paddocks and defeats the purpose of spelling. Have a planned approach to wet season spelling. Spelling 20-25% of your property annually will help ensure a solid feed supply is available for cattle and also provides a feed buffer during the low rainfall years we regularly encounter.

At Blanncourt, the Connelly’s have the following “Rules of Thumb” regarding wet season spelling:

  • ‘Don’t be disillusioned when the pasture response to wet season spelling is slow in the dry years. If some country is spelled every year you will eventually get under a good season, and pastures will respond.’
  • ‘Identify paddocks in poor condition then wet season spell every year until pasture condition turns around.’
  • ‘Have you got the ability to systematically lock up 25% of your property over the wet season? If not, your stocking rates are too high. Each paddock on Blanncourt receives a wet season spell every 2–4 years, however all weaner paddocks are spelled annually.’

More information

For assistance in determining your property’s long term carrying capacity, forage budgeting or to discuss the best strategy for wet season spelling, get in touch with your local Beef Extension Officers.

This article has been written by Megan Munchenberg and Lindsey Perry, Beef Extension Officers, Queensland Department of Agriculture and Fisheries.