image
Corangamite Region   'Brown Book'   - How to optimise your soils to enhance productivity
What can I do about my bare paddocks during summer or in drought conditions?
Most relevant to grazing and cropping industries
Understanding the problem
Managing the problem
Other related questions in the Brown Book
Resources
References

Source: DEPI Victoria
Understanding the problem
Why is it important to me as a farmer?
  • Potential for wind and water erosion
  • 1 mm of topsoil lost by erosion equals about 10 tonnes of soil per hectare
  • Not making best use of summer rainfall
  • Non-productive use of land
  • Invasion of weeds


Top of Page

How and why it occurs
  • In dry periods, soils become more susceptible to wind and water erosion as a result of the removal of the protective vegetative soil cover
  • This is caused by stock grazing and the trampling of the soil surface degrading the soil structure
  • Grazing stock may also cause irreparable damage to perennial pastures if the grazing pressure is too hard. Stock, under low feed conditions will also strip a majority of the stored annual pasture seed supply in the soil
  • Loss of cover in dry times is often an issue where there is a dominance of annual plant species over perennials
Top of Page

How to recognise it in the paddock
  • Bare paddocks are defined for this region by the following percentage of ground cover:
    • A minimum of 70% groundcover is the accepted benchmark for the high rainfall zone (>550mm) except for sloping country where higher than 90% ground cover is needed
  • See photographs in Figures 1-4 below depicting groud cover percentages
Top of Page


Managing the problem
What is the best practice?

  • The problems of degrading paddocks and long term decreases in productivity during drought are considerable, however a number of strategic management options can be put in place to minimize potential damage and give the paddock the greatest potential to recover rapidly and fully after rain
  • Essentially, the strategy aims to maintain a protective vegetative cover of the soil surface or groundcover. The vegetative cover can be living plant material, failed crops, crop stubbles or pasture residues
Top of Page

How can you achieve this?
Measure groundcover – do this irrespective of whether you are operating a grazing or cropping enterprise:
  • Note that in this region, a minimum of 70% groundcover is the accepted benchmark for the high rainfall zone except for sloping country where close to 100% is needed:
    • Visualise a 50 cm by 50 cm square or make one out of wire
    • For each paddock, record groundcover at about 30 random locations, look at the variation (highest and lowest values) and calculate the average
    • Look for more visual signs of erosion and soil loss such as gullies, rills and tunnelling, washing of soil, dung and litter along fence lines and around plants, muddy and silted dams and muddy streams with high sediment load
    • Monitor groundcover and grazing activity regularly to assess progress . Use the following photos as a guide to the amount of ground cover in your paddocks:

Figure 1 - 20% ground cover

Figure 2 – 40% ground cover

Figure 3 - 70% ground cover

Figure 4 – 90% ground cover
Photos source: Greg Lodge, NSW DPI
Top of Page

1. Pastures:

Reduce grazing pressures on pastures where groundcover is below acceptable levels:
  • Remove stock from paddocks once the pasture falls below the following triggers
    • >70% ground cover on flat country
    • < 90% ground cover on hilly country
    • Or <800kg DM/ha
  • Reduce stock numbers prior to summer (e.g. sell lambs)
    • Use the Meat and Livestock Australia Stocking Rate Calculator
  • Match the feed supply more closely to livestock
    • e.g. choice of calving or lambing time which influences how well livestock
    • feed nutritional demands match pasture availability
    • Use Evergraze pasture growth calculator
  • Establish stock containment areas:
    • What is a stock containment area?
      • A carefully selected part of the property which is set up to hold, feed and water core farm-stock during adverse weather periods
      • It should be considered as part of the property management plan and once established should be maintained and be available for use during emergencies
    • Benefits:
      • Protection of vegetative cover on majority of property
      • Less stress on flora and fauna values of the property
      • Facilitation of stock feeding, watering, monitoring and handling
      • Control of shelter and shade
      • Better control of weed contamination associated with imported feed

    Figure 5 - Stock Containment Area. - Source: DEPI, Victoria
    • Use sacrifice areas – areas where pasture was unimproved or is planned for improvement and can feed in these areas
    • Plant lucerne or summer fodder crop or summer active species suitable to climate and soil conditions to provide feed in summer

    Figure 6 - Lucerne. - Source: DPI, NSW
Pasture responses in perennial and annual pastures after dry periods:
  • Perennial pastures if managed properly through dry periods will be the first to respond following breaking rains to provide feed. If not managed properly however, the cost of repairing or resowing perennial pastures will be high
  • Annual pastures may need to be resown with a subsequent lag in providing feed following breaking rain. Fertiliser rates could be reduced at sowing due to low nutrient use by previous pasture
Top of Page

2. Crops
  • It is important to maintain cover on all cropping paddocks
  • Crops that have failed should not be grazed due to the limited quantity of vegetative cover they will offer the soil. Valuable nutrients will also be removed from cropping paddocks by grazing of failed crops
  • In addition, standing anchored crops or stubble provide more protection than flat crops
  • Field pea and lupin crops will offer very little protection unless they remain standing and therefore should not be grazed
  • Crops that have been stripped need to have the quantity of stubble remaining assessed to determine the extent of grazing before the risk of unacceptable damage will become too great. This will depend upon soil type, location and whether the stubble is standing or flat

  • The burning of stubble should be avoided and cultivation of soils, particularly light textured soils (sandy), should be avoided unless no cover remains
  • If no soil cover remains, emergency measures such as ripping may work on heavier soils however, ridging on lighter soils has limited success in preventing erosion
  • Soils whether light or heavy have a much greater ability to resist erosive forces by wind or water if vegetative cover remains with minimal trampling by stock
Top of Page

Other related questions in the Brown Book


Brown Book content has been based on published information listed in the Resources and References sections below

Resources
References
  • Lisa Miller– pers. comm. DPI Geelong.
  • Making More From Sheep. Module 6: Health Soils - Australian Wool Innovation (AWI) and Meat and Livestock Australia (MLA).
  • Paddock protection and stock management during dry times. Department of Primary Industries, Victoria.
  • Stock Containment Areas. Department of Primary Industries, Victoria.
Top of Page
This project is supported by the Corangamite Catchment Management Authority, through funding from the Australian Government’s Caring for our Country

Page Updated: September 2013
Produced by AS Miner Geotechnical