Fire Recovery

Question 1

5 factors to consider before attempting to recover pastures after fire damage.

Answer 1

1. Remove stock + wait for significant rainfall to see which pastures recover
2. Allow burnt pastures sufficient rest before grazing
3. Improve existing pastures through grazing management, fertiliser application and weed control.
4. Use fodder crops for quick feed
5. Plan and prepare before re-sowing perennial pastures.

Question 2

A moderate intensity fire burns;

Answer 2

Dead plant material, some seed and young perennial grasses.

Question 3

A high/hot intensity fire/burn destroys:

Answer 3

All dead plant material, young perennial grasses and those weakened by drought, anual grasses.

Question 4

Plants that may survive a hot burn:

Answer 4

Well established perennial plants with low crowns and deep roots.

Question 5

Very hot burn destroys:

Answer 5

All plant material and seeds, soil surface is sterilised. Surface soil organic matter is incinerated. Soil is baked.

Question 6

Plants that survive a moderate intensity burn?

Answer 6

Established perennial grasses, some well established summer anual grasses can survive.

Question 7

Temperatures below the surface of the soil is usually not changed drastically. This suggests;

Answer 7

That plants that bury their seed such as sub clover or that have growing points below the surface such as many perannial grasses, will survive.

Question 8

The effect of fire varies with:

Answer 8

Pasture species type, pasture health and seasonal conditions leading up to the fire event.

Question 9

Well Established Australian Phalaris fire survival;

Answer 9

Extremely good fire survival/tolerance. Phalaris produces storage roots and has a deep rooting habit making recovery usually possible. Varieties such as Atlas, Holdfast, land master are more prone due to their upright erect habit.

Question 10

Cocksfoot susceptibility to fire?

Answer 10

Cocksfoot is semi-shallow rooted. When fire moves quickly, cocksfoot recovery is much more satisfactory than prolonged with high levels of dry material present, recovery is poor. Erect crowned varieties will be more impacted.

Question 11

Perennial ryegrass susceptibility

Answer 11

Most fire susceptible improved temperate grass species. Extent of losses will depend on speed and intensity of the fire.

Question 12

Tropical perennial grasses fire susceptibility

Answer 12

Generally good tolerance. Rhodes grass, rhizomes

Question 13

Kikuyu fire susceptibility/tolerance

Answer 13

Kikuyu is generally the first species to regenerate following post fire rainfall. Below ground rhizomes enable kikuyu to regenerate following rainfall. Await kikuyu until the 4 leaf stage before grazing to improve recovery.

Question 14

Affect of fire on subterranean clover

Answer 14

Is often not usually affected by fire.
It has usually set seed before onset of the fire season. Sub clover seed in soil is stimulated to germinate following fire.

Question 15

Lucerne recovery and susceptibility after fire?

Answer 15

Survival of well established lucerne with a long taproot is often high following a fire.

Question 16

Soil type and recovery after fire, lighter sandy soils?

Answer 16

Tend to have a slower recovery than heavy soils.

Question 17

Soil type and recovery after fire, clay/heavy soils?

Answer 17

Tend to have a faster recovery than lighter soils. Soils high in organic carbon and highly fertile will have the best chance of a speedy recovery.

Question 18

Fire and phosphate

Answer 18

Fire has little impact on soil phosphate reserves. Small amount of phosphate in the ash will wash through in the next rain and become available for plant uptake.

Question 19

Fire impacting nitrogen levels.

Answer 19

Fire destroys topsoil organic matter reserves and the nitrogen within it is lost. Loss of topsoil nitrogen can result in poor pasture grass growth following a fire.

Question 20

Main nutrient losses from a fire are caused by?

Answer 20

Erosion of topsoil.

Question 21

Soil pH is predominately….. post fire

Answer 21

Unchanged.

Question 22

After fire organic carbon levels:

Answer 22

decrease variably but often 10%.

Question 23

Any conservation works such as rip lines or cultivation should be done in consultation with ?

Answer 23

A soil engineer

Question 24

Summer forages

Answer 24

Millet, dolichos, cowpeas

Question 25

Winter forages

Answer 25

Oats, ryegrass, wheat, barley, triticale, buckwheat.

Question 26

Re-sowing perennial pastures

Answer 26

Good planning and preparation should be made before sowing a perennial.
Annual fodder crops for two or three years prior, assists in weed control.
Consider the delay of sowing until late autumn or winter to allow for good weed control.

Question 27

What perennial weeds can survive hot burns?

Answer 27

Serrated tussock, POA tussock, coolatai, African love grass, dock and sorrel will survive even hot burns.

Question 28

Fire stimulated weed seeds:

Answer 28

Capeweed, stalksbill, fireweed and Patterson’s curse

Question 29

How to get rid of annual grass weeds

Answer 29

Combination of winter cleaning and grazing / top spraying.

Question 30

What is winter cleaning a pasture?

Answer 30

Process of applying sims one being absorbed through the roots when plants are actively growing. The cleaning effect is amplified by a later second application of Paraguay of which damages the leaves.