It is that time of year again, storm season, adding even more challenges to the art of farming. At this time of year, it is more important than ever to be prepared for the worst and plan ahead.
You can get the latest weather forecast via the Bureau of Meteorology’s website or the BOM Weather app. This is also where you get severe weather warnings. On the website you can furthermore check seasonal outlooks, see the latest observations, and read about the different climate drivers and how they impact your local weather.
The La Niña declaration on 29 September 2020 is expected to bring above average rainfall across Queensland over late spring and summer. La Niña typically also leads to an increased number of cyclones and longer duration of heatwaves in the south east, although less intense. Increased cloud is another characteristic of La Niña, leading to lower maximum temperatures and higher overnight minimum temperatures.
To minimise damage from summer storms and severe weather it is advisable to clean up around the farm. If the farm is kept need and tidy, the usual storms should not cause damage and you are a step ahead if a severe weather warning is issued and further precautions are needed. It is especially important to keep fertilisers and chemicals safely stored, make room for farm machinery under cover in case of hail, keep gutters clean and clear old branches from trees close to infrastructure. It is also important to check the forecast before spraying and applying fertiliser, a heavy downpour later in the day might wash your hard work and money down the drain so to speak.
Erosion risk
Heavy rainfall can cause serious erosion so at this time of year it is even more important than usual to keep groundcover healthy across the farm and where possible, time rotation of annual crops to avoid bare fields.
The revised Universal Soil Loss Equation (RUSLE) maps below give a good indication of how important groundcover and bed direction is to keep soil in place.
The equation for RUSLE is
A = R*K*LS*C*P
Where-
A = estimated average soil loss in tonnes per hectare
R = rainfall erosivity factor
K = soil erodibility factor
LS = the topographic slope length and slope gradient
C = cover management factor
P = erosion control practice factor
RUSLE does not paint a full picture of erosion on farm, as an example it does not take into consideration deposition of sediment in traps or ponds before the water reaches a waterway. However, it is a projection tool of what can happen in the field, helping to identify high risk area. The below examples illustrate how two factors – ground cover and bed direction can greatly impact on erosion risk.
With the pink and red areas on the RUSLE maps being highly erosive while blue and green are low erosion risk areas Figure 1 and 2 illustrate how bed direction is very important when ground cover is low at 40 per cent. While figure 3 and 4 shows how the bed direction is less significant when ground cover is high. Comparing figure 1 and 3, and 2 and 4 respectively, illustrate how essential ground cover is to keep soil in place when bed directions are similar.
The recent years of dry conditions have made ground cover management more challenging with water sometimes, understandably prioritised for commercial crops. However, ground cover is an insurance for topsoil, helping to keep the soil in place and healthy for seasons and generations to come, careful considerations should therefore always be made to manage and nurse cover crops along with commercial crops.
Hort360 SEQ is funded by the Department of Environment and Science.
For more information or to book a property visit, please contact:
Rowena Beveridge
Hort360 SEQ Manager
0417 783 313
rbeveridge@growcom.com.au
Lene Knudsen
Hort360 Facilitator
0429 000 179
lknudsen@growcom.com.au