Reality Bites on the Monaro: A Winter Wake-up Call

by Stu Burge

July is the very heart of winter on the Monaro.

A month that livestock hate and landholder’s loveto escape …!

This winter is especially a reality check after the most amazing three consecutive wet, mild winters.

However, for those of us with experience of the Monaro this winter is far more typical of most (unfortunately) with ongoing lack of precipitation and a run of cold temperatures and frosts.

The reason for this sense of “reality” is demonstrated in the accompanying “screen shot” from ABC television taken on May 23 which has been repeated on many occasions this winter.

Here we see a frontal system sweeping across Australia bringing rain to much of south-eastern Australia west of the Divide but with a distinct absence on the Monaro and south coast.

This of course is no real surprise and simply demonstrates a typical orographic rainfall event whereby we miss out due to our proximity and location in the lee of the Snowy Mountains.

(Fortunately for the allimportant ski industry such moisture laden events usually bring much needed snow but alas under such conditions this dissipates before reaching the lower elevation grazing lands.

In practical terms it means that we are located in a “rain shadow”.

This rain-shadow is especially felt around Dalgety – BobundraBerridale and Cooma if we look at long term rainfall isohyets while the southern Monaro around Bombala and Delegate as well as higher elevation country to the east (Nimmitabel –Countegany – Jearangle) the influence tends to be less pronounced.

The practical significance of this is evident in the accompanying photograph(s) which clearly demonstrate the impact of this phenomenon on the grazing environment at present.

Here we see parched frosted pastures and declining levels of available green feed which reflect the inherent pasture growth rates at this time of the year.

July is the month of lowest pasture growth and is accordingly the bottom of the so-called “winter feed trough”.

Of course there is nothing we can directly do to affect rainfall nor influence winter temperatures. There are however a number of management factors that landholders can implement to modify these meteorological effects.

Maintaining organic matter via a layer of litter on the soil surface helps to modify the impacts of frost and low temperatures as well as maintaining soil moisture.

The “miracle of the litter mat” also contributes to the enhancement of a healthy soil through stimulating soil biology and soil microbes.

A more pronounced, interventionist and costly way by which Monaro landholders cope with the reality of winter and helping to address the winter period of least feed availability is to “grow more grass”.

This means the sowing of “improved pastures” and winter forage crops which have the capacity to exhibit higher growth rates during winter when compared to native species.

While native species provide the backbone of the grazing industries on the Monaro and provide stability in our grazing systems the downside is that they have much lower growth rates than those species which have been selected or bred for higher winter growth (as well as providing higher animal nutrition).

For example, as a broad guide, a totally unimproved “native pasture” with few or no introduced species and no fertilizer input will grow at 1-2 kg/ha/day during July.

By contrast an “improved pasture” with sown introduced species which receives a carefully planned fertiliser input to correct nutrient deficiencies has a potential July growth rate of 7-10 kg/ ha/day (depending upon rainfall and soil type).

For winter forage crops these can be much higher again depending upon time of sowing.

This transfers to a substantially higher stocking rate and therefore overall farm profitability.

This is not to say that every paddock should be sown to improved pastures but it highlights the need for balance and a wholeof-farm approach as the basis of a sustainable grazing system.