Maintaining profitability in agriculture
Changes in climate have and will continue to present challenges and opportunities for agricultural production in the Wimmera. The Wimmera farming community is renowned for its ability to innovate and adapt to its climate and market forces. This continual adaption and innovation has led to new crops and pastures, new varieties and changes to planting times and planting and management techniques. Many of these innovations are being driven by the agricultural industry and include plant breeding, chemical fertiliser development and machinery design.
Priorities for adapting to climate change for the Wimmera while maintaining profitability include:
Crop breeding and genetic modifications are potential solutions to these predicted impacts. Given limited funding there is a need to focus this effort into the most beneficial areas. Suggested crop breeding priorities may include:
Methods such as growing crops all year round and under sowing promote carbon being fixed into the soils for a longer period. Under sowing is the sowing of a secondary crop underneath the primary cash crop. For instance, a cereal can be undersown with green feed or pasture species which should be well established by the time the cereal is harvested in mid to late summer. This can be considered as an adaptation and mitigation action as it can increase the storage of carbon and nitrogen (mitigation) and can also create a diversity of income from crops or pasture at various times of year (adaptation).
With climate change predictions suggesting lower winter rain and higher summer rain for the Wimmera, opportunities may emerge to grow two crops per annum. For example, growing a legume, followed by a cereal, one at a traditional time (April/May) and the other immediately after harvest when and if summer rainfall occurs or opportunistically during wet late spring. This may be limited to higher rainfall areas or where available soil moisture is present. Examples include sorghum, maize, and corn. There are other potential species grown in others areas of Australia that may become suitable in a changing climate.
Clay topping or claying is a practice that has been utilised in the Wimmera for about 20 years and is known to increase productivity and yields in some soil types. Sandy soils have low fertility levels due to low cationic exchange capacity (CEC) and low levels of organic carbon. Raising the clay content changes soil texture, which increases the capacity for the soil to store water and nutrients, increase cationic exchange capacity and soil organic carbon. Given this activity is somewhat focused on soil moisture retention this could impact on water availability for waterways if not managed correctly.
Claying trials are being conducted by a number of soil agencies, across the Wimmera, in a range of locations with different soils
types and rainfall.
The focus on this section is to address the potential impacts from climate change on soil and pasture rather than animal husbandry and emissions. For example it does not deal with the potential impacts on animals from heat stress or parasites.
CSIRO suggest that some of the potential impacts of climate change on grazing are:
Community feedback has indicated that there is still much to learn and do to build the resilience of our grazing systems to cope with climate change. There are many theories about the potential impacts that the range of climate scenarios will have on grazing that require further investigation in real life situations.
C3 and C4 plants
Plants can be divided into different categories by the way in which they utilise carbon dioxide and their carbon fixation pathway and can be C3 or C4 or CAM (Crassulacean Acid metabolism) plants. Some research indicates C3 plants typically respond better to atmospheric CO2 enrichment than do C4 plants in terms of increasing their rates of photosynthesis and biomass
production. A warming climate is predicted to favour warm-season, or C4 grasses while rising CO2 should favour C3, or cool-season plants. Combined warming and CO2 enrichment stimulates above ground growth of C4 grasses most years when soil moisture most limits plant productivity.
There may be great opportunity for different C3, C4 or CAM pastures or fodder shrubs to be utilised as agricultural industries adapt to climate changes and the new and varied conditions. These plants may be annual or perennial and be grass, legume,
shrub or tree. More research and trials will need to occur to provide some certainty to land managers about the intricacies of
these theories and how pasture systems can be manipulated to deliver profitability.
Pasture breeding and genetic modification are potential solutions to the predicted impacts. Given limited funding there is a need to focus this effort into the most beneficial areas. The same logic for C3 and C4 plants can also be applied to weeds. Some weeds may become more vigorous meaning greater effort will be required for their control. Others may become climate stressed, providing an opportunity for greater control or eradication. This is discussed further in Section 2.5. The need for further research and trials has been highlighted as a high priority during stakeholder consultation.
Priority actions for research and trials for grazing include:
There was consensus, during stakeholder consultation, that landholders need to have access to information about practices
that can help them adapt their grazing systems to variations in the climate while remaining profitable. Priority extension activities include demonstrations and workshops on:
There is also a need to deliver information through a range of mechanisms including, media, consultants and other landholders.