Australian Agriculture Assessment 2001 - The changing face of agriculture
SUMMARY
- Land use and farming systems continue to evolve and diversify responding to commodity prices, market arrangements and natural resource conditions and opportunities.
- Livestock industries have reached a plateau. Areas under cotton, sugar cane, potato, rice and horticulture have all increased since 1983. Viticulture is also expanding in many regions.
- Farm numbers have decreased from 178 000 in 1982 to 145 000 agricultural holdings in 1996/97. Average property size has increased in the cropping and grazing industries.
- Between 1982 and 1997, cereal grain yields per hectare have improved in many regions, notably where crops are more diversified in regions of more reliable rainfall. Elsewhere, yield trends have been less spectacular. Improved nitrogen management was associated with strong productivity gains in several regions.
- Annual variations in yields of Australia's dominant crop - wheat - due to climate have reduced through development of drought-tolerant species and disease control.
- The area of irrigated agricultural land in Australia have increased by 26% in the last 20 years. Two-thirds of all irrigated land is in the Murray-Darling Basin; nearly half is used for pasture. Irrigated areas Australia-wide under cotton, sugar cane, pasture and fruit increased.
INTRODUCTION
Demand from domestic and export food and fibre markets for high quality products is a continuing challenge facing modern farming systems:
- Market signals - linking processes from 'paddock to plate' - are beginning to influence international trade in agricultural goods.
- Accreditation for the use of ecologically sustainable production systems is also increasing.
Contemporary Australian agricultural industries are seeking new opportunities while attempting to minimise impacts on the natural resource base.
In this analysis, data from the annual Australian Bureau of Statistics agricultural census were assembled for the years 1982/83 through to 1996/97 and used to map and interpret regional changes in land use at statistical local area scale in Australia's agricultural zone. All data were adjusted to accord with the 1996/97 statistical local area boundaries.
LAND USE CHANGE IN AUSTRALIAN AGRICULTURE
Australian agriculture has gone through phases of exploitation and expansion, adopted new technologies and dealt with issues such as pest invasions over the last century. The result has been steady growth in some land uses and productivity.
The decision to change land use is generally taken by an individual producer. Such a decision will have wide-ranging ramifications:
- increased capital expenditure;
- learning new farming skills and markets;
- reduced production for certain commodities and (if land remains in agriculture) increased production of other commodities for the region; and
- identifying new risks (e.g. income uncertainty).
At the regional or State scale, changes in land use reflect decisions by many individuals that, when added together, affect the patterns of agricultural activities, transport, food processing, employment and economics across a landscape.
Examples of land use change include:
- converting naturalised pasture to sown pasture;
- diversifying the range of crops grown;
- changing from grazing to viticulture;
- substituting wool production for beef or prime lamb production;
- sale of land for urban or hobby farm development;
- converting cleared land to farm and plantation forestry; and
- introducing irrigation where previously dryland enterprises existed.
Driver for change
Fluctuating prices for commodities, particularly over extended periods, (Figures 7.1 and 7.2) may be a primary drivers to alter land use.
Change in farm size
Between 1982 and 1997, the total number of agricultural holdings in Australia decreased from around 178,000 to 145,000. The greatest reductions were in smaller holdings of less than 1,000 ha, and especially <100 ha (Figure 7.3). As a consequence, the size of farm holdings in some agricultural sectors increased in some regions. For instance during these years, the number of sheep and beef cattle farms with areas between 100 and 5,000 ha increased, as did grain cropping farms having areas between 1,000 and 25,000 ha.
Change in farming intensification
An index was developed to identify and summarise any changes in farming intensification that occurred between 1983/4 and 1996/97*. The index compared changes between groups of land use as a proportion of the total agricultural area. Groupings were based on resource requirements and extent of changes to the natural environment - as developed in the Australian Land Use and Management Classification and used in the Audit's National Land Use map (see Figure 1.2 Setting the scene section).
Intensity was based upon the average cost of production for 1991 to 1994 taken from the Australian Bureau of Statistics Farm Financial Survey. Intensity should not be interpreted as a measure of negative impacts on the natural resource base.
The greatest range of change in land use intensity occurred in a broad crescent that curves around inside the east coast, around the south coast to the southern part of the west coast of Australia and includes Tasmania (Table 7.1, Figure 7.4), reflecting change that occurred between cropping and pasture. Areas further inland appear to have changed less, possibly because of fewer viable land use options.
The areas of greatest change:
- surround large population centres;
- often occur near irrigation areas; and
- most likely reflect changes in semi-intensive cropping and horticulture.
Some pockets also occur within these regions where little change in land use intensity appears to have occurred (e.g. in south-east Queensland extending into the northern tablelands of New South Wales, in eastern Victoria, the Eyre Peninsula of South Australia and eastern Western Australia).
Table 7.1 Grouping of land uses into categories and the intensity factor applied to derive the agricultural Land Use Intensity Index (see Figure 7.4).
| Land use category | Major components | Intensity factor |
|---|---|---|
| Extensive grazing | Native pasture, residual | 0.5 |
| Sown pasture | Lucerne, grasses, legumes | 7.5 |
| Broadacre crop | Cereals, oilseeds, pulses | 7.5 |
| Semi-intensive crop | Cotton, rice, sugar cane, potatoes | 125 |
| Horticulture | Fruit, nuts, vegetables | 275 |
* Data from the 1995 agricultural census was omitted from calculations because a reduced range of items was collected in the Agricultural Census in this year.
Change in type of land use
Pasture
Native and naturalised pastures and cleared scrub were steadily replaced with sown pasture in all States from 1960 until about 1970. In Queensland, this changing land use continued until 1994 (Figure 7.5). The sharp decline across Australia in 1996 and following years reflect the change in definition of the items collected by Australian Bureau of Statistics, not necessarily land use changes.
Intensive and semi- intensive commodities
- Horticulture (all vegetables except potatoes, fruit, nuts, vines, nurseries and turf) increased in all States. Collectively, these total areas are small and are concentrated around cities and within irrigation districts.
- Cotton in the growing areas between Moree Plains and Warren, in the Darling Downs and in the Central Highlands of Queensland, increased in area by at least 5%.
- Sugar cane along the tropical/subtropical eastern coast increased sometimes by more than 10%. However, within these regions small areas near Innisfail, Ayr-Home Hill and Bundaberg declined due to competition for land from horticulture (e.g. bananas, paw paw, melons, mangoes) and hobby farm development.
- Rice in the Murrumbidgee Irrigation Area (New South Wales) increased by about 5%.
- Potato increased in many regions by about 5%, with 10% increases occurring near Devonport in Tasmania, in southern Victoria and south-east Queensland.
ENTERPRISE DIVERSIFICATION 
Diversification is an important mechanism for managing risks in production, markets and income streams. It can also introduce biological resilience and productivity improvements within crop rotations and grazing systems.
A number of agricultural indices were assessed to evaluate temporal and spatial changes in the levels of farm diversification:
- Shannon's Index of Diversity;
- examination of crop type as the ratio of non-legume crops to total crop types;
- calculating the ratio of enterprise diversity and land use in five enterprise categories.
The last was explored using detailed data collected in the Australian Agricultural and Grazing Industry Survey by the Australian Bureau of Agricultural and Resource Economics.
Ratio of non-legume crops to total crop types
The assessment examined crop type as the percentage ratio of non-legume crops (pulse and oilseed crops) to total crop types (Figure 7.6). This index showed the most diverse areas of winter cropping occur in:
- northern parts of the Western Australian wheat belt, reflecting intensive use of lupins in crop rotations;
- the lower South East region of South Australia and the Wimmera of Victoria where pulse crops and canola are now grown with cereals; and
- in the Central Highlands of Queensland, where sunflowers have increased considerably, but also where areas under winter cereal are not large.
Farm product diversity
The degree of farm product diversity was calculated as a diversity ratio using enterprise diversity and land use proportions of five enterprise categories. The index ranges from one to five depending on the number of on-farm enterprises. A value of one for a farm indicates a specialist farm (e.g. in the northern pastoral regions of the Northern Territory and Western Australia cattle production is typically the only broadacre activity undertaken); a higher diversity ratio value indicates farms with multiple or mixed enterprises. Mapping of broadacre crops as a proportion of total crop (Figure 7.6) shows:
- a moderately high product diversity for broadacre farms occurred in the cropping zone;
- higher farm product diversity areas occur in southern New South Wales, northern Victoria and southern Western Australia; and
- regions of highest farm product diversity within broadacre farms are consistently found in the traditional wheat-sheep belt of southern New South Wales and northern Victoria.
TRENDS IN AGRICULTURAL PRODUCTIVITY
Grain productivity
Trends in grain yields for 1982 to 1997 were calculated using the Stress Index model (Stephens 1997) that removes major effects of climate - important since two major droughts occurred during the study period. Trends were expressed as kilograms of grain per hectare per year.
Wheat showed the highest increasing trends in yield (Figure 7.7) when compared with other grains - barley (Figure 7.9), oats (Figure 7.10) and sorghum (Figure 7.11).
- The highest yield trends in wheat (Figure 7.7 ) occurred in the north-west and south-west cereal regions of Western Australia; south-eastern and north-eastern regions of New South Wales; more reliably yielding regions of South Australia; and the south-eastern edge of the Darling Downs in Queensland.
With the exception of the north-eastern regions of New South Wales, all of these regions had high crop diversification (Figure 7.6), and in all regions new, advanced crop production practices and rotations have been adopted widely (e.g. in Western Australia, the use of high-yielding, short -season wheat varieties; early sowing; use of zero/minimum tillage; use of lupins and other pulses in rotations; and the use of nitrogenous fertiliser have combined, in the absence of droughts, to provide strong yield improvements through higher-input farming systems; in north-eastern New South Wales crop agronomy now uses increased nitrogenous fertilisers; better weed control during fallowing; and the use of sorghum as a break crop for disease. - In South Australia, wheat yield trends were closely related to total seasonal rainfall: higher yield trends were observed in the more reliable rainfall regions (45 kg/ha/year) with only 30 kg/ha/year in the more arid cropping regions. More cropping options exist in the more reliable rainfall regions to control root diseases and increase supply of soil nitrogen.
- In the Wimmera region of Victoria, low yield trends in wheat were associated with high crop diversity (Figure 7.6). This has been partly attributed to the replacement of long fallows (for conserving soil moisture for the main wheat crop) with pulse and oilseed cash crops. This region also has negative phosphorus and nitrogen balance.
- Yield variability in wheat (Figure 7.8) was particularly high in Queensland regions with low yield trends following droughts in the early 1990s; the drier upper Eyre region (South Australia) and in central New South Wales. Low variations in wheat yields existed across Western Australia; the more reliable cropping regions of South Australia; and the slopes of southern New South Wales and north east Victoria.
- Trends in yield for barley (Figure 7.9) were similar to those for wheat, but generally lower due to lower nitrogenous fertilisers being applied to malting barley crops, that require low protein levels in the grain. When considered on a regional basis, some barley yields were higher than those for wheat (e.g. in southern regions of Victoria and Western Australia, where barley is better able to tolerate waterlogged or saline soils).
- Yield trends for oats were generally lower than for wheat or barley. Oats and other cereals (rye and triticale) do better in wetter, cooler environments, consequently yield trends are higher in southern Australia. The highest yielding regions were: south-west Western Australia, mid north and south-east regions of South Australia and south-east New South Wales. In these areas, farmers improved the management practices of oats and started applying more nitrogen as oats become more profitable.
- Sorghum is a summer crop and yields improved markedly in northern New South Wales, in conjunction with improved management of nitrogen (Figure 7.11). However, in Queensland, droughts in during the first half of the 1990s severely impacted on yields and the use of nitrogen fertiliser was less common.
Water use efficiency
Water use efficiency provides an index of how much water - from soil stores and rainfall - is used by the crops to produce grain. The unused remainder may run off, evaporate from the soil surface or drain beyond the depth of roots. Water use efficiency represents a possible unused resource for achieving higher productivity. Water use efficiency was calculated as the ratio of actual yield to potential yield (as estimated by the Stress Index model - Stephens 1997).
- The pattern for wheat (Figure 7.12) showed that areas receiving summer rainfall (i.e. northern New South Wales and Queensland) have low water use efficiencies (less than 50%). However, in many cases these areas have the option of growing summer crops to use rainfall more efficiently.
- Higher water use efficiencies (greater than 70%) occurred in the Riverina, on both sides of the Murray River, in the Wimmera, Yorke Peninsula and southern Eyre Peninsula, and in shires in the drier eastern part of the Western Australian wheatbelt.
- Many regions are still producing well below potential.
Livestock productivity
National and regional statistics on the key grazing productive measure, livestock production/hectare, are not recorded. Broad estimates of stocking rate per hectare for agricultural regions (determined as dry sheep equivalents) were prepared as a first approximation, from estimates of annual pasture productivity and averaged for the years 1983 to 1997 (Figure 7.13).
CONCLUDING COMMENTS
Australian agriculture, in the most general terms across all commodities, is best regarded as in a phase of consolidation. Key features include:
- contraction of agriculture away from marginal areas and consolidation of farm size and enterprises;
- incorporation of a mix of commodities on farm, seeking opportunities for more diverse and market responsive production;
- improvements in farming systems, integrating considerations of climate variability, soil type, soil fertility and water use efficiency;
- development of higher input-higher output systems, maximising gains from fertilisers, cultivation techniques, feedlots and irrigation;
- targeted and more integrated research, development and extension, delivering improved varieties, cultivation and breeding techniques within a farming systems context; and
- rationalisation of processing and marketing arrangements, moving away from localised cooperatives and single-desk selling arrangements to positioning commodities globally.
These shifts are all likely to continue and, fostered by a new generation of agriculture policies and partnerships, will deliver improvements in the profitability and productivity of Australian agriculture.
REFERENCES
Stephens D.J. 1997, Assessing and forecasting variability in wheat production in Western Australia, final report to Agriculture WA.
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