August 15, 2000

AUSTRALIA WHEAT:
CURRENT RAINFALL PATTERN MAY REDUCE GRAIN YIELDS THIS SEASON

WHEAT REGION: Background Information RAINFALL GRAPHS: Cumulative Precipitation May 1 to August 15 WHEAT REGION WEATHER STATIONS: Map SATELLITE IMAGERY: NSW Agricultural Area | 2000-1997-1996 | Previous Reports:

Australia Wheat Region Review:
Rainfall total accumulation and distribution has remained below average for the growing season. Western Australia continues to be well below normal for the period from May 1 to August 1, as does most of the grain growing area of Queensland. South Australia, Victoria, and New South Wales are all slightly below average for total cumulative precipitation.

Rainfall Analysis: Eighty-four stations were selected from Australia's main wheat and grain regions providing coverage of all five major grain producing states. Cumulative precipitation data was aggregated for all stations to perform a year to year comparison. The cumulative rainfall for the wheat region this year is the lowest of the previous four years. The analysis revealed that 1997 had the most similar rainfall regime to the current season. The pattern of the 2000 rainfall accumulation by state is very similar to that of 1997 on a state by state basis, as well as nationwide. A comparison to the 30-year average was calculated for the eighty-four stations as well, with the years 1997 and 2000 falling noticeably below the 30-year normal. If the trend continues it will irreversibly reduce the yield potential of the Australia winter crops for the 2000/01 season. [Wheat Region Rainfall Analysis] [Wheat Region Weather Station Map]

New South Wales and Queensland: Queensland, in northeast Australia typically contributes the smaller share to Australia's total production. However, the state of Queensland also has the greatest variability in yields for the last ten years of data. Analysis of Queensland's cumulative precipitation data with start of season date set at of April 15, reveals significantly lower seasonal rainfall totals and the lowest in five seasons. Satellite data acquired along the border of Northern New South Wales and southern Queensland shows very similar vegetation health and vigor response as seen during the 1997/98 season. New South Wales is typically the second largest producer in Australia. Examination of Landsat satellite data from 1996 shows much more abundant and or healthier green vegetation as compared to the current season. The significantly higher rainfall amounts of 1996 would be the major contributing factors for the difference in yields. Yield data from the states confirms 1996 being a high yielding year in both Queensland and New South Wales. The 2000/01 season looks very similar to 1997/98 season and will likely produce similar yields. [Northern New South Wales Scene Comparison 2000-1997-1996]

Summary: Conditions have been drier than normal, with many areas experiencing the driest conditions in the previous four seasons. Western Australia had a difficult start at planting and rainfall has remained below normal. South Australia, Victoria, and New South Wales appear to have satisfactory crop conditions, while data from Queensland shows the significantly below-normal rainfall. Australia is expected to have overall production levels above those of the 1997/98 season. However, production may be adjusted downward if no improvement in the rainfall pattern materializes during the next two weeks.

For more information, contact Jim Crutchfield with the Production Estimates and Crop Assessment Division on (202) 690-0135 or by e-mail at crutchfieldj@fas.usda.gov.

Northern New South Wales Scene Comparison 2000-1997-1996
Northern New South Wales Scene Comparison 2000-1997-1996 | top of page
Four million acres of land are covered in this sub-image scene near the border of Queensland having major cotton and wheat production. The scenes were acqured during the first half of July in their respective years. The crop area can be distinguished by the notceable red color tones in this false color satellite image. Crops in this region reflect strongly in the near and mid-infrared wavelengths which are displayed as red on the computer screen. Therefore the 2000 season and 1997 appear quite similar in green up and extent of vegetation. However the crop mix appears to be different as seen by more red tones which may indicate more grains planted and less pulses in 2000 compared to 1997. It should be noted that the northern New South Wales and Queensland had very high yields in 1996.

Northern New South Wales
Northern New South Wales Full Scene | top of page

Australia Wheat Region Weather Stations
Australia Wheat Region Weather Stations | top of page

Rainfall Accumulation Since Planting
Rainfall Accumulation Since Planting (May 1 through August 15) | Stations used in Comparison | top of page

Wheat Region Background Information
Australia Wheat and Climate | top of page
Wheat is Australia’s most important crop having a seasonal gross value approaching three billion Australian dollars. Australian wheat is a major competitor of US wheat exports. Australian wheat is grown as a ‘winter’ crop (autumn-winter-spring) often in rotation with some form of pasture. Wheat production is concentrated on the mainland in a narrow crescent know as the wheat-belt. The eastern portion of the wheat-belt stretches in a curve, inland of the dividing range, from central Queensland through New South Wales, Victoria, and southern South Australia. The western portion of the wheat belt continues around the south west area of Western Australia. The acreage planted to wheat during recent season has averaged 11 million hectares producing 19 million tons. Much of the wheat growing region is in sub-humid and semi-arid zones. This region has large areas of red-brown and black soils that are less leached and more fertile. These support Australia's wheat industry. Interestingly, Australian soil generally does not show a consistent correlation with climate, mainly because of the persistence in certain regions of leached soils formed in ancient wetter climatic conditions. The remaining portion of the wheat belt is grown in the higher-rainfall areas. These soils are low fertility, often needing trace elements as well as phosphorus, nitrogen, and sulfur. Artificial fertilizers can allow these soils to support highly productive pastures which have potential for mixed farming. In general, the Australian wheat, and other major crops (with the exception of sugarcane) are grown between the two extreme climatic zones. The interior edge of the agricultural crescent is formed by the exceptionally dry and erratic preciptation pattern of the interior, and the geographical outer edge of the wheat-belt crescent is created by the excessive moisture of the coastal climate where disease problems such as rust begin occur at levels which make wheat less economically feasible to grow. Winter rains over this narrow belt can be highly variable though in most years provides the needed moisture levels for crop growth. Virtually all of Australia wheat is rainfed. Irrigation is applied to higher value crops such as cotton and rice.

For more information, contact Jim Crutchfield with the Production Estimates and Crop Assessment Division on (202) 690-0135 or by e-mail at crutchfieldj@fas.usda.gov.