Vegetable Production
in the Lockyer and Fassifern Valleys, eastern Darling Downs and Toowoomba range.

Stephen Harper, Peter Deuter and Dan Galligan, Department of Primary Industries and Fisheries.

Introduction

In south eastern Queensland, the Lockyer and Fassifern valleys, the eastern Darling Downs and the Toowoomba range are major production areas for a range of vegetable crops. These include, potatoes, brassicas (broccoli, cabbage, cauliflower and chinese cabbage), onions, carrots, lettuce, sweet corn and celery. Additionally, more than 60% of Queensland's production of processing crops including sweet corn, beans, peas, beetroot, and carrots, come from these areas (see table 1). A wide range of other vegetable crops are also grown on a much smaller scale.

Table 1: Production estimates - Lockyer Valley (1997)

CROP	AREA	Prod.	VALUE	% of Qld
	(ha)	(tonnes)	($M)	Prod.
Fresh market vegetables
BEANS	300	1500	0.36	30
BROCCOLI	600	3444	5.71	85
CABBAGE	80	2352	1.68	60
CAPSICUM	80	1344	2.22	5
CARROTS	180	3600	1.26	100
CAULIFLOWER	150	4410	2.21	60
CELERY	150	7920	3.89	80
CHINESE CABBAGE	40	2400	0.89	60
GARLIC	6	48	0.02	80
LETTUCE	500	11250	7.38	80
ONION	650	26000	16.12	90
POTATO	2300	48300	25.84	75
PUMPKIN	1800	36000	7.56	45
SWEET CORN	300	2700	2.91	15
TOMATO	300	5700	6.16	10
SWEET POTATO	4	100	0.06	30
WATERMELON	250	3750	0.83	15
TOTALS	7690	160818	85.1
Processed vegetables
BEANS	80	800	0.27	70
CARROTS	28	532	0.11	100
BEETROOT	630	2720	3.47	100
PEAS	300	1500	0.45	95
SWEET CORN	650	9100	1.27	70
TOTALS	1688	14652	5.57

Soils and topography

The major soil types used for vegetable production vary from district to district.

Alluvial clay loams

Black alluvial clays and clay loams are the most productive soils in the Lockyer and Fassifern valleys and consist predominantly of montmorillonite clay. In their native state they are highly fertile and of neutral to slightly alkaline pH. Under continual cropping, responses to additional fertiliser (particularly nitrogen and potassium) can be expected. The soils associated with the upper catchment tributaries and the levee banks of the Lockyer creek are generally well drained and of loamy texture, whilst other alluvial soils of the region are generally heavier and not as well drained. However, almost all of the black alluvial soils in the region are suitable for irrigation. In the Fassifern and Lockyer Valleys, production has also developed on small patches of Brigalow scrub soils (grey clays) and extended into some other marginal soils. Production areas in the Lockyer and Fassifern valleys are on flat, slightly sloping and undulating soils along the major streams and their tributaries. Some of the areas are subject to sporadic flooding depending on the proximity to the watercourse and the height of the floodwater.

Krasnozems

The krasnozems of the Toowoomba range are generally deep and well-drained red clay loams of predominantly kaolinite clay, and oxides and hydroxides of iron and aluminium. In their native state they are highly fertile, both chemically and structurally. However under continual cropping, this fertility is rapidly run down and hence they are generally of lower nutritional fertility than the black alluvial clays. Krasnozems are acidic and generally require lime and fertiliser for intensive vegetable production. After a few years of intensive farming the addition of organic matter is important in improving nutrient availability (particularly phosphorus) and buffering against increased acidity (low pH). Most of the areas where this soil type predominates have been taken out of production by urban encroachment.

The red soil areas on the Toowoomba range are at the highest elevation of the four areas and so have milder summers than the Lockyer and Fassifern valleys but also milder winters than the eastern Darling Downs. Importantly, some areas where these soils predominate are frost free, particularly on the eastern slopes of the range.

Eastern Darling Downs soils

The eastern Darling Downs contains a wide variety of soil types with different characteristics. For example, the Purrawannda dark medium clays are fertile and well drained. Grey to brown alluvial cracking clays also exist in large areas of the eastern Darling Downs and where irrigation water is available these soils have been cropped intensively to vegetables. These clays are generally fertile and alkaline but vegetables grown on them do respond to fertiliser application.

The areas used for vegetable growing are mostly on slightly sloping land previously used for grain crops. Small areas of lettuce, celery and broccoli are produced on higher land with a north easterly aspect. These areas are well protected from cold west and south west winds, so are generally warmer in the winter and escape the sever frosts which can fall on the more exposed selections.

Soil problems

In all of these districts there are extensive areas of soil which either have particular management problems restricting production or are totally unsuitable for vegetable production.

Even the most fertile alluvial soils of the Lockyer Valley can present management problems. Surface crusting after rain or irrigation hampers seed germination and restricts aeration. Heavy clay soils restrict access when wet and stay wet for extended periods. In the Fassifern Valley some of the heavy clay soils are poorly drained and cultivated hillsides can be infertile and prone to erosion. The areas of shallow red clay soils of the Toowoomba range have limited soil depth, are prone to erosion and compaction, and often require artificial drainage.

The wide range of soil types on the eastern Darling Downs each have their own particular management problems. For example, heavy self-mulching clays present germination problems. Successful farmers accurately match soil type, irrigation method and crop choice.

Large areas of ridge and scrub soils are generally of very low fertility, frequently present drainage problems and lack available irrigation water. The DPI&F publication Buying the Farm for Horticulture offers practical step-by-step instructions on assessing soils for their suitability for horticultural production.

Climate

Climatic variations exist across the four districts but in general the pattern is as described below in table 2.

Table 2. Climatic data for the Lockyer and Fassifern valleys, eastern Darling Downs and Toowoomba range.

Centre	Average annual rainfall (mm)	January mean maximum (° C)	July mean minimum (° C)
Ipswich Gatton Boonah Toowoomba Crows Nest Ravensbourne Pittsworth Dalby	876 912 866 955 861 1160 696 673	32.1 31.3 NA 26.9 NA NA 29.8 31.6	6.9 5.5 NA 4.2 NA NA 4.8 3.9

Rainfall

Rainfall is distributed unevenly throughout the year, with up to 60% falling during the summer months (December to March). The spring months of August and September are often the driest. The total rainfall varies from 1000mm in the eastern districts to 650mm in western districts, in general decreasing inland except for higher rainfall caused by the Great Dividing Range at Toowoomba.

Temperature

Temperature extremes occur from severe winter frosts (-10° C) to summer heatwave conditions (>40° C), in various locations across the region.

Summer maximum temperatures are modified by coastal influences in eastern districts and by the altitude of the Great Dividing Range at Toowoomba. High summer temperatures with occasional heatwaves occur on the eastern Darling Downs. The maximum summer temperatures experienced in the lowland areas of the Lockyer and Fassifern valleys are generally in the mid to high thirties.

Winter minimum temperatures vary from near frosting to severe frosting (-10° C) on the eastern Darling Downs. No areas are completely frost free, although some areas experience no frosts in some years. The major vegetable growing areas of the Lockyer and Fassifern valleys experience on average from one to three light frosts (-1° C) in most years. Areas of the eastern Darling Downs experience 20 to 30 frosts, some of which are severe.

Market timing: domestic markets

In recent years the method of vegetable supply to the domestic market has changed. Large volumes of vegetables produced in south eastern Queensland are still destined for the Brisbane, Sydney and Melbourne wholesale markets, with some going to Adelaide and Perth. However, more and more produce is now being supplied under contract, directly to chain stores and large supermarkets. In many instances the market is now demanding the adoption of Quality Assurance systems that guarantee consistent supply of market quality product. For some commodities a contracted grower supplies as an approved supplier to a Quality Assured packing shed for direct supply to a supermarket outlet.

South east Queensland is able to supply a wide variety of vegetables to appropriate markets throughout the year. This ability is highlighted by the production timing chart for the Lockyer Valley (Figure 1). The highest returns are offered when market supply is possible at times when other production areas can not satisfy the demand.

Figure 1: Supply capability chart for the Lockyer Valley

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Beans (proc)

Beans (fresh)

Beetroot (proc)

Broccoli

Cabbage

Capsicum

Carrots (proc)

Carrots (fresh)

Cauliflower

Celery

Chinese Cabbage

Garlic

Lettuce

Onion

Peas (proc)

Potato

Pumpkin Jarrahdale

Pumpkin Jap

Sweet Corn (proc)

Sweet Corn (fresh)

Tomato

Sweet Potato

Watermelon

Market timing: Export markets

Australian producers face competition on overseas markets from countries such as South Africa, USA, South East Asia and Brazil. Markets need to be investigated and developed in a thoroughly professional manner.

The establishment of large volume, long term export markets is considered to be the only option for the long term stability of the Australian vegetable industry.

The major items of importance in export marketing are:-

• Availability

- of products
- of markets, particularly making use of seasonal advantages.

• Reliability

- regularity of supply
- consistency of supply.

• Performance

- quality of product
- packaging
- meeting deadlines
- suitable pricing policies.

Successful exporters are those who have made the commitment to supply the export market regularly and reliably with a product which meets the export market specification. Export markets should not be viewed as dumping grounds for surplus production and supply commitments should be honoured regardless of domestic prices.

The south eastern Queensland region currently exports a number of crops including broccoli, onions, Chinese cabbage, sweet corn and celery.

Success depends on supplying markets at periods when growing is most profitable (eg. winter brassica production in the Lockyer rather than summer production). An example of this is the production of Chinese cabbage in the Lockyer Valley from June to October to supply the Singapore and Hong Kong markets.

Production limitations

Markets

The key to long term market profitability is being able to produce a highly marketable product and develop a successful marketing strategy.

With modern post-harvest handling and transportation, no major market in Australia is beyond the grower's reach. Proximity to the Brisbane wholesale markets no longer provides the advantage it did in past years. Growers from other vegetable growing areas from north Queensland to Victoria to Western Australia compete directly with Lockyer Valley growers as there is little difference in freight and handling costs.

Irrigation water supply

The major source of irrigation water throughout the area is groundwater from alluvial aquifers. Other water sources include direct pumping from streams, off stream storages and on-farm catchment dams. Most crops need at least 4 ML/ha of water. The four production areas at times have low quantities of irrigation water. However, the water quality is generally suitable for vegetable production and use of this water on local soils presents no major problems.

Groundwater in the Lockyer Valley comes from a series of localised alluvial aquifers which vary in their quality and quantity of supply. The Department of Natural Resources and Mines (NR&M) has determined that average annual use exceeds safe annual recharge. This means water shortages are likely to be a recurring problem. Some areas in the Valley have been declared and will be controlled by NR&M with assistance from local Water Advisory Boards. Saline waters in the area have been used effectively with careful crop selection and irrigation practices. Poor quality water has the potential to reduce crop growth and downgrade soil structure.

The Fassifern Valley is similar to the Lockyer in having a series of aquifers supplying water. Where water is available it is generally of reasonable quality.

Temperature

Extremes of temperature are the major limitations to vegetable production in these four districts. High temperatures during the summer, combined with normal summer rainfall, limit summer production of many vegetable crops. Production during late summer and autumn is less likely to be adversely affected by these weather conditions.

The Toowoomba range has a milder summer because of its altitude, allowing the production of crops such as lettuce and celery over this period.

Occasional heatwaves on the eastern Darling Downs preclude summer production of most vegetables except in some of the highland areas on the eastern extremities of the Downs.

Low temperatures during the winter prevent frost sensitive vegetable crops being produced in most parts of the four regions, except in very small areas which are well protected and have an extremely low risk of frost. The production season for most cold or frost sensitive crops ends with the onset of cold weather or frosts.

Extremely low temperatures on the eastern Darling Downs can limit growth and quality of some of the more cold tolerant vegetable crops. Mid-winter production in these areas is often hazardous for this reason.

Milder winter minimum temperatures in the Lockyer and Fassifern valleys enable high quality cold tolerant crops to be produced in most years.

Seedling production

Many intensive vegetables are established in the field using containerised seedlings. Brassicas, tomatoes, lettuce and celery are mainly established this way. Some broccoli and lettuce are direct seeded using precision planters.

Seedlings are usually produced by specialist contract seedling growers. Some growers, particularly those with extensive production units, are growing all or a proportion of their own seedling requirements. Vegetable seedling production is a specialised business. A high level of expertise and experience is required to produce the high quality seedlings which are needed in intensive horticulture.

Organic farming

Many vegetable consumers are interested in products free of residues of synthetic chemicals, particularly pesticides. Organic (biological, holistic, ecological or natural) farming is one method of providing this type of product.

Some fruit, vegetable and grain farmers in the region are using organic farming practices. A very high pest and disease pressure is normally encountered in an intensive vegetable production district. However, as more biological pesticides become available to the vegetable industry, the pest management problems associated with organic farming will become more manageable.

Hydroponics

Some vegetable growers in the region have established specialised market outlets for certain hydroponically (soilless) grown produce. However, many of the advantages often attributed to commercial hydroponic vegetable production do not apply in this region, which has the ideal natural environment for conventional production methods.

Hydroponic vegetable production normally demands a higher level of production technology than conventional cropping methods. A knowledge of how to grow a particular crop conventionally is a tremendous advantage to successful hydroponic culture. Establishment and running costs are higher, although a well designed system can save on labour.

Light and temperature control are critical if the hydroponic system is contained within a greenhouse. But few vegetable crops are naturally adapted to greenhouse cropping in the region. Hydroponic lettuce, for example, can be grown successfully in the open. The only vegetables so far showing potential for successful commercial hydroponic production in this region are lettuce (in the open) and cucumbers (within a greenhouse).

Conventional control measures, especially hygiene, are required to combat the same pest and disease problems that affect field-grown crops. However, some natural predators can be used more effectively in an insect-proofed greenhouse than in the open.

Anyone interested in hydroponic culture is strongly urged to attend a TAFE or similar course on hydroponics.

Future prospects

The commercial production of vegetables on farms in this region will continue into the future. Cropping types and patterns will change in response to changing markets, economic returns and management of resources, in particular water. There is little potential to expand production of vegetables for domestic markets. These markets are already well supplied for most of the year and increased production over and above market demand very quickly leads to reduced prices (see further reading).

Production aimed at meeting specific market demands will generally be profitable in the long term. Lucrative markets are very small and exist for very short periods of time each year.

An export market for some vegetables exists and the volume which could be marketed is many times larger than the Australian domestic market demands. The decision to produce for export must be taken seriously, carefully and purposefully. Any major expansion of vegetable production in the region would have to be aimed at this export market. Much greater vegetable production could potentially be achieved in the south east Queensland region, but only for supply to an export market.

Further information

Carr, A. (1986). Buying the farm for horticulture: site it right. Queensland Department of Primary Industries, Information Series QI86016.

DPI&F Notes in the Producing Vegetables for a Market series include:

1. Successful horticultural enterprises.
2. The production environment.
3. Matching crop requirements with the production environment.
4. Sensible use of irrigation resources.
5. Temperature requirements and limitations for a range of vegetable crops.

DPI&F, Gatton Research Station Ph (07) 54 66 22 22.

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Information contained in this publication is provided as general advice only. For application to specific circumstances, professional advice should be sought. The Department of Primary Industries and Fisheries, Queensland has taken all reasonable steps to ensure the information in this publication is accurate at the time of publication. Readers should ensure that they make appropriate inquiries to determine whether new information is available on the particular subject matter.

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Last updated April 1999