| Why is it important to me as a farmer?
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- Waterlogging is a major limitation to crop production in the region
- Paddock selection for cropping is critical and best management practice needs to be adhered to
- Raised bed cropping is an established method to overcome waterlogging and increase crop yields in high rainfall cropping environments
- Raised beds promote controlled traffic and minimum tillage practices that encourage improved soil structure and soil health
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- They are not applicable to all regions due to soil type constraints or slopes
- Where raised beds are not possible or feasible, controlled traffic techniques without beds should be considered
- Dairy farmers may find favourable economics in purchasing grains rather than taking pasture out of action to grow a crop during wetter years
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| What issues do you need to consider with cropping in this region?
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1. Crop production in high-rainfall zones
- The high rainfall zone (HRZ) (>550mm annual rainfall) is quite different from traditional cropping areas in the rest of Australia. It has a much longer growing season and this provides a lot more options for growers
- Croppers in the HRZ are able to sow in autumn or in spring and they have the option of grazing crops, so this provides a lot more complexity for making management decisions
- Improved crop yield experienced by farmers using this method has primarily been
attributed to the alleviation of waterlogging
- When considering cropping, there are several key steps that require consideration:
- Paddock selection - select well drained areas or consider raised beds
- Use of correct crop sequences � where possible, begin the cropping phase with a grass free period of one year and avoid planting more than two cereals in succession
- Maintain soil structure by using minimum tillage or direct drilling
- Control weeds
- Monitor the progress of your crop regularly for pests, diseases and nutrient problems
Paddock selection should aim to identify those paddocks which have the best potential to produce high yielding crops with the minimum cost. Factors which should be considered when selecting areas to crop are:
- Waterlogging � has been a major limitation to cropping in the region, so select paddocks that are less prone to waterlogging in winter. Alternatively, consider the use of raised beds.(see below)
- Weeds � avoid areas with problem weeds such as herbicide resistant ryegrass, sorrel, rushes, radish and beny grass as these will require extra cost and effort to control. Paddocks should be spray-topped or cut for hay in the year prior to reduce seed set
- Roughness � paddocks which are uneven and require levelling before cropping incur an additional expense
- Soil structure and nutrient status � select paddocks which have good soil structure and fertiliser histories. Undertake soil testing to identify nutrient status
- Paddock selection and choice of crops for that paddock will be closely influenced by soil type
Raised bed cropping
- Raised bed cropping, developed by Southern Farming Systems (SFS) and, Department of Enivironment and Primary Industries (DEPI) and agribusiness, is an established method of overcoming waterlogging and improving soil structure
- Raised beds have allowed large scale, productive cropping systems to be adopted in the HRZ. During the 2005-growing season almost 50,000 hectares of raised beds were cropped in south western Victoria
- The system uses controlled traffic, with vehicle wheels only travelling along the furrows between the beds
- Improved crop yield experienced by farmers using this method have primarily been attributed to the alleviation of waterlogging, but many farmers are also experiencing average to above average yields even in drier seasons
- Improved soil structure is a major contributory factor to this improved crop performance
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Issues
- Raised beds are not suitable for all situations. If raised beds are being considered, farmers should observe the best management practices (BMPs) to make the economic gains and minimise their effect on the environment
- These BMPs include:
- Careful planning is essential when starting a raised bed controlled traffic cropping system. The first critical step is to develop a whole farm plan. This gives a comprehensive overview of the development and ensures all aspects of the project are considered and planned. An accurate 10cm contour survey is essential for any raised bed development over 10ha
- Bed arrangement � raised beds should be aligned according to soil type and slope to avoid soil erosion. Raised beds are not recommended for slopes greater than 1.5 per cent
- Length of runs � the length of the beds influences the amount of water flowing down furrows. On an average slope of one per cent, the bed length should not exceed 400 metres
- Sowing crop in furrows � crop should be sown in furrows to prevent soil and nutrient movement, and also in the collector drains and headlands at the end of the beds to filter water running out of the furrows
- The use of minimum tillage, with press wheels and controlled traffic are essential components of a raised bed cropping system as they both encourage improved soil structure and soil health
- Headland and collector drain management � design systems to reduce potential erosion and allow increased traffic access in wet periods
- Permanent grassed waterways are essential for carrying water from upslope areas through or around a bedded paddock. Grassed waterways should have a slope of 1.5% or less. Communicate with neighbours and check local government regulations, as drainage water may affect neighbouring properties and local waterways
- Livestock management on beds needs to be carefully managed as animals can cause damage to beds in wet periods and sheep can become stuck in the drainage furrows
- Consideration should also be made for access tracks for fire management, water harvesting and storage and nutrient management
Figure 2 - An example of paddock water management for a raised bed system � a well designed headland and/or collector drain can make crop and water management much easier. � Source: DEPI Victoria
[View larger image]
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Figure 1 - Raised bed cropping. - Photo: DEPI, Victoria
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2. Dairy production and cropping for feed
- Normally there is a focus on filling feed deficits in dry seasonal conditions
- However in a wet year followed with a reliable spring harvest, there is likely to be less pressure to grow crops to fill feed gaps
- This means that grain may be purchased at a more reasonable price and would reduce the need for taking pasture out of action to grow a crop
- Things to consider:
- When costing a home-grown crop, include all the costs such as the pasture foregone, wastage, risk of failed crop/low yield, feed-out costs, conservation, transport, etc
- Pasture resowing costs
- Benefit from extra yield from the improved pasture
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Other related questions in the Brown Book
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Brown Book content has been based on published information listed in the Resources and References sections below
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- Ameliorating hostile subsoils in south-west Victoria. September 2005 � Grains Research
and Development Corporation.
- Soil Structure Differences Under Raised Beds. Hi-Grain Update, September 2004 �
Grains Research and Development Corporation.
- Raised Bed Headland,. Hi-Grain Update, October 2003 � Grains Research and
Development Corporation.
- Best Practice for Raised Bed Controlled Traffic Farming. Hi-Grain Update, March 2005 �
Grains Research and Development Corporation.
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- Raised bed resurgence tipped for HRZ. Grains Research and Development Corporation.
- High Rainfall Zone Cropping. Department of Primary Industries Victoria.
- Do the maths on cropping this season. Department of Primary Industries Victoria.
- Bluett, C. and Wightman, B. (1996) Cropping in South-West Victoria. Department of Primary Industries, Victoria.
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