The devil's in the detail: how farming systems fit by Nigel Wilhelm, Sustainable Farming Systems SARDI, Waite Precinct, Adelaide, South Australia.
GroundCover™ Issue: 34
There is never only one farming system that will produce an acceptable profit and protect the natural resource in any given situation. However, all successful farming systems will have these four attributes in common:
- a high frequency of phases that return large cash profits
- a low level of diseases and pests in all phases
- low weed burdens
- natural resources that are preserved or improved.
Factors for developing a 'good' farming system
- Of all the factors under the control of the manager, rotational choices will have the largest impact on profitability.
- A good rotation will realise its potential benefits only if most or all management practices are implemented in a timely and competent way.
- There is no 'quick fix' or magic recipe. It may take 5-10 years for a 'good' farming system to show benefits.
- Continuous cropping will return the highest profits in all environments but it is the most complicated to manage and has the highest penalties for mistakes — particularly difficult in low-rainfall environments.
- High-yielding, good-quality wheat is still the most reliable and profitable crop, so farming systems should be set up to give every wheat crop the best possible chance of performing well.
- Should wheat be grown after wheat? Only if you know it will perform well. This prediction cannot be made without detailed knowledge of weed, pest and disease burdens in the paddock.
- All current seeding techniques can produce vigorous, dense and even stands of crop. Thus, tillage decisions must be based on their impacts on weed and disease cycles, and on erosion and compaction risks, NOT on crop establishment. In the absence of weed and disease burdens, crops established with no-till will yield at least as well as conventional cultivation in nearly all situations.
- Full stubble retention must be the norm — stubble should be removed or burnt only as a last resort to achieve very deliberate purposes. Seedbed preparation is NOT an acceptable reason for removing stubble.
- Regular monitoring and recording of soil condition and fertility, disease burdens and weed seed banks are essential ingredients for successful implementation of a crop sequence.
- The outcome will be only as good as the quality of the implementation. For example, a delay in seeding wheat of only four days may cost 120 kg/ha of yield. In a seeding program of 500 hectares of wheat, the total cost of this delay alone could be $8,000 (or one-quarter of a modest family income).
- Fertilisers represent the single largest input cost into cereal cropping and thus are an obvious target for cost cutting. However, fertiliser rates should always be based on likely crop requirements, so decisions to arbitrarily reduce application rates should never happen.
- Deep soil N testing is currently the best tool we have for making informed N decisions.
- When in doubt, diversify. Weeds, pests and diseases work by exploiting weaknesses and patterns. Don't be predictable; seasons are never regular, nor should your farming system be.
- Integrating livestock and cropping on the same piece of ground is always a compromise for both components. Under current financial constraints, this compromise is often too unbalanced to work properly.
- If managers and the industry do not address natural resource protection issues, the community will, and that will take the decision making away from the people who manage the land.
- Access good advice, which probably means paying for it.
Contact: Dr Nigel Wilhelm 08 8303 9353 email firstname.lastname@example.org
Region North, South, West