Cover crop decision making process

Jun 26

By Kim Deans

Multi-species cover cropping is gaining popularity as more farmers embrace a regenerative path. The feelings that accompany standing amongst a field bursting with a diversity of plant and insect life, can powerfully elicit an immediate reaction straight to source multi-species seeds. It is common to see the decisions about where to buy seeds being the extent of the planning that gets done.

It can be very easy to fall into the mindset that cover cropping will be THE answer to all your problems. Those who quickly jump onboard the trend, may be left wondering what went wrong when the exercise becomes expensive in terms of finances, or they fail to see the promised crop or soil health outcomes.

Cover crops can be a powerful tool to regenerate soils, reboot water cycles and introduce diversity, however they are not always the answer for every situation. It is more than likely that your perfect cover crop does not exist with every season. It is wise to consider a crops benefits, the potential problems and whether cover cropping fits with your goals. Good intentions and taking action in planting multi-species cover crops does not necessarily guarantee a beneficial or regenerative outcome. In less than ideal circumstances, and with poor management, the practice can lead to degrading soil health rather than the sought after improvements.

Developing your strategy by working through a decision-making process that indicates if cover cropping is the best tool for your unique individual situation will determine your success rate.

1. Clarify your goals for cover cropping and the benefits you are seeking for your soil and landscape. Unless you address your most limiting constraints the benefits from cover crops will be less than optimal.

2. Consider your budget. Do your sums and work out a strategy that does not increase your financial risk. Cover crops can take a number of years to gradually improve soil health and pay for themselves through a return on the investment. Farmers who are most satisfied with the returns on investment in cover cropping take a holistic approach and make a number of changes versus just adding a cover crop. They account for the costs and benefits over a number of years and allow at least 3 to 5 years of average seasons for the investment to pay off through productivity gains and reduced costs. Returns may come quickly in certain situations however they usually build gradually as the soil improves and the farmer gains experience with how cover cropping works in their situation. SARE found that cover crops pay their way more quickly when there are specific problems such as; herbicide resistant weeds, the cover crop is grazed, soil compaction is an issue, fertiliser costs are high and soil water holding capacity is low. These figures are based on cropping enterprises and in grazing enterprises cover crops can quickly add extra costs which are not being incurred through grazing perennial pastures.

3. Assess the risks thoroughly in relation to your climate and soil type. In low rainfall areas with high evaporation rates it can be more profitable and effective to step back and allow nature to do the work. Stepping back to allow native grasses to re-establish can provide the benefits of cover crops with none of the costs and a lot less work. Consider how you can send the signal for what you want to grow through your grazing management and using biological stimulants. It may be useful to manage climate risk by using your rolling average rainfall figures to guide decision making. You can set a benchmark and trigger points for when there is a greater likelihood for cover crops to return financially and ecologically in a similar way as these are used to make grazing decisions using your knowledge of your landscape and climate. Avoiding bare ground is key, does spraying out an existing pasture take you in the opposite direction for your goals?

4. Timing: Consider how well cover cropping fits within existing farm programs and seasonal patterns such as pasture growth and rainfall. Are you able to take advantage of optimum timings in relation to cover cropping?

5. Decide how to utilize the cover crop. Plan ahead for how you will use the biomass produced by cover crops in your system to bring about the benefits you seek. Will it be grazed, harvested for seed or fodder, roller crimped to provide a mulch for the next crop or green manured and worked back into the soil? Plan for optimal grazing and to avoid grazing when the soil is too wet or at risk of damage. This planning will enable you to capitalise on the benefits a multi-species crop provides.

6. Species selection: Consider which crops are most suitable for your soil types, climate zone and bring the benefits you are looking for in your cover cropping program. Are there suitable species that are resistant to pests and diseases or that can keep ground covered and outcompete problem weeds? There are excellent resources, such as https://smartmix.greencoverseed.com/ or speak to your local seed supplier about the benefits or services different species provide.

7. Record and be adaptive. There can be a human tendency to throw the baby out with the bathwater when things don’t work. Complex systems mean no two seasons will be the same, and what works well, or struggles this year, does not guarantee the same result in future. Observe and record climactic conditions, seeding timing, grazing timing etc, to diagnose and improve decision making for the next season.

After you experience the joy of being amongst the diversity and buzz of life that often accompanies a multi-species crop, remember to consider the first five steps in this process before you head straight to the species selection decisions. Consider the growing conditions, soil mineral and biological states of those showcasing the success of cover crops. They may have totally different factors at play which enhance their success. Time spent clarifying goals, your budget, assessing risks, considering timing and how to utilise the cover crop biomass will ensure you are on the right track BEFORE you spend money on seed. Resist the urge to start perusing the seed catalogue until you are clear on how this tool best fits your situation.

Remember there are no silver bullets in regenerating landscapes; each tool, management decision, observation and action work together to create results.

Cover crop decision making process

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