Q2. What are the future works in "Assessing costs of soil carbon sequestration by crop-livestock farmers in western australia" ?
Further work is needed to compare the emissions associated with agricultural production against soil carbon sequestration potential. Further work is required to assess the impacts of possible adverse climate change on SOC and the changes in farm profitability under such conditions. While uncertainties in costs and prices can be challenging for farmers, additional factors that may impose a risk on the farmer who has entered into a carbon contract include: climate change or natural disasters that could reduce or re-release SOC in the atmosphere ; possible changes of the policy program sometime in the future ; and future technology developments that could either mitigate climate change effects more cost-efficiently than SOC sequestration or that could raise the opportunity cost to farmers of participating in SOC enhancement. Nutrient application n the form of fertiliser would involve additional cost that would further reduce the economic attractiveness of the sequestration activities.
Q3. What are some practices that farmers can adopt to reduce SOC losses from the soil?
Practices that farmers can adopt to reduce SOC losses from the soil, and/or potentially reabsorb (sequester) carbon in their soil include:Conservation tillage;Increased retention of crop residues or “stubble”;Regrowth of native vegetation;Reduced frequency of fallowing;Conversion from annual to perennial crops or pasture;Grazing and livestock management: for example, intensive rotational grazing;Sowing improved grass species that produce more biomass.
Q4. What is the maximum profit for a high crop-price scenario?
In a high crop-price scenario, a larger proportion of farmland will be allocated to growing crops, and the maximum attainable profit predicted by MIDAS, may be as high as $166 per hectare per year.
Q5. How much of the global greenhouse gas emissions are from agriculture?
It has been estimated that agriculture accounts for about 14 per cent of anthropogenic greenhouse gas emissions worldwide (FAO, 2001).
Q6. How many farmers remove their residues through burning and grazing?
According to Llewellyn and D’Emden (2010), around 22 per cent of farmers remove (a proportion of) their cereal residues through burning and grazing.
Q7. How many growers in the region have adopted no-till or minimum tillage techniques?
Nearly90% of growers in the region have adopted some form of no-till or minimum tillage sowing techniques (Llewellyn and D’Emden, 2010).
Q8. What are some of the incentives that farmers can adopt to reduce SOC losses from their soil?
Some SOC sequestration management may lower farm profits (e.g. when changing from a high-value annual crop to a lowervalue grazed perennial), in which case incentive schemes may be needed to compensate farmers.
Q9. Why does the model not quantify crop productivity?
Because of the limited biophysical evidence and biochemical uncertainties about the relationships between soil organic matter and crop production (Baldock and Nelson 2000), the model does not quantify possible changes in crop productivity due to increased SOC levels i.e. the model does not ascribe any production benefits due to the level of SOC per se.
Q10. What is the average SOC-sequestration potential for Australian soils?
The estimated SOC-sequestration potential for Australian soils is, on average, lower than potential sequestration of northern hemisphere soils due to a less favourable climate and edaphic constraints (Sanderman et al., 2010).
Q11. Why do the authors need to change to conservation tillage?
Because of additionality requirements in the CFI (see Section 6), analyses of changing to conservation tillage therefore have limited relevance for Australian broad-acre mixed farm systems.
Q12. How long is the potential reduction in farm profit?
Commodity prices are likely to varyconsiderably over a 100-year period, which means that the potential reduction in farm profit is highly uncertain.
Q13. Why are there low participation rates in the Australian soils?
These low participation rates were not a result of carbon prices per se, but rather due to the large proportion of farmers that has already adopted reduced or no-tillage practices in Australia, even without carbon incentives (Kearns and Umbers, 2010).