What is Sustainable Agriculture’s Critical Role in Climate Change?

Graeme Sait’s latest video blog entry.







If you cannot see or play this video, please download the latest version of Adobe Flash Player. Click here.

5 Responses to “What is Sustainable Agriculture’s Critical Role in Climate Change?”

  1. emily Says:

    Ah always a pleasure hearing you talk :) ..you look very relaxed by the pool speaking refreshing words of wisdom! i like the new blog section – it’s a good reminder of various ideas and topics discussed during your course, thanks again.. em

  2. Andrew Radford Says:

    Tony Burke MP has stated that the reason for agriculture being excluded from the Carbon Pollution Reduction Scheme is “science of measurement is not there yet”. What are your thoughts?

    We can measure soil for levels of organic matter/humus.
    Why isn’t this adequate as a form of measurement to be included in the above scheme???

  3. Adam Sait Says:

    There is a problem with monitoring increases in organic matter levels to allow compensation to farmers via carbon credits.The problem relates to the type of carbon measured. The current soil test for organic matter actually measures a combination of three things including raw organic matter, active organic matter and stable organic matter. It does not differentiate between these three and that is essential because it is only stable organic matter that has any shel flife i.e retention time in the soil. Raw organic matter is undecomposed material from crop residues etc. Active organic matter is largely created by bacteria and may last for just a few months in the soil. This short term material is dominated by the very small fulvic acid molecule that is easily leached. Stable organic matter is largely produced by fungi and this involves the formation of clay/humus bonds that are much more stable. . This material is dominated by humic acids and it can last for 35 years in the soil. This is obviously what we should be paying farmers to produce but the current test doesn’t single out the good guy. One thing we do know is that the cellulose digesting fungi responsible for creating stable humus have been decimated by conventional farming practices. They can be reintroduced with inexpensive innoculums but then they need to be supported and this will involve a biological approach. There is simply no other way.

    - Graeme

  4. Conrad Says:

    I was reading that the ocean is responsible for fixing most of the carbon, approx. 90%, curious what your thoughts are on this?

    Regards,
    Conrad

  5. Graeme Sait Says:

    Hi Conrad,

    You are correct in that huge amounts of CO2 are stored in carbon life forms in the ocean (800 gigatonnes) but the ongoing fixation of carbon from the atmosphere is offset by the respiration of these creatures. Micro algae are the big players as they produce (effectively fix) huge amounts of carbon through photosynthesis. However, recent research has revealed that respiration from ocean creatures in the North Atlantic is actually responsible for the production of more CO2 than is sequestered. These oceans are actually a carbon source rather that a carbon sink.

    The importance of phytoplankton as the basis of ocean food webs cannot be over-emphasised and herein lies a looming disaster. The oceans have been absorbing over 30% of the anthropogenic (manmade) CO2 that we have produced during the cheap oil-fueled, post-war party and this has resulted in the production of carbonic acid that is acidifying our oceans. This ongoing acidification will have a serious impact upon calcium-based life forms, including algae and krill.

    This is based upon the fact that calcite and aragonite (forms of calcium carbonate) are stable within a very precise pH range, but as the ocean water becomes more acidic, the concentration of carbonate ions falls. Not only is it more difficult for marine creatures to form calcium carbonate but calcium carbonate structures begin to dissolve. Coral reefs are based upon aragonite and phytoplankton form their shells from calcite. The loss of these creatures means the potential loss of the huge range of creatures dependent upon them (including man). This is an issue that is more urgent than any other in relation to the massive challenge confronting the planet at present.

Leave a Reply