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  • Harriet Mella

    August 31, 2021 at 2:16 am

    The basic new idea of Ducerf is that the agricultural manipulation of soil will lead to conditions you see in environments that are e.g. naturally wet and (periodically) waterlogged or excessively fertilized (e.g. in spots where ruminants lay down to “ruminate” and poo allover).

    The other line is the quality of the clay/humic complex (which pretty surely relates also to the type of mineral profile attached to it).

    The idea in older literature neglects the change that the method imposes on the soil functioning and was thinking more of the mineral, moisture, nutrient availability and climatic profile. I think this is owed to the fact, that methods of the last century had “less impact” and were inducing slower changes – if you listen to the Johnson podcast you see evidence of how fast chemistry applied by drip irrigation is changing soil behaviour. Ducerf has added the redox dimension and quality of humic complex explicitely and the mineral profile implicitely by looking into vegetable/animal origin.

    So if a wild species invades your ground with moderate moisture that should be growing in wet/waterlogged spots you know that you have created conditions where the soil metabolism has tipped into low redox/soil acidity. Usually through compaction or the overconsumption of oxygen in relation to the ventilation capacity of the soil (quantity and structure of pore space).

    Persistent low redox/soil pH will liberate metals out of the SOM-adsorption. Then you see weeds that can cope and detoxify aluminum.

    If your soil makes species like ambrosia explode, you know that you have created a functional desert without functional humic material.

    If too much vegetable material accumulates that is not cycled in the system through the animal channel, i.e. that vegetable matter (and the corresponding mineral profile!) accumulates, you get the natural progression towards forest and species of the woods appear.

    My personal fun was to identify mediterranean species growing on soils that display a hidden sodicity/salinity aspect. So if onions, fennel, asparagus and also in general the brassicas thrive, you have likely a lot of ions in the bulk water and a dash of salinity.

    The main point to apply Ducerf correctly is abundance and explosion of a species. This is usually coupled to fitness, but not assessed in the system. I have seen some of these succession waves on my ground and I have seen e.g. Lambsquarters in the first years from 2m high degrading to 15cm and full of root aphids. The downside is that I have experienced the last year the first problems to reproduce, not to grow, brassicas and spinach. Interesting not the beets/mangold.

    I write this being distracted by my daughter, so I hope this is still sufficiently coherent and accurate 🙂

    Best H