Biochar as feed supplement

Opinion: Where is agriculture’s place in a low-carbon economy?

One important focus area for biochar in NZ is water quality butting up against intensive dairy. Maybe this could be addressed in the future with more research on riparian margin biochar applications for P & N management.

Urine patching is another issue that has a biochar solution but how to solve economic issues?

This article has some comment on biochar.

“Lincoln University Professor of Biogeochemistry Leo Condron has been studying soil chemistry for three decades. He believes there’s “incredible potential” to use land management to alter CO2 and nitrous oxide emissions in New Zealand. Some farm management techniques are now well-proven. Only use as much fertiliser as you need and target it well. Don’t send animals onto wet paddocks. Others seem to have potential. One of Condron’s studies involved applying biochar – charcoal made from waste biomass – to the kind of soil that’s found under dairy land. The result? A “massive” reduction, both in the lab and in the field, in nitrous oxide loss.Biochar doubles as a waste management and carbon sequestration tool as it stabilises and stores the carbon from the materials such as sawdust used to make it. The catch, Condron says, is that the best results in the test came from applying the equivalent of 30 tonnes of biochar per hectare, which isn’t currently practical.“At the end of the day, it has to be economic,” he says. “For individual farmers, it’s never going to be economic for a single farmer to make biochar. How do they make it?”

I think farmers or farmer co-op’s could make their own biochar in the future using farm biomass as & when available. So, if 30 T/ha of biochar is a reasonable number to solve the urine patch / nitrous oxide issue then how do we get there? Some thoughts…

  • add slowly, over a number of years
    • animal feed supplement
    • biogas catalyst for dairy shed wash water recycling
    • reseeding mix
    • fertilizer mix (organic, biological, NPK-C)
  • carbon farming payments
  • urea tax (N-tax)
  • P&N stripping at sewage treatment plants using biochar for water polishing (‘subsidized’ and pre-charged with P&N for return to the land),
On the first item only: Lets assume supplementary feeding of biochar to dairy cows proves to be good pathway. Ignoring the potential methane reduction and animal health benefits… How long would it take to get 30T/ha thru cows & into the pasture? NZ averages just under 3 cows /Ha so you could say how long to pass 10T biochar thru a cow. Herd homes and feed pads are becoming more common in NZ to reduce pasture impact but the biochar would still end up on/in the soil (some losses). Assuming the herd had access to supplementary feed (& biochar) for 250 D/yr…. If they were feed 100gms /day = 400yrs. Even a 1kg/day = 40yrs and this excludes losses in the system. So what sort of animal feed rates are being considered by the scientists? 
My thinking is that this pathway to the soil can only be complimentary to other systems.
But 30T/ha may be more than is needed in many scenarios, anyway?
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