Benedikt HaugMay 19, 2025
1/9 I have been visiting my colleague and former PhD supervisor Pierre Hohmann (@plant_holobiont) and Joan Romanyà from the Agroecosystems group of University of Barcelona last week – some impressions…
Show threadBenedikt HaugMay 19, 2025
2/9 Pierre is an absolute specialist when it comes to #PlantMicrobiome interaction. He actually doesn’t talk so much about an isolated #Microbiome, but rather of a combination of the plant and its microbiome:
Plant + Microbiome = #Holobiont.
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3/9 The group does a lot of research in #conservationagricultre and #carbonfarming. You know, not the murky shady #CarbonCaptureAndStorage thing, but for soil improvement. They have developed a system that they call "CarBoniato". They use prunings of the city (Barcelona), woodchips, and apply them on a large scale on fields and when I say in large quantities, I mean 15 kg m-1 or 150 t ha-1!
The soil-scientist in you might say: this is madness. The C/N ratio will skyrocket. No plant available N for the near future anymore!
May 19, 2025 at 1:03pmWeb
Show threadBenedikt HaugMay 19, 2025
4/9 This is true but not only part of the story. What they found out together with their farmers network is, that sweet potato (Boniato) works very well in the first year, and there's no yield loss with this crop (This is the Boniato part of CarBoniato). Afterwards, a low-N-demanding crop, such as faba-bean is being grown. After roughly a year, the woodchips have been digested by the soil life to a large degree and C/N is significantly lower already while the N in the wood (in 150 tons, there's about 1000 kg of N!) is being converted to stable forms that are accessible in the soil, contributing to the long term #fertility of the soils.
Show threadBenedikt HaugMay 19, 2025
5/9 The prunings of the city are otherwise being burnt in a facility and the city actually otherwise pays to get rid of them!
Show threadBenedikt HaugMay 19, 2025
6/9 I have checked the soils on one of the farms and soil structure is amazing: very brittle, nicely structured and just LOADED with earthworms.
Show threadBenedikt HaugMay 19, 2025
7/9 Important takeaways/disclaimers: woodchips had been worked into the soil initially with a plough and/or a rotary harrow (I cannot remember, sorry!) as the system won't integrate the chips quickly enough otherwise. For the rest, they were working with #NoTill methods, using a roller-crimper to controll weeds and destroy green manures so that the soil-microbiology remains intact. Last but not least: it's very warm there and the soils receive irrigation which leads to a high microbial activity throughout the year. If and how it works under more Northern conditions remains to be seen (in fact, I will start a small pilot trial on my own farm this year!)
Show threadBenedikt HaugMay 19, 2025
8/9 Next to that Pierre is an expert when it comes to soil fungi like arbuscular #mycorrhizal funghi (AMF) but also soil bacteria, he's particularly good at genetically fingerprinting and quantyfing different taxa. I have again learned a lot from him. He has published a lot of work on the crop-soil-microbiome interaction and we'll surely collaborate in the future as I want to integrate #breeding for improved soil-microbiome interaction as a research line in my work at #WUR.
Show threadBenedikt HaugMay 19, 2025
9/9 If you're curious on my pilot trial with the woodchips here in the #Netherlands, please let me know then I'll post here on it.
Show threadBenedikt HaugMay 19, 2025
@earthworm @mrillig
Show threadBenedikt HaugMay 19, 2025
ps. There is a manuscript in proparation from Joan's group and I'll post a link to the article once it's been published here