I’ve been at the World Congress on Conservation Agriculture for most of this week, hence no blog. It started off with a long and uneventful drive from Bismarck ND where road is so straight and empty that the main problem is resisting the temptation to surf the internet on my phone.The congress was OK, but not great. The talks were pitched fairly low, so didn’t come up with anything particularly groundbreaking. It was good to meet a lot of interesting guys from around the world though, especially some guys doing no-till sugar beet in Switzerland, whom I plan to go and visit.
Soil microbiologist Jill Clapperton gave an interesting talk where she pointed out that intensively tilled soils tended to have a higher ratio of inorganic:organic nitrogen, and it seemed like this favours weed species. I wonder though if by changing this you will just change the weed spectrum, rather than the overall quantity? Another of her stats is that 52% of microbial biomass is associated with roots. If microbes are the real driver for organic matter increases then it underlines the importance of constant soil cover with growing plants.
Another talk from a Brazilian worm specialist (the only one in existence, according to her) showed that we don’t do worms properly – theirs are more like snakes. A few of the panellists that day thought worm numbers were a good indicator of soil health, as they feed on soil microbes, as well as show that there is the “right type” of organic matter present. Some brief Googling shows that perhaps the best way to count worms is to douse the soil with mustard infused water. This should appeal to the inner hippy in everyone.
After a fairly poorly attended “Gala Dinner” one evening, there was a panel discussion about cover cropping from 3 American farmers. One of them farmed in what he called the “Mud Belt” – they get 38″ of rain a year and have heavy clays soils. He suggested that it was important to not sow cover crops too thick, otherwise the soil could not dry out quickly enough come springtime. This seems a good idea to me for people in the UK who are worried about exactly this problem. It would probably be easiest to achieve by using wide rows, with the added bonus of less diesel use.
One thing I have learnt is that within this little section of people there are plenty of zealots who know that they are right and everyone else is wrong – just the same as people who know that no-till doesn’t work etc etc. Conditions are different around the world and not all principles are applicable in all locations. Must remember to keep an open mind!
Here are a few quotes that I liked, but probably misremembered a bit:
“Increasing SOM from 1 to 3% doubles water holding capacity” – Dwayne Beck
“If a farmer applies 150kg/ha of N, that uses 3 times more energy than the tillage, seeding and harvest operations combined” – Dwayne Beck
“If you’re operating on the cutting edge then sometimes you’re going to bleed” – Dan Forgey
“If tillage controlled weeds they would all be gone by now” – Dwayne Beck
“If common sense worked all the time, we wouldn’t need science” – a lady on the R4 Food Programme podcast