Monday, October 26, 2009

Field of Dreams - The Soil Food Web

Jay Fuhrer, NRCS Office, Bismarck, ND

Do you ever remember the film Field of Dreams with Kevin Costner? Well if you do you may remember the phrase "if you build it, he will come". Well this is the analogy Jay Fuhrer uses for soil health building microbes.

Jay works as head of extension work in the Burley County office of the Natural Resource and Conservation Service Office in North Dakota. My instinct tells me that this office is a bit of a rare breed in that they have such a healthy two way relationship with some the farmers in the area.

In fact Gabe Brown and Gene Goven (see other posts) to name two seem to be constantly cross fertilising ideas within the NRCS office to find innovative ways of maintaing the environment as well as increasing productivity. Gabe and Gene both hung around the office when I was there, feet on the table, lobbing around new ideas with other staff - an environment conducive to innovation, and a culture that no idea is too stupid . I imagine very few ideas are dismissed before being considered from various angles.

Jay Fuhrer's big interest at the moment is the potential of soil health to improve productivity. "We don't know half, Will" he said "we don't even know 1%." Jay has studied the Soil Food Web data with Elaine Ingham (google her) and is trying to apply it to agriculture and seeing what happens. I found this particularly refreshing as for me a lot of the soilfoodweb stuff has always seemed a bit far out - but fundamentally its just about biology of microbes, so the principles of it were brought into focus by Jay.

The latest project is to maximise the soil health and also play around with things like compost tea, multiple cover crops and to see what happens. Jay took me on a trip around the state and to a presentation in Fargo, Eastern ND we went to a Soils Conference. When Jay does his presentations its fair to say some people do a bit of eyebrow raising. Some in the audience had some trouble amalgamating their knowledge of the physics and chemistry of soil science with the burgeoning biological side. Thats ok with Jay - he doesn't know what he's doing all the time he says, but unless you try these things you don't know what you can or can't do. One thing that I did notice is that talking of soil biology in agricultural arena seems to be considered a bit of a soft or effete discipline. Therefore those who like their information with charts of two columns proving a hypothesis are left frustrated as there is so much left unproven. That said there are plenty who are getting it or as Jay says "they're on board."


Here are some things which I noticed as interesting when listening to Jay's presentations or when just chatting:
  • The aim is to build sustainable soils. That is building soil aggregates with low fossil fuels
    If we keep armour (soil cover) on the surface we can do great things - it also keeps it more weed free.
  • Try to promote the use of cover crop or forage cocktails - and therefore provide a balanced diet for the livestock. The above ground ground ones and the below ground ones.
    From the soil food web data. A forest soil will be fungally dominant and low in bacteria. A Prarie soil would be bacterially dominant and low in fungus. The ideal balance is as close to 1:1 - for to maximise crop production you need a balance. He told me when they tested Gabe Brown's farm they found it was about 2:1 bacterially dominant - this may be as close as they can get a farm soil. At this 1:1 ratio there is more weed suppression, less compaction and higher nitrate availibility. That said to have the fungi you need lignin so maybe its better at 2:1 than 1:1
  • Cover crops cocktails are seen as vital for no till cropping systems. Firstly they produce much more than monocultures or two species. Much, much more actually in lbs/acre. This means there is more food. Cover crops also accelerate biological time - the roots and exudates etc. speed up the production and respiration of all the microbes.
  • You need to consider the Carbon:Nitrogen ratio as well. Common no till crops such as corn (maize) and wheat and carbon heavy. A designed cover crop will bring the N ratio back up.
    A cover crop also maintains pore spaces in the soil. They know that traction of vehicles and rain compresses pore spaces and pockets and this will stop microbes accessing the nutrients. Nodulation of legumes is also inhibited where there is soil compaction.

There is a lot more to say but Jay really brought some things into focus. Not least that farmers need not be afraid of finding more about soil biology - the potential of it is exciting. "It's basically about who eats who, Will" says Jay "like us, soil creatures respond to a balanced diet and if they get that balanced diet they will repay you in spades. Its like sending a son to college, you get him a place to live, make it comfortable, stock his fridge with beer and then leave him get on with it, its the same with soil critters".

"We are constantly seeking to evolve" says Jay "I started my job designing drainage watersheds. They'e pretty much redundant now thanks to No Till. There was a time that I wanted to just get farmers no tilling to save soil, then I wanted them to only use disc drills to move minimum soil, then I wanted them to use a cover crop species, then it was two covers in a mix, now its multiple cover crops and next it could be soilfoodweb and composting, who knows?"


Jay told me that he could retire soon but has decided that things are getting pretty exciting around there so to use another baseball linked analogy he said "I wanna slide into first base when I've really run out outta gas!"

Better just keep practising that sliding technique in the back yard for a few years longer yet then, Jay!
 

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