Sunday, 11 December 2011
Cultivating a 'Direct Approach'
On Friday 10th December I was invited by UAP to go and listen to a talk all about Direct Drilling and Minimum Tillage. The talk was being give by Steve Townsend who runs a company called Soil First Farming. It was a really interesting and very though provoking, basically challenging us to rethink our philosophy on cultivation strategies across the different soil types on the farm.
The morning started in the classroom exploring soil and what it is made up of, sand, silt, clay with a few rocks thrown in on our hill and how these particles interact with each other and what we do to them when we cultivate. The best soils, and our best assets as farmers, contain 25% air, 25% water, 5 % organic matter and 45 % minerals (sand, clay and silt). Much of the morning was talking about carbon and how we can alter and increase the amount in the soil. Carbon is contained in crop residue and dead soil bacteria, fungi, worms etc and how do we increase those levels in the soil? We spoke about cover crops, between winter and spring crops, like beans, oats, mustard even peas. These crops would feed the soil organisms when they die and lock up nutrients, to be stored for later crops. This seems really logical to me as it will not only increase the soil organic matter but reduce the risks of soil washing off down the hill during periods of heavy rain through the winter. We'll be trying that next summer!
In the field we looked at soil structure, digging down to find the anaerobic layer (where last years crop residues remain uneaten by the soil microbes. We looked for evidence of worm activity, worm casts on the surface and worm tubes through the soil. These are very helpful to farmers as they allow water to seep through the soil profile but also provide routes for roots, heading down in search of water. We looked at cultivation depth, anything over 4" was too deep, (as long as there is no soil compaction that the roots of the crop can't deal with). A root can exhort the downward pressure of 200-300 psi when growing through the soil. Ideally cultivating at no more than 3" will increase the worm population, keep the trash on the surface and speed up cultivations. Again another point to experiment with next summer. We talked about weed control and reducing fertiliser applications, about straw incorporation and stale seedbeds, as I said earlier it was a very interesting day.
Finally we headed back to the farm workshop to have a look at Chris's new direct drill. We have been dipping our toes into different direct drilling techniques this summer so it was good to hear someone Eese's experiences. I went away with two main targets that I will be putting into practise, firstly, getting more organic matter into the soil and secondly making better use of cover crops where we are growing crops in the spring.