Delving into Danish soils
Teagasc specialist Ciaran Hickey travels to Scandinavia to assess how local grain growers manage their min-till operations
Tuesday August 04 2009
Last November I travelled to Denmark to visit the farm of Hans Dahm, who is chairman of the Danish organisation of min-till farmers.
They founded the organisation in 2000, and from a base of 80 farmers they now have 250 members.
Some are specialists in min till as they have more than 10 years experience with the system. This is a big attraction to new members as the old hands can advise novices on the pitfalls of the system.
Indeed, one could not help feeling envious of the level of support that min-till farmers in Denmark enjoy.
As an organisation they are looking at further improvements to the system and they see the use of GPS, which will facilitate the use of the same tramlines in fields each year, as the next big advance in this cultivation system.
They have found from research that by using the same tramlines they can minimise compaction and hence make cultivation more efficient. Yields are increased as a consequence.
Hans had just secured a deal to lease a further 175ha and this was going to be his biggest challenge for the near future.
Short
He was concerned that his machinery setup would fall short of the mark and explained that he would not be rushing out to buy a whole new system.
Instead, he aimed to hire in equipment as it was required. For example, he showed us photos of a Fendt 936 that he hired in for one month at a cost of 15,000K (€2,068), which enabled him to use a bigger rented cultivator that was more suited to working the heavier type of soil on the newly rented land.
The entire farm consisted of 685ha (1,692ac) of which 250ha was owned, 260ha was rented and in the system for a number of years, and his 175ha of new land that was not in good condition, with its soil structure in a poor state.
This was where we were first introduced to Bente Andersen, a special adviser for min-till farmers.
Immediately, we could sense that this lady had huge practical experience of the system in Denmark and we later found out that, with her husband, she also had a large arable and pig enterprise.
We went to the field to examine the soil structure and it was clear to see that it was in excellent order, with no signs of compaction and a lovely crumb feel to the ground.
She told us that it took a very well organised and dedicated farmer to make the system a success and the main skills were to understand what was going on beneath the crop rather than just looking at what was going on above the ground.
Hans went on to explain how his system needed about three good, fine days before he could go drilling without any damage being done to the soil.
He said it was frustrating to see other farmers on a plough-based system working away, but explained that once he got going he would achieve high work rates and catch up.
In 1999 Hans went to visit the Horsch machinery plant in Germany and this was the start of his interest in min till, and in 2001 he did not plough anything.
The rotation on the farm was wheat (200-250ha), spring barley, oilseed rape, peas, grass seed and, for this year, he will have maize for the first time.
Hans ploughs in the grass-seed portion of the rotation and I was impressed that even though he was a min-till enthusiast, he did not rule out some ploughing when needed.
Although Hans has found that min till has been central to his farm business, he also moved towards improved marketing of his produce. For example, his barley went to Japan last year to make beer.
One of the main things I took away from this visit was the use of second or after crops, such as mustard. The reason they were using so much of these was two-fold -- to improve soil structure and because erosion is a big worry in Denmark.
Bente Andersen explained that by using these crops there would be no need to sub-soil the land. In fact, they put very little faith in the practice of sub soiling land in Denmark. The weather had to be perfect before, after and during the sub-soiling process and she felt that it was hard to work into the programme.
I was shocked to hear that IPU had been banned in Denmark for the previous 10 years due to the risk of leaching and they were very upset about it at the time, but Klaus Johansen (Danish advisory service) explained that if something had this type of risk it was better to be abandoned, and it forced scientists to come up with a safer alternative. They found this in the product Boxer, which has the active ingredient prosulphorcarb.
Stubble
Hans gave us a short summary of the growing season, which started with harvesting on August 10-15. He emphasised the importance of short stubble, 10cm if possible. I was surprised to hear that he did not chop all the straw and actually found that it was not hugely advantageous to the system. He added that its value as a saleable product to neighbouring farmers was also a factor.
His other problem with straw was that the combine had a 9m header and the straw chopper was unable to spread the straw evenly over the 9m.
Directly after harvesting they would cultivate at a shallow depth of 3-5cm, just enough to break the crust on the soil and create the maximum germination conditions.
They felt that going deepcould impede some weeds and volunteers from germinating.
Then, 14-20 days later they spray Roundup at 0.5-1 litres/ha and then 2-3 days later they cultivate for a second time at 12-15cm to break any compaction pans and also to get a nice tilth for sowing.
They would drill immediately after cultivation and achieved work rates of 2-3ha/hr. He emphasised at this point how the rising fuel costs were a big concern. He uses a New Holland TM190 as the main tractor and this consumes 40-45 litres/hr.
Given that he cultivates 4ha/hr this equates to an overall fuel use of 10 litres/ha. For seeding, the overall fuel use is nine litres/ha.
Hans assessed the option of renting a John Deere 8530.
Buying this tractor was not feasible, but at a fuel use of 28 litres/hr while cultivating, renting it in order to reduce the cost of establishment was being reviewed.
After drilling, the system comes more in line with conventional husbandry, with weed control in the autumn and fungicides in the spring/summer period.
However, one notable difference was that the drill being used had been adapted to put down liquid fertiliser under the seed.
Hans had great faith in this system as the crop was very vigorous coming out of the autumn period.
This, combined with the 70-100kg of soil N that was trapped by the green crop -- of which 50pc was available to the wheat crop -- made it possible to get close to the optimum N allowance. I was surprised to hear that the Danish government would calculate the optimum N level for maximum yield and then allow the farmers to use 80pc of this total.
But one could not help feeling that farmers have become more efficient in their N usage as a consequence of tighter regulations.
The green crop was sown after harvest by an auto-cast system mounted on the cultivator. At a rate of 8kg/ha and a cost of €8/kg, this equated to a cost of €25/ac to achieve 30-40units of N/ac.
This is not cheap, but when you take into account the restrictions on fertiliser and the added soil benefits it is an interesting practice.
- Ciaran Hickey
