Holger Huffelmann is a trained, state-certified and learned farmer. At the Haus Düsse Trial and Training Centre, Bad Sassendorf, Germany, he is responsible for agricultural field operations as well as planning and implementing the arable trials. He is still fascinated by the range of diverse tasks on the farm, in the trials and in the office. At Haus Düsse, he is trying to counter the increasing administrative and organisational workload created by legal regulations – like fertiliser documentation – by using digitalisation and automation processes.
One effective tool, Mr Huffelmann believes, is NIRS technology. It can also help mitigate environmental problems, increase society’s acceptance of agriculture and ultimately save costs. Over the past four years at Haus Düsse, Mr Huffelman has been testing how precise manure application using near infrared spectroscopy (NIRS) technology affects wheat yields.
We speak to Mr Huffelmann about the programme:
How did the idea for the slurry application trials come about?
As part of the Water Framework Directive, we have already experimented with NIRS technology at the Chamber of Agriculture, measuring the amount of nutrients in the slurry as it moves between the storage tank and the slurry drum. However, this way we only get a total value for the nitrogen (or other nutrients) contained, which is then applied to a specific area from the drum content. Therefore, we came up with the idea of using NIRS technology to measure and control the applied amount in-line.
What has come out of your wheat field tests so far?
The aim was to find out whether we can fertilise more accurately with the help of NIRS than we can through testing the slurry once or twice. The test was set up in three strips side-by-side as follows: In the first strip we applied slurry at a rate of 50kg/ha of ammonium N, measured using NIRS, in a second strip we applied it at a rate of 66kg/ha total N, and in a third strip we applied a constant 23.8m³/ha . This also corresponds to 50kg/ha of ammonium N based on a slurry quick test.
We were able to determine that, compared to the constant volume flow by m³, the total-N variant based on NIRS delivers a yield advantage of approx. 3%, and the ammonium-N option delivers an advantage of 4-5%. With an average yield of 7.5-8.0t/ha, this means additional revenue of €40-70/ha (£35-60/ha). In addition, the targeted N application makes the supply to the crop more uniform and reduces lodging. Another advantage is that the farmer can better comply with fertiliser regulations and keep up with the relevant documentation.
Can you tell us a little more about your trials and investigations?
We have been conducting slurry trials in wheat using NIRS technology for four years. Over that time, we have come up with different trial designs for both maize and wheat. In the 2021 season, we will also investigate pre-sowing application in maize for the first time.
When applying the slurry, we do not dose based on cubic metres, but on the amount of nitrogen it contains. There are several options for this: Firstly, according to the travel speed. This means that we drive a little faster with thick slurry and correspondingly slower with thin slurry. On the other hand, the application rate can also be regulated via the pump speed, in that the pump rotates faster when the slurry has a higher nutrient content and slower when the content is lower. So far, we have adjusted the slurry application by changing the travel speed. In the trials in 2021, we will initially make adjustments by changing the pump speed. We hope this will reduce the time delay between the ingredient quantity measurement and the actual application, which should lead to more accurate results.
How do farmers view this technology and is it officially recognised?
NIRS technology is also used in the analysis of animal feed and is therefore not unknown to farmers. However, they are still somewhat sceptical about the technology. On the one hand, this is because they know and trust traditional laboratory analysis. On the other hand, there are manure-exporting and manure-receiving farms. The receiving farms have a great interest in knowing exactly what is in their manure. For the manure-exporting farms, on the other hand, it is simpler and more cost-effective to work with official figures. Because of the large number of samples, both NIRS and the official rule-of-thumb figures can provide good average values.
However, NIRS offers the advantage of continuous adjustment in the application rate. Slurry and digestate can be very variable products, depending on what they are made from, and the nutrient content can deviate greatly from average values. When spreading slurry or digestate using NIRS technology, a certified calibration curve approved for the substrate must therefore be stored so that the values are recognised for legislative documentation.
Furthermore, I also see an acceptance beyond agriculture and among consumers, because I have the impression that everything that is regulated by technology and not by humans is seen as more accurate and reliable in many areas. For example, we trust navigation systems and do not question when we are shown a certain route or a traffic jam. I can imagine the day when this is the case with a certified NIRS technology.
What would be the fastest way for this technology to enter practice?
I can see NIRS being used more by contractors than by farmers. Contractors, as service providers, can take over both the slurry spreading and documentation. On the one hand, the technology is associated with costs, and on the other, there are constant changes both in the application technology – for example from drop hoses to injectors – and in the sensor technology. Only larger farms can afford the speed of change. Added to this is the high workload of livestock farms.
Furthermore, contractors can offer additional services like creating application maps, bringing even greater benefits to their clients. Many farmers can also see the advantages of using a contractor. For example, they don’t have to invest in such technology before a generational change is due. And the additional application costs are only incurred for the area worked, while the financial advantages (through higher yields) determined in our trials can still be felt.
Today, the Haus Düsse Trial and Training Centre serves the North Rhine-Westphalia Chamber of Agriculture as a central educational and trial facility for animal and plant production. The Haus Düsse site is also home to other agricultural facilities.
- 300ha farmland
- 10ha grassland
- 22ha woodland
- 17ha paths and buildings
- 290 breeding sows
- 3,350 pig-fattening stalls
- 140 dairy cows with offspring
- 60 fattening bulls
- 5,000 laying hens
- Fattening poultry depending on requirements