The goal: to reduce nitrate
The amended ‘DüMV’ [Fertiliser Ordinance], which came into force in 2017, had a worthy goal. Its aim was to reduce the amount of nitrate in the groundwater. For many years now, the groundwater in some regions has been polluted with this harmful nitrogen compound which can be put down to the excessive use of animal-based fertiliser, primarily liquid manure. The problem: the legislator has not only regulated the use of liquid manure but put all organic fertilisers into one basket so to speak. This generalisation has led to compost users having to cope with a whole load of red tape. And all this even though natural compost not only protects the groundwater and improves the quality of the soil but also helps to store water in the ground. An important factor looking at the lack of rain we have had over the last few months.
Compost has a whole host of advantages
People have been using compost to improve the quality of their soils for centuries. This natural product increases humus levels in the soil and, by doing so, helps prevent climate change. Compost conserves supplies of nutrients and promotes biodiversity. And it has another key property – something that is becoming increasingly important looking at this summer’s drought. Compost can retain around five times its own weight in water which can then be passed on to the plants. The amount of water able to be stored by mineral fertiliser is much lower and liquid manure, of course, even lower still.
The ability of compost/humus to retain water
Source: VHE (soil association), vhe.de
The new law is heading in the wrong direction
What’s more, natural compost does not contaminate the groundwater because the nutrients are released slowly into the soil. Which is why it is all the more difficult to understand why the use of compost is effectively being questioned by law as a result of the ordinances drawn up by the individual German states regarding nitrogen levels in compost – something that really has more to do with liquid manure and mineral fertilisers. More and more environmentally aware farmers are fertilising their fields with natural compost to make the most of these advantages. In an interview with REMONDIS AKTUELL, Peter Zillikens, a farmer from Bornheim, explains why he prefers to use compost made from recycled organic waste.
Farmer Peter Zillikens uses RETERRA compost to fertilise his fields
Interview
REMONDIS AKTUELL: Mr Zillikens, the practice of using liquid manure as a fertiliser is being heavily criticised at the moment because of it contaminating the groundwater with nitrate. Why do you believe that using compost instead is a good way to improve soils and protect the groundwater?
Peter Zillikens: The actual fertiliser is bound to the solid matter in the compost. This means that it can’t be washed out and is effectively released into the soil in portions. Besides this, the humus content has a positive impact on the soil.
REMONDIS AKTUELL: It’s possible to see exactly which areas have been fertilised with compost over a long period and which haven’t – especially in extreme weather conditions like the current heatwave. Is the fact that compost is able to retain water an argument for using it as a fertiliser?
Peter Zillikens: What’s clear is that everything possible has to be done to counter such extreme weather conditions. Using organic compost as a fertiliser is certainly an important tool here.
REMONDIS AKTUELL: It’s far more work for you to use compost than simply buying mineral fertiliser and quickly spreading it over your fields as and when it’s needed. Why are you prepared to take on this extra work?
Peter Zillikens: There are three good reasons. Firstly, compost is good value for money. Secondly, it’s not normally a problem to spread it on the fields as there are some highly efficient contractors happy to help out here and, thirdly, public opinion plays a very important role. Using natural compost rather than artificial fertiliser increases the value of our products in every possible way.
REMONDIS AKTUELL: The Fertiliser Ordinance primarily regulates compost according to its nitrogen and phosphorus content. Other components are far more important as far as fertilising soils are concerned, such as the humus, lime content, micronutrients and the improved soil biology. What factors are most important for you here?
Peter Zillikens: The main reason is that compost allows me to control the way vital nutrients are spread over my fields. At the same time, it feeds the creatures in the soil enabling them to reproduce – something that is also really important for improving soil quality. Soil tilth, i.e. the overall quality of the tilled soil, noticeably improves, not least because compost also has a positive impact on crumb structure. And it also minimises the risk of soil capping.
REMONDIS AKTUELL: What expectations do you have of your suppliers?
Peter Zillikens: Being a farmer, the quality of the product is really important as are punctual deliveries, of course.
REMONDIS AKTUELL: What expectations do you have regarding the quality of the compost?
Peter Zillikens: The compost must be of a good quality. What’s more, it’s really important that it doesn’t contain any contaminants. It should have a uniform amount of dry content as the soil shouldn’t become too dry after the compost has been spread to keep dust levels to a minimum.
Image credits: Image 1: iStock; 73488975, Urheber: Sasiistock, Image 2: © REMONDIS
