In agriculture, improving heavy clay soil mainly means loosening the structure and keeping it stable. Then rain soaks in, the root gets down deep and reaches the water the soil stores. That works through loosening, lime, humus and the right timing for field traffic.
What characterises heavy clay soil
- The fine pores store a lot of water. But they hold part of it so tightly that the plant cannot get at it.
- It compacts easily, especially when driven on wet. A plough pan keeps water on top and roots out of the subsoil.
- In heavy rain the surface slakes and forms a crust. The water then runs off instead of soaking in.
- When dry it turns hard and cracks.
- In spring it warms up slowly, and the window for cultivation is short.
- The advantages: it holds nutrients well and delivers high yields when the structure is right.
Improving heavy clay soil: the measures
Soil analysis and spade test
The lab report shows pH, humus and nutrients. The spade shows what the lab cannot see: where the soil is compacted and how deep the roots get.
Do not drive on it when wet
Most compaction happens on a few wet days. Low tyre pressure and wide tyres spread the weight. If possible, wait until the soil has dried off.
Break up compaction
A plough pan is loosened when the soil is dry. After that, deep-rooting cover crops keep the loosening open. Without them the soil soon settles again.
Lime
Calcium binds the fine clay particles into stable crumbs. The soil becomes looser, slakes less and lets water soak in better. The amount depends on the pH in the analysis.
Promote humus and soil life
Cover crops, manure and compost feed soil life. Earthworms create channels through which water and roots get down deep.
Keep the soil covered
Plant cover or mulch intercepts the raindrops. The surface does not slake, and the water soaks in.
Soil conditioners and a water store in the root zone
Soil conditioners improve soil structure from the first season. A water-storing granule holds additional water right at the root.
Read more: Soil improvement · Improving sandy soil
What PowerGelee does on heavy clay soil
PowerGelee is a water-storing granule with high-quality active soil conditioners for conventional agriculture. On heavy soil the water store matters less than on sand, because the soil itself holds a lot. The soil conditioners matter more here: they improve soil structure and keep nutrients in the root zone. The granule also holds water right at the root for the dry weeks. Every blend also contains stable humus that is available immediately.
PowerGelee does not fix compaction. A plough pan has to be broken up first, otherwise the root does not reach the store. The blend follows your soil analysis, is worked into the root zone once, about 150 kg per hectare on average, and has a half-life of about 5 years. We do not give a yield guarantee.
More on water-storing granules · View the products
What this brings the farm: time and money
A soil that holds water and nutrients needs less topping up. You go out less often to supply water and nutrients. Those are tractor hours, diesel and machine wear you save. On top of that come more evenly supplied stands that get through dry weeks better. See field comparisons · Testimonials
If you have a lab report of your soil sample, you can upload it to us. We tell you without obligation what your soil lacks and which blend suits it. We deliver to Germany, France, Austria and Switzerland, and to other countries on request.
Frequently asked questions
How do you improve heavy clay soil in agriculture?
Break up compaction, do not drive on it when wet, lime according to the analysis and promote humus and soil life with cover crops, manure and compost. Soil conditioners improve the structure further.
When can heavy clay soil be worked?
When it has dried off. Take a handful of soil from working depth: if it breaks into crumbs when pressed, the time is right. If it can be rolled into a sausage, the soil is still too wet.
Does adding sand help against heavy clay soil?
In the field, practically not. It would take quantities that cannot be paid for across the area. Lime, humus and loosening act on the structure and are the usual route.
Do water-storing granules help on heavy clay soil?
Less than on sand, because heavy soil holds a lot of water itself. It holds additional water right at the root. The condition is that the soil is not compacted.
Current soil moisture data
Two public services show how dry the soil currently is in Germany:
- German Drought Monitor, Helmholtz Centre for Environmental Research (UFZ): drought status of topsoil and total soil, updated daily
- Soil moisture viewer, German Meteorological Service (DWD): soil moisture by crop, soil type and depth (in German)