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Annual Horsch seminars – advantages from intercrop


Traditionally, in Sitzenhof, in the scope of annual meeting with farmers – HORSCH SEMINARS – all seats were taken. In the meantime, HORSCH seminars became a fixed point on the agenda of training events, visited by German-speaking clients and farmers. While virtually all the speakers addressed the practical side of digitalisation in broad meaning of this word, the day started with a lecture on plant cultivation.

The lecture was given by Dr Wilfried Hartl, director of the Organic Research Institute in Austria, that has conducted research on ecological cultivation, independent of livestock since 1979. It mostly concentrates on culture cycles, availability of nutrients and bio-diversity, posing the following question: “How can one apply fertiliser very precisely in ecological sector?”. Its explanation: “In eco-agriculture fertilisation takes place in soil. Plants has found smart ways to feed on soil. Three worlds of organism has impact on soil alimentation: producers (CO2 and O2), consumers (animals, human beings) and decomposers (edaphones, fungi, bacteria). According to dr Wilfried Hartl, this knowledge forms the basis of understanding of eco-farming.

This means that if you have a natural fertiliser, you can easily pursue eco-farming, but what is the situation on farms without animals? “After the lapse of two or three years without manure, capacity falls by two thirds, due to insufficient energy supplied to soil from the outside”, explained the scientist. If you do not have animals on your farm, which animals can supply necessary energy to soil? “Soil life (edaphones) is the key to success”, explained dr Wilfried Hartl. There is a number of big conversion units (LSU) of nematodes, earthworms, etc. in soil.

“If you look at soil life in the perspective of farm animals and feed them adequately, you may cultivate soil ecologically without livestock”.

In 1983 in Austria attempts were started of food composting. It turned out that in the composting process quite a lot of carbon penetrates soil as “permanent humus”. But how can one insert additional humus to soil? By intercrops, perhaps? “Definitely yes”, responds dr Hartl.

Intercrops are suppliers of nutrients and carbon, in particular in the family surroundings of dr Hartl, in the south-eastern Austria, where it is often very dry, which results in intercrop cultivation being difficult, however, not impossible. What brings good effects, is correct soil cultivation. At the same time, as an expert, he warned: „without plough does not automatically mean  an increase in humus level!”.


What is important is pore volume amounting to 40 to 60%, since soil life and roots live there. Continuity of pores is also of importance, because, e.g. flooding can be avoided. Water inaccessible for plants should be avoided, since hair on plant roots are unable to reach them. The largest volume of storage of water is characteristic for medium-sized pores, in particular, in loess. Clayey soil is characterised with 60% of pore volume, and at the same time 40% of very small pores filled with dead water. Due to the fact that there are no machines that contribute to creation of pores in soil, soil organisms need to assist plant roots.

Vegetation ensures more roots in the soil. Dr Wilfried Hartl recommends vegetation free from leguminous plants in order to limit infection pressure. However, 20% share of leguminous plants is not a problem (decision depends on field location).

Particularly on dry areas intercrop should be sown directly behind the combine harvester, so that – as far as possible – water losses can be avoided. In such cases often every hour counts. In case of late vegetation (not very developed plants) C to N ratio is low (below 10), which means that nutrients are available as quickly, as in the case of manure, and, for example, Phacelia has C to N ratio exceeding 60. It is good for creation of permanent humus, however, it is weak in terms of quickly available nutritive humus.

Our interlocutor added: “a farmer should think thoroughly what the purpose of vegetation is”. His conclusion was as follows: if roots can develop without contact with  dense plough pan, the farmer did everything right!