The demo garden is situated on the premises of Gut Sitzenhof adjacent to the FITcentre and the factory premises of the HORSCH Maschinen GmbH. It comprises demonstrative experiments as well as special tests with regard to various questions and problems. The test fields were established in 1997 and, since then, have been used to exchange experiences with farmers and to answer agricultural questions.
The fields are divided into a 13.5 hectare demonstration area and a 6.5 hectare trial plot. Up to 300 plots (3 m wide, 50 m long) can be established in this generous demo garden. In the front fields a long-term test concerning cultivation intensity has been put in place. This test has been running since the establishment of the demo garden and covers all sectors from intensive tillage with plough or deep cultivation over minimum tillage to direct seeding.
The remaining plots are used to try and explain various questions regarding cultivation and sowing.
The rock material present at the site Sitzenhof is shell limestone which was formed from fossil calcareous deposits approx. 243 to 235 million years ago. The soil type is brown earth that resulted from a browning and a simultaneous enrichment with humus of the top soil in a humid climate. The soil texture is sandy loam with a clay content of 25 per cent.
A specific characteristic of the site are the changing soil conditions with soil points ranging between 28 and 42 and the high ratio of stones.
In this region, traditional farming with commercial crops as well as livestock farming is prominent. The agricultural fields in the region and at the site Sitzenhof are used for the cultivation of cereals and rape that are marketed traditionally and for the cultivation of cereals, grain maize and maize for silage for the use in livestock farming and for energy production in biogas plants.
The demo garden is situated in the warm temperate rain zone of the medium latitudes, in the transition zone from the Western European maritime climate to the Eastern European continental climate with a slight tendency towards the continental one that is marked by colder winters and hotter summers with less humidity.
This tendency is supported by the average annual temperature of 7.5°C which is 0.9°C lower than the German annual average. With a medium annual rainfall of about 670 mm in the observation period, Gut Sitzenhof is slightly below the German annual average. During the past five years rainfall has settled down clearly above 700 mm per year.
The long-term test “cultivation intensity“ that was put in place in 1997 first and foremost serves to observe the annual effects of different cultivation types. The resulting findings are used to evaluate the different initial situations for cultivation.
The test results can be summarised as follows:
1. Cultivation intensity depends on several factors. The main factors are the type of crop, the condition of the soil before cultivation (compaction, tracks) and the moisture at the time of cultivation.
2. The results show the tendency that, in many years, deep loosening brings about yield benefits
3. The maximum loosening depth depends on the thickness of the topsoil (at the site Sitzenhof max. up to 20 cm, then it gives way to the subsoil); on deeper sites loosening at a depth of 35 – 40 cm can be reasonable; on shallow, stony sites the maximum loosening depth often is limited to 10 to 15 cm.
4. Loosening depth cannot be generalised, but has to be adapted specifically for every site, every crop and the humidity of the soil.
5. Basically a certain degree of cultivation guarantees a good yield; at the site Sitzenhof direct seeding results in lower yields, especially for winter rape.
6. Possible savings in cultivation start with consequently avoiding compactions and tracks.
7. Underground fertilisation compared to wide spread fertilisation considerably supports the young population in difficult years and, thus, can have important advantages for the population development, e.g. under the extremely wet conditions of the autumn sowing of winter rape in 2010.
Also from the economical point of view cultivation intensity is an important parameter to optimise unit costs. But also from this point of view only yields at a constantly high level guarantee good farm profits.
Since 2003 the experiences with regard to cultivation at the site Sitzenhof have been completed by an extremely heavy site in the Czech Republic (East of Prague). This second site will be presented on the occasion of the practical field days 2011 and the experiences we made there will be discussed.