Tour of the agricultural test field

The aim of this particular project was to assess the benefits of intercropping corn and pole beans compared to single-crop cultivation of corn. The weather conditions over the last few years – heavy rainfall in the spring and long periods of drought in the summer – have led to shortfalls in yields and poorer quality corn. Such problems justify the search for alternatives to corn cultivation as part of the production of fodder to feed ruminants.

Pole beans are rich in protein and, when intercropped with corn, improve yield and the quality of ruminants' diet. The protein content of the corn varies from year to year. With intercropping, the pole beans provide the protein that is vital for the animals' growth and development. The project demonstrated that it would be wise to sow these two crops at different times, which makes it possible to choose the optimal sowing time for each crop.

Undersowing in corn provides year-round soil cover and minimises nitrogen leaching in winter. In groundwater protection zones, this approach reduces soil erosion in problem areas – particularly those in Zones II and II-V1 – especially in autumn and winter, when rainfall is heavier, and provides better aeration of the top soil layer, thereby increasing water absorption capacity.

To enhance the effectiveness of groundwater protection zones and implement joint protection measures, the City of Luxembourg has entered into a regional collaboration agreement with the municipal administrations of Lintgen, Lorentzweiler, Steinsel and Strassen, which has led to the establishment of a Regional Collaboration Committee (Comité de collaboration régionale – CCR).

As part of the collaboration, a corn-weeding machine and a chain harrow have been purchased. The corn weeding machine can be used in full mechanical mode – which involves weeding between and on the rows of corn mechanically, without any additional application of plant protection products – or in semi-mechanical mode, which involves weeding between the rows mechanically, and on the rows chemically. Even in semi-mechanical mode, up to 70% less plant protection products can be used compared to when weeding is done only chemically. In 2022, the corn-weeding machine was used in full mechanical mode on 13.86 ha, and in semi-mechanical mode on 43.49 ha. In 2023, it was used in full mechanical mode on 17.97 ha, and in semi-mechanical mode on 49.94 ha. In 2022, the chain harrow was used on 26.12 ha, and in 2023 on 27.48 ha.