Research project MIKODU

MIKODU - Crop sequences for optimized use of soil resources: combining allorhizous and homorhizous species for complementary root growth in topsoil and subsoil

The main objective of the project is reducing yield gaps in organic agriculture by optimizing the mobilisation of water and nutrients from the solid phase of the soil. The basis for this is promoting extensive root systems via creating a soil structure that is beneficial for soil microbiology and root growth. Catch crops and precrops will be grown that

  1. increase fine pores in shallow soil depths with homorhizous root systems or
  2. create access paths to deeper soil layers with taproots or
  3. integrate the effects of both root systems in mixed cropping systems.

With this optimization of subsoil structure, microbial activity and root extension of following crops into the subsoil will be increased, helping following crops to exploit water and nutrient reserves of the subsoil. Besides effects on soil structure, the different decomposition rates of the roots of the mixture partners will be considered, aiming at balanced nutrient supply for the following crops.

The subgoals of the project are

  • promoting root growth and nutrient acquisition of following crops via soil structuring by perennial fodder cropping with mixed growth of species with a pronounced taproot and species with intensive fibrous root systems (WP 1)
  • identification of catch crops that promote root growth of following crops as described above and additionally allow balanced mineralization of nutrients taken up over winter (WP 2)
  • use of intensively rooting pre- and catch crops to break up yield limiting soil compaction in agricultural headlands (WP 3).

The project results will then be demonstrated to farmers, to optimize crop sequences with respect to the utilization of top- and subsoil resources.

Our working group is part of AP2 and is conducting the species identification of the roots of the plants in the mixture via Fourier transform infrared (FTIR) spectroscopy.

The species identification and quantification of the roots in the mixed field stands is the goal of our work. The roots of the sole crops were used to create “artificial mixtures” of the mixture species. The artificial mixtures as well as the root samples of the field mixture were measured with the FITR spectrometer. The spectra of the artificial mixtures were utilized for establishing a model which was calibrated and validated (both external and internal). The software Quant 2 of Opus was used. Based on the model, the unknown proportion of species in the field mixtures were quantified. Hence, the percentage of the species could be determined with the model in the different soil layers.

Person in charge

Dr. Nicole Legner
Prof. Dr. Stefan Siebert


01.10.2018 – 31.12.2021


Federal Office for Agriculture and Food (BLE)
Funding code: 2818OE024