Targeted irrigation in organic farming to increase productivity and nutrient efficiency

BÖLN - Targeted irrigation in organic farming to increase productivity and nutrient efficiency

Project goals

The change in precipitation distribution caused by climate change, with pronounced dry phases during vegetation and high precipitation in the winter months, influences plant growth and the nutrient balance. In addition to reduced nutrient availability during dry periods, nutrients are also lost through leaching and erosion. It can be assumed that these effects are more pronounced in organic farming than conventionally due to the limited supply of nutrients from outside and, for example, competition from diseases, pests and weeds.

Strategies for avoiding nutrient losses in organic farming are largely known and available in practice. However, there is still a lack of knowledge on how strong the influence of water supply, in particular water shortage, is on nutrient dynamics in critical phases of yield formation in organic farming. In addition to the reduced nutrient availability due to the restriction of mineralisation and root growth as a direct effect, drought stress also leads indirectly to lower N2 fixation via the yield reduction of legumes and, as a consequence, to lower N supply into the system and to lower yields of non-legumes. Against this background, the question of whether crops in organic farming are suitable for irrigation has not yet been adequately answered.

Effects of drip irrigation on the growth of faba beans, Weeze 2029
Effects of drip irrigation on the growth of faba beans, Weeze 2029 © Daniel Neuhoff

Innovative methods of water and nutrient supply

The overall objective of the project is to increase productivity in organic arable farming at crop type and system level (crop rotation) by investigating the relationships between water supply and nutrient dynamics for the legume - cereal crop rotation link and providing information on irrigation suitability. To this end, field trials will be carried out on experimental and practical farms using innovative methods of water and nutrient supply for forage and grain legumes as well as cereals and subjected to a systematic overall and inter-farm evaluation. The following sub-goals are being pursued in detail:

Quantification of the water shortage

Quantification of yield gaps induced by water shortage, i.e. water-limited yields
Determination of the influence of differentiated nutrient supply (N and P) with enriched digestate composts and recycled P fertilisers on yield performance and their interaction with water supply
Measurement of the N2 fixation performance of forage and grain legumes as a function of water and nutrient supply in situ and calculation of NdfA values
Systematic analysis of resource efficiency by calculating the nutrient uptake and utilisation efficiency of the applied fertilisers with differentiated water supply
Quantification and evaluation of irrigation and fertilisation effects on nutrient balances at field and extended farm gate level
Calculation of the economic irrigability of the crops analysed, taking into account the system effects, in particular the N input through N2 fixation
Derivation of practical recommendations for a water-controlled increase in productivity.

Working fields of the AOL

  • INRES-AOL is responsible for coordinating the overall project and publicising it.
  • Field and practical trials are carried out at several locations.

Project titel: Targeted irrigation in organic farming to increase productivity and nutrient efficiency
Acronym: BÖLN
Duration: 01. 12. 2018 - 30. 11. 2021

Bundesanstalt für Landwirtschaft und Ernährung Bundesprogramms Ökologischer Landbau und andere Formen nachhaltiger Landwirtschaft (BÖLN)

Project partners:
  • Prof. Dr. Stephan Siebert & Dr. Rüdiger Jung (Georg-August-Universität Göttingen, Abt. Pflanzenbau)
  • Institut für Landtechnik, Uni Bonn, Dr. Oliver Schmittmann
  • Projekt Leitbetriebe ÖL-NRW, Dipl. Ing. agr. Christoph Stumm (AOL)
  • DLG-Ausschuss für Ökolandbau (Dr. Jobst v. Schaaffhausen)
  • Kuratorium für Technik und Bauwesen in der Landwirtschaft (Ansprechpartner Herr Dr. Till Belau)


Avatar Neuhoff

Dr. Daniel Neuhoff


Auf dem Hügel 6

53121 Bonn

Avatar Döring

Prof. Dr. Thomas Döring

Wird geladen