Summary
Summary
EIP-AGRI Operational Group “DaLeA” tested a clover-based permanent living mulch interplanted with arable main crops to suppress weeds, regulate soil temperature, retain water and minimise tillage, while assessing feasibility, transferability and economics across three years and three sites.
Photo gallery
Overview
Year of issue
2025
Implementation status
Completed
Contact
Agrarbüro Mittermeier
Location of the project
DaLeA pilot site in Rhineland, Germany (Rhineland-Palatinate).
Country
Germany
NUTS2 Code
Rheinhessen-Pfalz
Sponge measures implemented in the case study
Mulching
Cover crops
Minimum tillage
Objectives
Suppress weeds
Regulate soil temperature and reduce heat stress
Retain water and improve erosion control
Minimise tillage and inputs, reduce nutrient losses
Assess feasibility, transferability and economics
Regulate soil temperature and reduce heat stress
Retain water and improve erosion control
Minimise tillage and inputs, reduce nutrient losses
Assess feasibility, transferability and economics
Involved partners
| Authority type | Authority name | Authority role | Comments | Authority responsibility |
|---|---|---|---|---|
| Farmers | Agrarbüro Mittermeier | Implementation | Coordination, on-farm trials | Responsible |
| Research institute / University | Institute of Applied Plant Nutrition, University of Göttingen | Monitoring | research on evapotranspiration and CO₂ exchange | Supporting |
Site Information
Climate Zone
Cool temperate moist
Precipitation
737.00 mm
Temperature (°C)
10.00 °C
Elevation range
265
Vegetation class
Crops and clover
WFD Ecological status
Moderate
WFD Chemical status
Failing to achieve good
Water quality status
Nitrate leaching during rainfall events was a recurring problem in the region; the living mulch acted as a nitrogen buffer and reduced leaching in trials.
Design and Implementation
Project scale
Micro
Project scale specifications
Field-scale trials on multiple private farms in Rhineland-Palatinate
Project area
12 ha
Principles
Permanent clover living mulch as continuous cover
Lower external inputs and greenhouse gas footprint
Nitrogen cycling: leveraging clover fixation and reducing fertiliser demand
Soil temperature moderation and water retention
Erosion control
On-farm exact trials and knowledge transfer via field days and website
Lower external inputs and greenhouse gas footprint
Nitrogen cycling: leveraging clover fixation and reducing fertiliser demand
Soil temperature moderation and water retention
Erosion control
On-farm exact trials and knowledge transfer via field days and website
Favourable preconditions
Region normally has sufficient rainfall; effects in dry regions need study
Thermal moderation observed with mulch; drone thermal imagery showed cooler mulched zones than bare soil
Gas-exchange and ET measurements indicated less crop heat stress and net water savings despite added transpiration surface
Constraints noted: winter hardiness issues in freezing events, challenges for heavy erosion-prone crops like potatoes, summer crops harder to integrate; maize workable but water management still an issue
Where a prior cover crop existed, initial soil structure differences were not observed at that timepoint
Thermal moderation observed with mulch; drone thermal imagery showed cooler mulched zones than bare soil
Gas-exchange and ET measurements indicated less crop heat stress and net water savings despite added transpiration surface
Constraints noted: winter hardiness issues in freezing events, challenges for heavy erosion-prone crops like potatoes, summer crops harder to integrate; maize workable but water management still an issue
Where a prior cover crop existed, initial soil structure differences were not observed at that timepoint
Financing
Total cost
304685.00 €
Compensations
No
Policy and Governance
Policy description
Facing erosion and water stress issues, this project is a test and research site, with demonstrator value.
Land ownership
Private farms participating (one large full-time farm and one part-time farm explicitly mentioned).
Policy targets
Erosion Control
Target remarks
Soil health and biodiversity gains
Lower inputs and emissions
Water retention and erosion control
Reduced nutrient losses
Comparable profitability to conventional systems
Lower inputs and emissions
Water retention and erosion control
Reduced nutrient losses
Comparable profitability to conventional systems
Pressure remarks
Excessive reliance on chemical inputs
Soil erosion and biodiversity decline
Nutrient losses and climate stress on crops
Soil erosion and biodiversity decline
Nutrient losses and climate stress on crops
Part of a wider plan
No
Public consultation
Yes
Consultation activities
| Activity stage | Activity type | Comments |
|---|---|---|
| Other | Annual field days targeting agricultural stakeholders | Up to 300 farmers participated. Ongoing presentations to advisory circles in Germany and abroad. |
| Other | Project website and social media | maintained for dissemination |
Has contractual arrangements
No
Impacts and Monitoring
Monitoring System
Monitoring parameters
Around 24 field trials per year; between 10 and 40 exact trials annually depending on research focus
Master’s theses on nitrogen dynamics and water infiltration
On-farm measurements of evapotranspiration and CO₂ exchange using canopy chambers during main-crop season
Drone biomass and thermal imaging
Rain-simulator demonstrations for erosion and runoff understanding
Master’s theses on nitrogen dynamics and water infiltration
On-farm measurements of evapotranspiration and CO₂ exchange using canopy chambers during main-crop season
Drone biomass and thermal imaging
Rain-simulator demonstrations for erosion and runoff understanding
Maintenance
Maintenance requirements
Management research on controlling clover vertical growth when competition or genetic background caused excessive upward growth (tools or chemicals tested); no routine maintenance schedule reported.
Impact Assessment Methodology
Biophysical impact assessment method
Comparison of living-mulch vs conventional variants across three years and three locations with rotating crops
Field measurements of infiltration, ET and gas exchange, yield and quality (protein)
Economic comparison of inputs and contribution margin
Field measurements of infiltration, ET and gas exchange, yield and quality (protein)
Economic comparison of inputs and contribution margin
Socio-economic Impacts
Direct benefits
Yield gap vs conventional reduced from about 30–40 percent in year 1 (ecological farming baseline) to 10–14 percent in year 3
Contribution margin roughly comparable to conventional due to lower inputs of diesel, fertiliser and water
Knowledge exchange through large field days and international presentations
Contribution margin roughly comparable to conventional due to lower inputs of diesel, fertiliser and water
Knowledge exchange through large field days and international presentations
Biophysical impacts: Hydrology
Information on retained water
Higher infiltration rates measured in plots with established clover stand
Cooling of soil surface in mulched areas observed by drone thermal imaging
Less crop heat stress recorded with living mulch; net water savings despite evapotranspiration considerations
Improved water retention and erosion control reported
Cooling of soil surface in mulched areas observed by drone thermal imaging
Less crop heat stress recorded with living mulch; net water savings despite evapotranspiration considerations
Improved water retention and erosion control reported
Biophysical impacts: Biodiversity
Information on improved biodiversity
Enhanced soil health and biodiversity conservation reported with living mulch system (no quantitative indices provided).
Biophysical impacts: Water & Soil Quality
Information on water quality overall
Reduced nitrogen leaching in rainfall events in living-mulch treatment
Lower nutrient losses overall reported in nitrogen reduction experiment
Lower nutrient losses overall reported in nitrogen reduction experiment
Biophysical impacts: Others
Other biophysical impacts changes
Lower greenhouse gas emissions via reduced and more efficient use of production resources.
Lessons Learned
Key lessons
Evaluate at farm level; site-specific adaptation is essential
Weather variability and farm-specific approaches require flexibility
Continuous learning with scientific partners produced practical and statistically meaningful results
Weather variability and farm-specific approaches require flexibility
Continuous learning with scientific partners produced practical and statistically meaningful results
Drivers
| Driver type | Driver role | Comments |
|---|---|---|
| Legal obligations | Main driver | Need to meet European Green Deal goals and address soil degradation, erosion and high input dependency |
| Organisation committed to it | Secondary driver | Practitioner-led initiative supported by RDP Measure 16 cooperation |
Success factors
| Success factor type | Success factor role | Comments |
|---|---|---|
| Successful coordination between authorities | Main factor | Strong practitioner–researcher network and transparent communication, including sharing setbacks |
| Communication activities | Secondary factor | High-quality outreach via field days, demonstrations and bilingual website |
Cost effectiveness
Contribution margin roughly comparable to conventional due to reduced diesel, fertiliser and water inputs.
Transferability
Method is transferable but requires local adaptation; impacts in drier regions should be specifically studied before adoption.
Sources
Sources