Long term trials in SOILCOM extensive source of information

27 July 2021 - Published by Hanne Lakkenborg Kristensen

Written by Esther Hessel. The partners in SOILCOM are already some years active in long term trials with compost. Also within this project they will follow these long term trials. And will bring together the different experiences and results.

The partners is SOILCOM are already some years active in long term trials with compost. Also within SOILCOM they will follow these long term trials. And will bring together the different experiences and results.

Long-term application of compost will improve the soil physical and biological quality. The extent of the effects may vary based on soil type and climatic differences. A common sampling scheme was developed to measure soil chemical, biological and physical parameters in 5 long-term trials with compost. The trials are located in Belgium (ILVO, PSKW, PCS), Scotland (James Hutton Institute) and Denmark (Aarhus University) and have been running for 4-17 years.

In the table the list of trials, when they started and which crops are grown in 2021.

Location	Since	Crop in 2021
ILVO, Belgium	2010	Fodderbeet
PSKW, Belgium	2006	Beetroot
PCS, Belgium	2012	Hornbeam
James Hutton Institute	2004	Cereals
Arhus University, Department of foodscience	2018	Beetroot

In Soilcom the partners want to test the following hypotheses.

Long-term compost application will:

• Improve soil physical quality (structure and water holding capacity)

• Increase microbial life (hot water extractable C and potential N mineralization)

• Increase soil fertility (nutrient content)

• Plant growth (seedling emergence, yield)

Currently, soil nutrient analyses and soil bulk density have been measured in a majority of trials. Crop yield parameters will be measured in the autumn. The results from the common sampling will be valuable to draw conclusions about the effect of compost in a variety of crops, soil types and climates.

Centre for sustainable cropping James Hutton Institute

At the James Hutton’s Centre for sustainable cropping long term trials since 2010 and 2004 are followed. Also application of composts compared with a no-compost treatment is part of the trial. In the first trial, 10 tons of compost per hectare per year was applied. In the second trial compost together with slurry was applied. With different compost applications for 4 years, before a standard of 35 tons of compost per hectare per year since 2008.

JHI routinely collect data on biomass, crop development, seedbanks and soil chemistry.