16 October
31 December 2012

Effet à long terme des apports d’amendements organiques et calciques et des fertilisants phospho-potassiques

Long term study on organic and calcic amendments and on P and K fertilizers


Organic amendments and P-K fertilizers have an influence on soil fertility, but long term experiments are needed to evaluate this influence. Only a public research organism can invest in such experiment which initiated in 1959 has allowed to make practical recommendations for the farmer. Moreover this project is an essential reference for the study of sustainability of agricultural systems.


This project has two main objectives: 1. to compare methods and types of organic matter inputs (crop residues, green manure, animal husbandry effluents, no input) with regards to crop yields and to the evolution of soil fertility. A particular attention is taken to humus content and structural stability of the soil and the nitrogen dynamic 2. to compare three levels of mineral P K fertilizers input (level 0, level representing theoretical crop export, 2 X this level) with regards to crop yields and to the evolution of P-K soil reserve, which is regularly investigated in more fundamental research.

Description of tasks

Realisation of thea gronomic trials (8 ha of arable crops)

Collect of soils and crops samples

Analyze of these samples in laboratory.

Expected results

To move farm towards economic and environmentally sustainable solutions with regards to organic matter and PK fertilizer management

Results obtained

As a result of the project, it must be underlined that more than the doses of organic amendment applied, the frequency of application and the management during the crop rotation are important for the soil fertility. With regards to P and K fertilization, a recommendation based on a balance level is sufficient to maintain available P-K reserves of the soil.


Experimental works

Chemical analysis such as determination of K, Ca and Mg contents of soil and plant extract.


There are very few long term experiments conducted in European countries and the CRA-W is often requested to exchange informations or to provide samples. These trials were integrated in European networks (COST 814 et 832). Regularly, belgian faculties of agronomy realize studies on this material.

CRAW off coordinator

DESTAIN Jean-Pierre (Inspecteur général scientifique) Rue du Bordia, 4 B-5030 Gembloux Téléphone direct :62 50 17 Téléphone département :+ 32 (0) 81 / 62.50.00 Fax département :+ 32 (0) 81 / 61.41.52 E-mail :destain@cra.wallonie.be


  • CRA-W - Walloon Agricultural Research Centre