Crop response to fertilizers as an index of soil health

Marc-Olivier Gasser, researcher

Marc-Olivier Gasser

Researcher, agr., Ph.D.

418 643-2380
ext 650

Contact Marc-Olivier Gasser
Catherine Bossé, Project Manager – Pedology

Catherine Bossé

Project Manager – Pedology, agr.

418 643-2380
ext 405

Contact Catherine Bossé
Christine Landry, researcher

Christine Landry

Researcher, agr., Ph.D.

418 643-2380
ext 640

Contact Christine Landry


The yield potential of crops is limited by the climate as well as by the intrinsic nature of the soils, their level of land improvement and their state of health. The importance of soil health is sometimes underestimated by agricultural companies, which can lead to fertilization being carried out beyond the needs of crops or fertilization grids. Cultivation practices and fertilization normally improve crop yield, but fertilization does not always affect crop yield according to the predicted recommendation patterns. Some fertilization trials also show that crops do not respond to fertilizer inputs according to the prescribed average recommendations. It can be hypothesized that the physical condition of the soil and the microbial and biological activity that depend on it influence the response of crops to fertilizers. In fact, the response of crops to nitrogen fertilizers has been linked to indicators of nitrogen sufficiency in the soil or the plant, as well as to the biophysical properties of the soil that make this nitrogen available. Conversely, it seems important to verify whether the response of crops to fertilizers can serve as an indicator for detecting soil health problems and for raising awareness among producers to assess the state of health or condition of their soils.


The project should investigate how the health or physical condition of the soil and its profile influence the response of crops to nitrogen fertilizers, when routine soil tests indicate no problems, in order to contribute to the development of an indicator soil health based on crop response to fertilizers. It also aims to demonstrate to agricultural businesses:

  1. that the state of soil health, more particularly the physical condition of the crop profile, can affect biological activity in the soil, the availability of nutrients, the need for additional fertilizers and ultimately the response of crops to fertilizers;
  2. that the productivity potential of a field is closely linked to the soil, its physical condition and the quality of the crop profile;
  3. that an improvement in the physical condition of the crop profile could translate into a reduction in the quantities of fertilizer to be applied and savings in inputs.

From 2019 to 2023

Project duration

Field crops

Activity areas

Soil health, Soil Information, Water protection



12 agri-environment advice clubs
Belisle Agricultural Analysis Laboratory

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