Project

Investigating root trait plasticity and weed suppression in cereal-legume intercropping systems

Intercropping, the simultaneous cultivation of multiple crop species on the same land, offers several advantages over sole crop stands, including enhanced weed suppression. Aboveground plant plasticity can explain the mechanisms of enhanced weed suppression to a certain degree. However, root systems also react plastically to their environment, and express a different phenotype in intercrops. It is unclear to what extent root systems in an intercrop adapt to the presence of the other species and the presence of weeds, and how much this contributes to enhanced weed suppression. To shed light on this phenomenon, this project aims to investigate root traits of triticale and faba bean plants in weed infested and weed free field plots, as well as their impact on weed biomass.

Project description

Intercropping is the agricultural practice where two or more crop species are cultivated simultaneously within a single season on the same area of land. One of the potential benefits of intercropping is improved weed suppression compared to the average of the sole crops. This effect has been investigated in the field looking at above-ground system and plant variables. Intercropped plants adapt their above-ground architecture to their environment, causing the more competitive component species to take more than its fair share of weed suppression. Indeed, in a cereal-legume intercrop system, the cereal crop contributes more to weed suppression than expected from its sole crop stand, indicating the presence of a benefit. However, it is unclear how much below-ground plant plasticity contributes to the phenomenon of enhanced weed suppression. Although we know that cereal-legume intercrop systems have different root systems than their sole crops, it is unclear how they adapt to the presence of weeds, and how much this affects weed biomass in these systems.

A field experiment will be done that involves different treatment groups, each
containing triticale plants, faba bean plants, or a combination of both.
Additionally, the treatments will vary in terms of weed presence (weed-free or
weed-infested). Root traits of the crop species will be examined. Furthermore,
the weed biomass of the weed-infested plots will be measured. Through this
experiment, we aim to unravel the below-ground mechanisms involved in weed
suppression and identify the root plasticity traits that contribute to this
phenomenon.

Objectives and methods

The aim of the experiment is to assess the differences in root traits between intercrops and sole crops of triticale and faba plants in weed-free and weed-infested field plots. Furthermore, we will investigate the effects of these different
treatments on weed biomass. Various root architectural traits will be measured.
Optionally, root biomass proportion measurements will be conducted at various distances from the rows through proportional DNA analysis. The student(s) will carry main responsibility for the experiment. Within this topic it is possible for the student(s) to develop their own research ideas.

Required skills

Basic statistics. Useful but not required: experience with field and/or root experiments, R.

Types of research/work

Field experiment (setting up and taking care of the experiment, collecting samples), lab work at Unifarm (root washing, taking measurements), optionally lab work at cell biology group (DNA analysis), data analysis.