Agronomy Research Expertise in Montpellier and Languedoc-Roussillon (South of France)

Agronomy : crops and cropping systems

Keywords :

The root system: in situ knowledge enables optimization of crop functioning

1. Ensuring top quality, high quantity production

1. Ensuring top quality, high quantity production

Root systems have many functions, e.g. supplying plants with water and nutrients, maintaining the soil structure and its organic status, and reducing erosion risks. The rhizosphere is also a unique ecological niche with intense soil biological activity. These features are especially important under tropical poor fragile soil conditions. The conventional measuring method whereby slices of soil under crops are extracted provides access to the root front and root biomass. However, in addition to its complexity, this method does not provide access to the spatial distribution of roots in the soil.

The developed method is based on mapping root intersections in a soil profile (RID). This facilitates study of the root distribution in the soil but does not indicate the root length per unit volume of soil (RLD), despite the fact that this variable is used to analyse and model the crop water supply. Validated semiempirical models were developed for maize, rainfed rice, sorghum and sugarcane to estimate RLD from RID. A specific software package was also developed to manage the many spatial data required for the method. It enables users to understand why cropping practices, such as tillage, fertilization and irrigation, have spatiotemporally variable effects. These field study methods and their results should help in designing and evaluating sustainable cropping systems in dry, nutrient- and carbon-poor environments. Studies are under way to link biomass and root lengths so as to be able to estimate biomass and its distribution via the root intersection mapping method.

Jean Louis Chopart,

Publication date: 30/05/2010




Update on 19/04/12


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