A method of appraising the root systems of grassland swards
Paru en 1964 dans Fourrages n°19 (page 91 à 94)
Auteurs : Deffontaines J.P.
This method is drawn from the observation of the cultivation profile and enables the setting up of a rapid diagnostic on the root systems of a grassland sward. The technique consists in counting the roots in a soil profile that has been adequately prepared ; this counting can be done on photographic records. On the projected pictures of the colour slides, the roots are numbered that intersect horizontal segments of definite length drawn at different levels on the profile: 4 in., 8 in., 10 in.
On leys situated in the middle of the Millevaches plateau, countings were carried out according to this method. A significant correlation r =.35 was found (.38 is the limit of significance for P = .05) between yield and the ratio <s> of total number of intersections at the three levels to a factor of roots distribution in the profile : this factor being itself the ratio of the nmber of intersections at the 4 in. level to that at the 8 in. level. In the present case, < s> may thus serve as a yield indicator.