Grass complementary root traits of ryegrass (Lolium perenne L.) and tall fescue (Festuca aurundinacea Schreb.) improve yields in a low P soil.
Résumé
Phosphorus (P) is one of the main nutrients used by grasses to reach high yields. However, P rocks
are limited and overfertilization can lead to serious environmental damage. This motivates the
introduction of smart combinations of grasses with the ability of accessing less soluble P pools in
soils. In this field experiment, we cultivated Lolium perenne L. and Festuca arundinacea Schreb.
in monocultures and in combination. Moreover, we also cultivated a combination of the latter
species with a tetraploid variety of Lolium and Phleum pratense L. Plants were grown in an
unfertilized low P sandy soil with and without P fertilization for two growing seasons. We
measured biomass production, root traits, nutrient uptake, microbial biomass and enzymatic
activities at the end of the experiment. We observed that, in the unfertilized plots, the combination
of ryegrass and tall fescue generated the highest cumulative yields, relative total yield (RYT) and
P nutrition index (PNI). These results can be explained by the complementarity found in root traits
between Festuca and Lolium. Fescue showed higher root biomass (98.14 ± 18.6 g m-2) at deeper
soil layers compared to ryegrass (43.85 ± 6.31 g m-2). On the other hand, ryegrass had finer roots
than fescue both at top soil and bottom layers. The combination of 4 different grasses did not result
in higher yields, however, soil C, microbial P biomass, alkaline phosphatase and β-glucosidase
were increased in the unfertilized plots. Our results show that, at low P soils, combinations of grass
species with contrasting root traits could lead to significantly higher yields than monocultures.
Fichier principal
Combination of english ryegrass and tall fescue improve_2.pdf (936.91 Ko)
Télécharger le fichier
Origine | Fichiers produits par l'(les) auteur(s) |
---|