Soil microorganisms play fundamental roles in the maintenance of biological fertility in agricultural soils, delivering important ecosystem services, such as the completion of biogeochemical cycles and the improvement of soil structure and plant nutrition. The use of cover crops represents a sustainable soil management practice able to maintain crop productivity and to enhance the functional activities of beneficial soil microbiota. This work investigated the impact of cover crops on the biodiversity of soil microbial communities, compared with natural grass cover, in a Mediterranean olive orchard. Soil samples harvested in two successive years were analysed by PCR-Denaturing Gradient Gel Electrophoresis of partial 16S rRNA gene and sequencing the dominant bacterial and fungal taxa. Cluster analysis, non-metric multidimensional scaling (NMDS) and ANOSIM revealed significant differences in the composition of bacterial communities between the two sampling times (R=0.7037 e p=0.0198) and between natural grass cover vs. cover crops (R=0.61111e p=0.0301). The diversity of soil bacterial communities of the two treatments was confirmed also by biodiversity indices: Shannon index significantly increased (P=0.0008) in samples from the cover crops trial, compared with the natural grass cover, as well as the indices Hill1 (P=0.004) and Hill2 (P=0.0006). Proteobacteria and Acidobacteria were the dominant phyla in all samples. Also for fungal communities, ANOSIM test showed significant differences in the composition of fungal communities between both the two sampling times (R=0.51852 and p=0.013) and the two treatments (R=0.61111 and p=0.01). Results obtained from NMDS showed that the composition of fungal communities diverged mainly on the basis of orchard soil management and secondly on sampling time. Present results show that the use of cover crops in olive orchard management is a better option not only in comparison to tillage, but also to natural grass cover, to maintain and improve soil microbiological diversity and fertility.
Diversity and composition of soil microbial communities in olive orchards as affected by cover crops, season and natural grass cover
Arianna GrassiPrimo
;Irene PagliaraniSecondo
;Caterina Cristani;Manuela Giovannetti;Alessandra Turrini;Monica Agnolucci
Ultimo
2023-01-01
Abstract
Soil microorganisms play fundamental roles in the maintenance of biological fertility in agricultural soils, delivering important ecosystem services, such as the completion of biogeochemical cycles and the improvement of soil structure and plant nutrition. The use of cover crops represents a sustainable soil management practice able to maintain crop productivity and to enhance the functional activities of beneficial soil microbiota. This work investigated the impact of cover crops on the biodiversity of soil microbial communities, compared with natural grass cover, in a Mediterranean olive orchard. Soil samples harvested in two successive years were analysed by PCR-Denaturing Gradient Gel Electrophoresis of partial 16S rRNA gene and sequencing the dominant bacterial and fungal taxa. Cluster analysis, non-metric multidimensional scaling (NMDS) and ANOSIM revealed significant differences in the composition of bacterial communities between the two sampling times (R=0.7037 e p=0.0198) and between natural grass cover vs. cover crops (R=0.61111e p=0.0301). The diversity of soil bacterial communities of the two treatments was confirmed also by biodiversity indices: Shannon index significantly increased (P=0.0008) in samples from the cover crops trial, compared with the natural grass cover, as well as the indices Hill1 (P=0.004) and Hill2 (P=0.0006). Proteobacteria and Acidobacteria were the dominant phyla in all samples. Also for fungal communities, ANOSIM test showed significant differences in the composition of fungal communities between both the two sampling times (R=0.51852 and p=0.013) and the two treatments (R=0.61111 and p=0.01). Results obtained from NMDS showed that the composition of fungal communities diverged mainly on the basis of orchard soil management and secondly on sampling time. Present results show that the use of cover crops in olive orchard management is a better option not only in comparison to tillage, but also to natural grass cover, to maintain and improve soil microbiological diversity and fertility.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
