Effect of Soil Collected under Eucalyptus camaldulensis Dehn on Peanut (Arachis hypogaea L.) Development and Soil Microbial Community Structure
Sire Diedhiou *
Department of Agroforestry, Assane Seck University, BP 523, Ziguinchor, Senegal.
Arfang O. K. Goudiaby
Department of Agroforestry, Assane Seck University, BP 523, Ziguinchor, Senegal.
Jean Bassene
Department of Agroforestry, Assane Seck University, BP 523, Ziguinchor, Senegal.
Yaya Diatta
Department of Agroforestry, Assane Seck University, BP 523, Ziguinchor, Senegal.
Ibrahima Ndoye
Department of Plant Biology, Cheikh Anta Diop University, Senegal and French Research Institute for Development (IRD), BP 1386, Dakar, Senegal.
Saliou Fall
French Research Institute for Development (IRD), BP 1386, Dakar, Senegal and Senegalese Institute of Agricultural Research, BP 3120, Dakar, Senegal.
*Author to whom correspondence should be addressed.
Abstract
Aims: The objective of this study was to determine the effect of soil sampled under E. camaldulensis on peanut development and microbial community.
Place and Duration of Study: Soil sampling at the 0-10 cm horizon was conducted at different distances: 1.5 m, 3 m, 4.5 m, 6 m and 30 m from 3 randomly selected E. camaldulensis plants in four sites: Karamba, Nicia, Rokout and Dioncome.
Methodology: A two-factor randomized complete block design was set up in a greenhouse experiment and parameters such as chlorophyll content, acetylene reducing activity, mycorrhization rate, number of nodules, mass of dry matter and microbial community structure were studied.
Results: No significant difference was noted among the parameters regardless of the sampling distance for the Karamba, Nicia and Dioncome sites (P>0.05). In the case of Rokout site, however, the chlorophyll content measured at 4.5 m was significantly different from the chlorophyll content measured at 1.5 m from the tree. For aboveground dry biomass, no significant difference was noted regardless of sampling distance at Karamba and Rokout sites except for samples collected at 4.5 m (Pa≤0, 045; Pc≤0.029). No significant difference was also noted for root biomass regardless of sampling distance at the Karamba, Rokout, and Dioncome sites (P>0.05). However, at Nicia, the biomass of the control treatment was significantly higher compared to others (P=0.021). Nodulation did not vary according to sampling distance (P>0.05). The amount of nitrogen fixed is higher at 6 m from Eucalyptus compared to other distances at the Karamba and Nicia sites (P<0.02). In contrast, at Boucotte it is higher at 1.5 m from the tree (P<0.03). Mycorrhization intensity was significantly higher at 6 m and 30 m from the tree compared to other distances.
Conclusion: Microbial community structure differed between soil collected under and outside of the canopy of E. camaldulensis.
Keywords: Eucalyptus camaldulensis, peanut, microbial community