Efficiency of Bio-Fertilizing as One of the Natural Alternatives to Improve the Growth of Khaya senegalensis and Swietenia mahagoni Trees and for Sustainability

A field experiment was carried out at Ismailia Research Station, Ismailia Governorate from 2020-2022 to improve the growth of Khaya senegalensis and Swietenia mahagoni by using a combination of mineral fertilizer (NPK) and biological fertilizer (Azotobacter chroococcum, Bacillus megatherium, and Bacillus circulant) as recommended dose under new sandy soils conditions. Split plot designed with four treatments (Control, (50% Mineral fertilizer (M.) + 50% Biological fertilizer (Bio.)), 100% M. and 100% Bio.) of each species. Vegetative growth, leaf area, tree biomass, stored carbon, basal area, tree volume, and in the soil both of microbial account and mineral content were determined. The experimental results showed no significant differences between studied species among the most studied parameters except for Khaya senegalensis which gave the highest significant difference in root biomass and below-stored carbon than Swietenia mahagoni. Evidently, the highest significant growth parameters were 100% mineral fertilizer followed by (50% M. + 50% Bio.) as compared with control. No significant difference between 100% M. and (50% M. + 50% Bio.) of shoot dry biomass (15.19 and 12.02 kg, respectively) and above-stored carbon (0.28 and 0.22 Mt, respectively). Microbial account and mineral content in soil were improved after cultivation of tree species compared to before planting and control, especially with 50% mineral fertilizer and 50% bio-fertilizer treatment. In conclusion, a treatment containing 50% mineral fertilizer and 50% bio-fertilizer has led to the ideal Khaya senegalensis and Swietenia mahagoni growth in sandy soil for cheaper and sustainable.

Characteristics and Diversity of Cyanobacteria in Periphyton from Lentic Tropical Ecosystem, Brazil

This study aimed to perform the taxonomic survey of the species of periphytic Cyanobacteria in a lentic tropical environment, seeking to contribute to the knowledge on biodiversity and their distribution. This study was conducted at the Samambaia Reservoir, which is located at Federal University of Goiás, Goiania, Central West region of Brazil. In general, the water of the Samambaia Reservoir is characterized as more turbid and the increased biochemical oxygen demand as well as a higher concentration of coliforms in the rainy season. Twenty six samples were collected, ten in the dry season (09/2010 and 11/2010;07/2012) and ten in the rainy season (01/2011 and 03/2011;01/2013). Periphyton was collected from stems of aquatic plants (Cyperaceae), which were in the marginal area of the reservoir. With the floristic survey, 38 taxa of Cyanobacteria were identified in periphyton of the Samambaia Reservoir. Phormidium (family Phormidiaceae) and Aphanocapsa (Merismopediaceae) are among genera with the highest species richness. Regarding morphological types, many species of filamentous cyanobacteria were identified, followed by colonial taxa. In relation to the frequency of occurrence and the seasonal period, 14 taxa were classified in the rare category, 12 in common category and 12 in constant category. Regarding the seasonal period, Cyanophyceae were the greatest wealth in the rainy season (97.4%).