Tropical and Subtropical Agroecosystems最新文献

Background: Natural pasture is an essential source of livestock feed worldwide, particularly in Ethiopia. Though pastureland coverage and management practices are changing over time, studies are limited in addressing the status under the dynamics of smallholder management conditions. Objective: To evaluate natural pasture botanical composition, biomass yield, and nutritional value under different management and stages of harvesting in the central highlands of Ethiopia. Methodology: The pasture was harvested at three stages (pre-flowering, mid-flowering, and after full flowering) under different management (extensive, semi-intensive  where  urea was used as a fertilizer, and seasonal grazing). Quadrats of 0.25 m² were used for herbaceous species identification, biomass yield estimation and nutritive value analysis. Chemical composition of the samples were analyzed using Near-Infrared Reflectance Spectroscopy. Results: Thirty-one herbaceous species were identified (38.71% grasses, 19.35% legumes, 9.67% sedges, and 32.26% forbs), which belong to 11 families. The total biomass yield under semi-intensive management practice  at full maturity stage was greater than seasonally grazed and extensively managed pasture. The species richness, species evenness Shannon-Wiener diversity (H’ max) and maximum possible diversity (H’max) were similar (P>0.05) under all management practices. Natural pasture condition score was fair under seasonal grazing, while the score was excellent under extensive and semi-intensive management. Metabolizable energy (ME), and in vitro organic matter digestibility (IVOMD) were higher (P<0.5) under extensive management compared to the semi-intensive management. The pasture harvested at the pre-flowering stage had higher (P<0.05) CP content, IVOMD, and ME, but low neutral detergent fiber, acid detergent fiber and acid detergent lignin values. Implications: The findings provide new insights into improving the biomass yield and quality of the pasture in semi-intensive pastureland management, and harvesting after the full flowering stage. Conclusion: This study recommended semi-intensive management and harvesting after the full flowering stage for higher pasture biomass yield, pasture condition, and nutritional value in the highlands of Ethiopia. Further study is required to investigate the combined effects of fertilizer (organic, inorganic) application and other management on biomass yield and quality of natural pasture in similar and other areas in the highlands of Ethiopia. 

Introduction: Coffee is one of the leading tropical crops produced worldwide. Colombia ranks third in coffee production in the world. Microorganisms associated with coffee plants can have many biotechnological applications, such as plant growth promotion and biological control. Objective: To describe the bacteria present in the soil associated with coffee cultivation. This was done using a bulk sequencing or 16S rRNA metabarcoding approach. Methodology: Soil samples were collected to analyze their microbiome from three different departments of Colombia (Cauca, Risaralda and Magdalena). The plants were of different ages, and the crop management was different (conventional and organic). Subsequently, an analysis was carried out using Qiime2 to describe the communities associated with coffee cultivation and soil chemical properties. Results: Some important genera were identified, such as Janthinobacterium, Bacillus, Actinomadura and Actinoallomurus. These genera can be used as plant growth promoters, organic matter transformers, producers of antibiotics and metabolites with potential biotechnological applications. Implications: The study presented in this manuscript describes the communities associated with the soil in coffee cultivation. However, a much more complex approach could be through metagenomics, where the bacterial communities and the functions of; however, this vision is up to ten times higher in cost. Conclusion: Through the results obtained, it is concluded that the studies carried out through metabarcoding help to understand the composition of the microorganisms associated with coffee and, with this, try to elucidate the functions of the associated microorganisms.