Land-use change and management practices are normally enacted to manipulate environments to improve conditions that relate to production, remediation, and accommodation. However, their effect on the soil microbial community and their subsequent influence on soil function is still difficult to quantify. Recent applications of molecular techniques to soil biology, especially the use of 16S rRNA, are helping to bridge this gap. In this study, the influence of three land-use systems within a demonstration farm were evaluated with a view to further understand how these practices may impact observed soil bacterial communities. Replicate soil samples collected from the three land-use systems (grazed pine forest, cultivated crop, and grazed pasture) on a single soil type. High throughput 16S rRNA gene pyrosequencing was used to generate sequence datasets. The different land use systems showed distinction in the structure of their bacterial communities with respect to the differences detected in cluster analysis as well as diversity indices. Specific taxa, particularly Actinobacteria, Acidobacteria, and classes of Proteobacteria, showed significant shifts across the land-use strata. Families belonging to these taxa broke with notions of copio- and oligotrphy at the class level, as many of the less abundant groups of families of Actinobacteria showed a propensity for soil environments with reduced carbon/nutrient availability. Orders Actinomycetales and Solirubrobacterales showed their highest abundance in the heavily disturbed cultivated system despite the lowest soil organic carbon (SOC) values across the site. Selected soil properties ([SOC], total nitrogen [TN], soil texture, phosphodiesterase [PD], alkaline phosphatase [APA], acid phosphatase [ACP] activity, and pH) also differed significantly across land-use regimes, with SOM, PD, and pH showing variation consistent with shifts in community structure and composition. These results suggest that use of pyrosequencing along with traditional analysis of soil physiochemical properties may provide insight into the ecology of descending taxonomic groups in bacterial communities.

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The Sustainable Technology for Orange and Purple Sweetpotatoes (STOPS) project, led by researchers from Tuskegee University, USA, identified gaps in the value chain from production, processing, product development to consumption of sweet potato, aimed at addressing vitamin A deficiency (VAD) and improving the health and nutritional status of vulnerable populations in rural communities in Ghana. The orange sweet potato (OSP) could be an inexpensive, year-round, rich source of β-carotene, a precursor of vitamin A. The anthocyanins that account for the purple pigmentation in the purple variety are powerful antioxidants with good bioavailability to be easily absorbed by the body. The STOPS project promotes the utilization of both varieties into value-added products from the root including flour, yogurt, and bread. Sweet potato-based bread, TUO vitabread, prepared from a composited wheat flour and OSP puree at a ratio of 2.5:1 ("as-is" basis) was compared with traditional wheat (white) bread on the Ghanaian market in compositional and sensory analyses. The proximate composition (moisture, protein, fat, ash and carbohydrate by difference) and energy content were not statistically different (P>0.05), although TUO vitabread contains 18% more moisture than the white bread. The β-carotene and lutein concentrations in the OSP-based bread were approximately 6-fold higher (P=0.01). The TUO vitabread could meet 17% of the daily adequate intake of vitamin A for a 1-to 3-year-old child consuming about 50 g of the bread, but only 3% from the white bread. Consumer preference assessment of 50 undergraduate students showed a high preference for the OSP puree-based bread but further work on extension of shelf-life under ambient conditions is warranted. Thus, the inclusion of OSP in the traditional diet can be an inexpensive and year-round source of dietary β-carotene to complement the vitamin A supplementation programme to reduce VAD in children.

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Waste resulting from industrial poultry production systems is becoming an increasingly significant environmental problem in the US, threatening both soil and water quality. The goal of this study was to assess the spatial variability and interactions of selected soil properties (physical, chemical, and biochemical), viz., particle size, pH, enzymatic activity, Soil Organic Carbon (SOC), and Total Nitrogen (TN), across an agricultural landscape used for industrial poultry production. The measured soil properties were separated according to biochemical constituents and soil texture based on the first two principal components, accounting for approximately 60% of the variability across the site. These principal components were then used to generate soil surface maps, indicating areas of possible catalytic activity. Surface maps showed possible increases in biochemical activity around areas of stored poultry litter, suggesting the utility of these methods in determining changes to soil management.