Effect of seed-beds on the cultivation of Radicchio (Cichorium intybus L., Rubifolium group)

The use of raised beds (i.e., ridged soil layers) to cultivate vegetables can improve soil quality, crop performance, water use and even reduce soil erosion. Although those advantages are well known and documented in the literature for many vegetable species, Radicchio, a particular variety of chicory, is usually cultivated in flat seed-beds and, therefore, the achievable benefits of raised beds for this vegetable are not yet known. The possibility to grow plants of Radicchio on raised beds is here evaluated by comparing the most important yield performances indicators deriving from the adoption of this practice (grown plants percentage, average head weight, marketable yields, and net incomes) with the same indicators recorded with a conventional practice making use of flat seed-beds. The results evidenced that raised beds for Radicchio had a statistically significant effect on the average head weight (+55.45 g plant-1 with 15-cm beds) with significant increases of field yields (up to +30.6%) and net incomes (up to +29.7%) on the trials with flat seed-beds. The experiment showed that the production of chicory can take an economical advantage from the use of raised seed-beds and, therefore, this system is preferable to the traditional cultivation practice

Removal and Reuse of Phosphorus as a Fertilizer from CAFO Runoff

Eutrophication is the process in which nutrient saturated waters promote algal blooms on the surface of the water. This limits the amount of dissolved oxygen content in the water, effectively limiting the range of species that can survive in a body of water. Concentrated animal feeding operations (CAFO) can contribute to this issue. The animals in a CAFO produce large amounts of nutrient-rich waste streams that can enter natural waterways if not properly managed and increase the problem of eutrophication. The ability to treat these waste streams and recover the excess nutrients would allow for not only the reduction of nutrient leaching and runoff but would help create sustainable phosphorus practice. Phosphorus is vital in terms of food production, and there is no replacement for phosphorus for plants or humans. As the population continues to increase, food demand will as well. This means that at any point that phosphorus can be recovered, it should be. To recover phosphorus effectively from waste water sources, reverse osmosis, anion exchange, or adsorption are all viable options. Woo Pig Pooie researched these options for recovering phosphorus, and adsorption was found to be the most promising from standpoints of low maintenance and cost effectiveness. Multiple adsorption materials were ranked based on appropriate performance of cost, particle size, adsorption qualities, and the effects of application of the material. Water treatment residuals, WTR (i.e. spent alum from a drinking water treatment plant), was determined to be the most effective adsorbent. WTR, a waste product, is 80% water as it exits the water treatment plant. It must be pelletized and dried before use as an adsorbent. Pelletized and dried WTR was utilized in a full-scale facility treating 62 GPM of feed using two 11,000 gallons packed columns with associated equipment. If the cost of pelletizing and drying the WTR is included, an alternative strategy for implementation on individual farms is for several farmers to form a cooperative, which would allow the minimization of the $1,460,000 fixed capital cost and the$504,000 cost of manufacturing of the drying pelletizing facility. This would allow for the maximum amount of WTR to be treated increasing the revenue of the operation to $731,500. The cooperative would have an operation of 10 years with a net present value of$5,000. Experimental results using WTR packed columns have shown non-detectable levels of phosphorus in the effluent. The produced phosphorus saturated WTR could be land applied to reduce the level of nutrients in runoff from fields, making a safer agriculture operation

Designing Environmental Policy: Lessons from the Regulation of Mercury Emissions

In its waning days, the Clinton administration decided that it was appropriate to regulate mercury emissions from power plants. The incoming Bush administration had to decide how best to regulate these emissions. The Bush administration offered two approaches for regulating mercury emissions from power plants. The first was to establish uniform emission rates across utilities, as mandated by the 1990 Amendments. The second was to establish a cap on mercury emissions while allowing emissions trading in order to reduce the cost of achieving the goal. This paper presents the first cost-benefit analysis of this issue that takes account of IQ benefits. We find that the benefits of the mercury regulation are likely to fall short of the cost. This assessment is based on a number of assumptions that are highly uncertain. The finding of negative net benefits is robust to many, though not all, reasonable variations in the model assumptions. We also find that the emissions trading proposal is roughly $15 billion less expensive than the command-and-control proposal.

Removal and Reuse of Phosphorus as a Fertilizer from CAFO Runoff

Eutrophication is the process in which nutrient saturated waters promote algal blooms on the surface of the water. This limits the amount of dissolved oxygen content in the water, effectively limiting the range of species that can survive in a body of water. Concentrated animal feeding operations (CAFO) can contribute to this issue. The animals in a CAFO produce large amounts of nutrient-rich waste streams that can enter natural waterways if not properly managed and increase the problem of eutrophication. The ability to treat these waste streams and recover the excess nutrients would allow for not only the reduction of nutrient leaching and runoff but would help create sustainable phosphorus practice. Phosphorus is vital in terms of food production, and there is no replacement for phosphorus for plants or humans. As the population continues to increase, food demand will as well. This means that at any point that phosphorus can be recovered, it should be. To recover phosphorus effectively from waste water sources, reverse osmosis, anion exchange, or adsorption are all viable options. Woo Pig Pooie researched these options for recovering phosphorus, and adsorption was found to be the most promising from standpoints of low maintenance and cost effectiveness. Multiple adsorption materials were ranked based on appropriate performance of cost, particle size, adsorption qualities, and the effects of application of the material. Water treatment residuals, WTR (i.e. spent alum from a drinking water treatment plant), was determined to be the most effective adsorbent. WTR, a waste product, is 80% water as it exits the water treatment plant. It must be pelletized and dried before use as an adsorbent. Pelletized and dried WTR was utilized in a full-scale facility treating 62 GPM of feed using two 11,000 gallons packed columns with associated equipment. If the cost of pelletizing and drying the WTR is included, an alternative strategy for implementation on individual farms is for several farmers to form a cooperative, which would allow the minimization of the $1,460,000 fixed capital cost and the$504,000 cost of manufacturing of the drying pelletizing facility. This would allow for the maximum amount of WTR to be treated increasing the revenue of the operation to $731,500. The cooperative would have an operation of 10 years with a net present value of$5,000. Experimental results using WTR packed columns have shown non-detectable levels of phosphorus in the effluent. The produced phosphorus saturated WTR could be land applied to reduce the level of nutrients in runoff from fields, making a safer agriculture operation

Spontaneous emergence of spatial patterns ina a predator-prey model

We present studies for an individual based model of three interacting populations whose individuals are mobile in a 2D-lattice. We focus on the pattern formation in the spatial distributions of the populations. Also relevant is the relationship between pattern formation and features of the populations' time series. Our model displays travelling waves solutions, clustering and uniform distributions, all related to the parameters values. We also observed that the regeneration rate, the parameter associated to the primary level of trophic chain, the plants, regulated the presence of predators, as well as the type of spatial configuration.Comment: 17 pages and 15 figure

Strategic Human Capital Management: NRC Could Better Manage the Size and Composition of Its Workforce by Further Incorporating Leading Practices

[Excerpt] After the passage of the Energy Policy Act of 2005, which included tax incentives for nuclear energy, NRC significantly expanded its workforce to meet the demands of an anticipated increase in workload that ultimately did not occur. More recently, a forecast for reduced growth in the nuclear industry prompted NRC to develop plans for changing its structure and workforce to better respond to changes in the nuclear industry. Strategic human capital planning is one of several actions the agency is taking. The explanatory statement accompanying the Consolidated Appropriations Act for fiscal year 2016 included a provision for GAO to report on NRC’s workforce management. GAO examined NRC’s strategic human capital management efforts and the extent to which these efforts incorporate leading practices. GAO reviewed NRC’s strategic workforce plan and other related documents and interviewed knowledgeable NRC officials

Global supply chains of high value low volume products

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A review on the complementarity of renewable energy sources: concept, metrics, application and future research directions

It is expected, and regionally observed, that energy demand will soon be covered by a widespread deployment of renewable energy sources. However, the weather and climate driven energy sources are characterized by a significant spatial and temporal variability. One of the commonly mentioned solutions to overcome the mismatch between demand and supply provided by renewable generation is a hybridization of two or more energy sources in a single power station (like wind-solar, solar-hydro or solar-wind-hydro). The operation of hybrid energy sources is based on the complementary nature of renewable sources. Considering the growing importance of such systems and increasing number of research activities in this area this paper presents a comprehensive review of studies which investigated, analyzed, quantified and utilized the effect of temporal, spatial and spatio-temporal complementarity between renewable energy sources. The review starts with a brief overview of available research papers, formulates detailed definition of major concepts, summarizes current research directions and ends with prospective future research activities. The review provides a chronological and spatial information with regard to the studies on the complementarity concept.Comment: 34 pages 7 figures 3 table

Historical contingency in species interactions: towards niche-based predictions.

The way species affect one another in ecological communities often depends on the order of species arrival. The magnitude of such historical contingency, known as priority effects, varies across species and environments, but this variation has proven difficult to predict, presenting a major challenge in understanding species interactions and consequences for community structure and function. Here, we argue that improved predictions can be achieved by decomposing species' niches into three components: overlap, impact and requirement. Based on classic theories of community assembly, three hypotheses that emphasise related, but distinct influences of the niche components are proposed: priority effects are stronger among species with higher resource use overlap; species that impact the environment to a greater extent exert stronger priority effects; and species whose growth rate is more sensitive to changes in the environment experience stronger priority effects. Using nectar-inhabiting microorganisms as a model system, we present evidence that these hypotheses complement the conventional hypothesis that focuses on the role of environmental harshness, and show that niches can be twice as predictive when separated into components. Taken together, our hypotheses provide a basis for developing a general framework within which the magnitude of historical contingency in species interactions can be predicted