935 resultados para Cropping systems and livestock
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Many forested areas have been converted to intensive agricultural use to satisfy food, fiber, and forage production for a growing world population. There is great interest in evaluating forest conversion to cultivated land because this conversion adversely affects several soil properties. We examined soil microbial, physical, and chemical properties in an Oxisol (Latossolo Vermelho distrófico) of southern Brazil 24 years after forest conversion to a perennial crop with coffee or annual grain crops (maize and soybeans) in conventional tillage or no-tillage. One goal was to determine which soil quality parameters seemed most sensitive to change. A second goal was to test the hypothesis that no-tillage optimized preservation of soil quality indicators in annual cropping systems on converted land. Land use significantly affected microbial biomass and its activity, C and N mineralization, and aggregate stability by depth. Cultivated sites had lower microbial biomass and mineralizable C and N than a forest used as control. The forest and no-tillage sites had higher microbial biomass and mineralizable C and N than the conventional tillage site, and the metabolic quotient was 65 and 43 % lower, respectively. Multivariate analysis of soil microbial properties showed a clear separation among treatments, displaying a gradient from conventional tillage to forest. Although the soil at the coffee site was less disturbed and had a high organic C content, the microbial activity was low, probably due to greater soil acidity and Al toxicity. Under annual cropping, microbial activity in no-tillage was double that of the conventional tillage management. The greater microbial activity in forest and no-tillage sites may be attributed, at least partially, to lower soil disturbance. Reducing soil disturbance is important for soil C sequestration and microbial activity, although control of soil pH and Al toxicity are also essential to maintain the soil microbial activity high.
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This report was developed to provide summary information to allow state agency staff, practitioners and juvenile justice system officials to access specific sections of Iowa’s Three Year Plan. It includes the “Service Network” section of Iowa’s 2006 Juvenile Justice and Delinquency Prevention Act formula grant Three-Year Plan. The complete Three Year Plan serves as Iowa’s application for Juvenile Justice and Delinquency Prevention Act formula grant funding. The information included in this report overviews some of the systems and services that relate to Iowa’s delinquency and CINA systems. The systems and services discussed include substance abuse , mental health, alternative or special education, and job training.
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The effect of intercropping on plant water status, gas exchange and productivity of maize (Zea mays L.) cv. Centralmex, and cowpea (Vigna unguiculata L. (Walp)) cv. Pitiuba were evaluated under semi-arid conditions at the Embrapa-Centro de Pesquisa Agropecuária do Trópico Semi-Árido (CPATSA) at Petrolina, PE, Brazil. The treatments were: maize and cowpea as sole crops, at a population of 40,000 plants ha-1, and intercropped at a population of 20,000 plants ha-1. The results obtained in this paper appear to be related to the degree of competition experienced by the components, mainly for water and light. Maize intercropped had higher values of leaf water potential, stomatal conductance, transpiration and photosynthesis than as sole crop. Intercropped cowpea had higher values of leaf water potential but lower stomatal conductance, transpiration and photosynthesis than sole cowpea. Maize productivity increased 18% in relation to sole crop whereas a 5% decrease was observed with cowpea. Despite these facts the Land Equivalent Ratio obtained was 1.13 indicating intercropping advantage over the sole system. The higher partial Land Equivalent Ratio observed for maize suggests that this specie was the main component influencing the final productivity of the intercropping system studied.
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The federal government mandated that all non-federal public safety license holders on the frequencies ranging from 150 to 512 megahertz reduce their operating bandwidth from 25 kilohertz to 12.5 kilohertz. Narrowband channels must update their operating licenses by January 1, 2013. Failure to do so will result in the loss of communication capabilities and fines. This issue review analyzes the impact to state agencies of the federal mandate requiring all two-way radio systems and some paging networks, including those used by public-safety agencies, to meet the new narrowband requirements by January 1, 2013. This issue review does not address the impact to local communications systems.
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The dramatic rise in fuel prices and growing environmental concerns are pressing freight transportation companies to pursue new systems and methods to improve fuel efficiency and reduce their environmental impact. While select major carriers appear to be leading efforts to adopt technologies that support a dramatic improvement in fuel performance, there appears to be little understanding as to the breadth and depth of efforts being taken by the broader motor carrier community, consisting of over 20,000 companies of all sizes. The purpose of this study was to investigate the level of adoption of technologies and policies to support improved fuel efficiency among motor carrier fleets.
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In crop rotations that include alfalfa (Medicago sativa L.), agronomic and environmental concerns mean that it is important to determine the N fertilizer contribution of this legume for subsequent crops in order to help to increase the sustainability of cropping systems. To determine the N fertilizer replacement value (FRV) of a 2-yr alfalfa crop on subsequent crops of corn (Zea mays L.) followed by wheat (Triticum aestivum L.) under irrigated Mediterranean conditions, two 4-yr rotations (alfalfa-corn-wheat and corn-corn-corn-wheat) were conducted from 2001 to 2004 in a Typic Xerofluvent soil. Corn yields were compared after two years of alfalfa and a third year of corn under monoculture and wheat yields were also compared after both rotations. Corn production after alfalfa outyielded monoculture corn at all four rates of N fertilizer application analyzed (0, 100, 200 and 300 kg N/ha). The FRV of 2-yr alfalfa for corn was about 160 kg N/ha. Wheat grown after the alfalfa-corn rotation outyielded that grown after corn under monoculture at both the rates of N studied (0 and 100 kg N/ha). The FRV of alfalfa for wheat following alfalfa-corn was about 76 kg N/ha. Soil NO3 -N content after alfalfa was greater than with the corn monoculture at all rates of N fertilizer application and this higher value persisted during the second crop after alfalfa. This was probably one of the reasons for the better yields associated with the alfalfa rotation. These results make a valuable contribution to irrigated agriculture under mediterranean conditions, show reasons for interest in rotating alfalfa with corn, and explain how it is possible to make savings when applying N fertilizer.
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This book comprises two volumes and builds on the findings of the DISMEVAL project (Developing and validating DISease Management EVALuation methods for European health care systems), funded under the European Union's (EU) Seventh Framework Programme (FP7) (Agreement no. 223277). DISMEVAL was a three-year European collaborative project conducted between 2009 and 2011. It contributed to developing new research methods and generating the evidence base to inform decision-making in the field of chronic disease management evaluation (www.dismeval.eu). In this book, we report on the findings of the project's first phase, capturing the diverse range of contexts in which new approaches to chronic care are being implemented and evaluating the outcomes of these initiatives using an explicit comparative approach and a unified assessment framework. In this first volume, we describe the range of approaches to chronic care adopted in 12 European countries. By reflecting on the facilitators and barriers to implementation, we aim to provide policy-makers and practitioners with a portfolio of options to advance chronic care approaches in a given policy context.
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In modem hitec industry Advanced Planning and Scheduling (APS) systems provide the basis for e-business solutions towards the suppliers and the customers. One objective of this thesis was to clarify the modem supply chain management with the APS systems and especially concentrate on the area of Collaborative Planning. In order Advanced Planning and Scheduling systems to be complete and usable, user interfaces are needed. Current Visual Basic user interfaces have faced many complaints and arguments from the users as well as from the development team. This thesis is trying to analyze the reasons and causes for the encountered problems and also provide ways to overcome them. The decision has been made to build the new user interfaces to be Web-enabled. Therefore another objective of this thesis was to research and find suitable technologies for building the Web-based user interfaces for Advanced Planning and Scheduling Systems in Nokia Demand/Supply Planning business area. Comparison between the most suitable technologies is made. Usability issues of Web-enabled user interfaces are also covered. The empirical part of the thesis includes design and implementation of a Web-based user interface with the chosen technology for a particular APS module that enables Collaborative Planning with suppliers.
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The phyllochron is defined as the time required for the appearance of successive leaves on a plant; this characterises plant growth, development and adaptation to the environment. To check the growth and adaptation in cultivars of strawberry grown intercropped with fig trees, it was estimated the phyllochron in these production systems and in the monocrop. The experiment was conducted in greenhouses at the University of Passo Fundo (28º15'41'' S, 52º24'45'' W and 709 m) from June 8th to September 4th, 2009; this comprised the period of transplant until the 2nd flowering. The cultivars Aromas, Camino Real, Albion, Camarosa and Ventana, which seedlings were originated from the Agrícola LLahuen Nursery in Chile, as well as Festival, Camino Real and Earlibrite, originated from the Viansa S.A. Nursery in Argentina, were grown in white polyethylene bags filled with commercial substrate (Tecnomax®) and evaluated. The treatments were arranged in a randomised block design and four replicates were performed. A linear regression was realized between the leaf number (LN) in the main crown and the accumulated thermal time (ATT). The phyllochron (degree-day leaf-1) was estimated as the inverse of the angular coefficient of the linear regression. The data were submitted to ANOVA, and when significance was observed, the means were compared using the Tukey test (p < 0.05). The mean and standard deviation of phyllochrons of strawberry cultivars intercropped with fig trees varied from 149.35ºC day leaf-1 ± 31.29 in the Albion cultivar to 86.34ºC day leaf-1 ± 34.74 in the Ventana cultivar. Significant differences were observed among cultivars produced in a soilless environment with higher values recorded for Albion (199.96ºC day leaf-1 ± 29.7), which required more degree-days to produce a leaf, while cv. Ventana (85.76ºC day leaf-1 ± 11.51) exhibited a lower phyllochron mean value. Based on these results, Albion requires more degree-days to issue a leaf as compared to cv. Ventana. It was conclude that strawberry cultivars can be grown intercropped with fig trees (cv. Roxo de Valinhos).
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The objective of the thesis is to enhance the understanding about the management of the front end phases of the innovation process in a networked environment. The thesis approaches the front end of innovation from three perspectives, including the strategy, processes and systems of innovation. The purpose of the use of different perspectives in the thesis is that of providing an extensive systemic view of the front end, and uncovering the complex nature of innovation management. The context of the research is the networked operating environment of firms. The unit of analysis is the firm itself or its innovation processes, which means that this research approaches the innovation networks from the point of view of a firm. The strategy perspective of the thesis emphasises the importance of purposeful innovation management, the innovation strategy of firms. The role of innovation processes is critical in carrying out innovation strategies in practice, supporting the development of organizational routines for innovation, and driving the strategic renewal of companies. The primary focus of the thesis from systems perspective is on idea management systems, which are defined as a part of innovation management systems, and defined for this thesis as any working combination of methodology and tools (manual or IT-supported) that enhance the management of innovations within their early phases. The main contribution of the thesis are the managerial frameworks developed for managing the front end of innovation, which purposefully “wire” the front end of innovation into the strategy and business processes of a firm. The thesis contributes to modern innovation management by connecting the internal and external collaboration networks as foundational elements for successful management of the early phases of innovation processes in a dynamic environment. The innovation capability of a firm is largely defined by its ability to rely on and make use of internal and external collaboration already during the front end activities, which by definition include opportunity identification and analysis, idea generation, profileration and selection, and concept definition. More specifically, coordination of the interfaces between these activities, and between the internal and external innovation environments of a firm is emphasised. The role of information systems, in particular idea management systems, is to support and delineate the innovation-oriented behaviour and interaction of individuals and organizations during front end activities. The findings and frameworks developed in the thesis can be used by companies for purposeful promotion of their front end processes. The thesis provides a systemic strategy framework for managing the front end of innovation – not as a separate process, but as an elemental bundle ofactivities that is closely linked to the overall innovation process and strategy of a firm in a distributed environment. The theoretical contribution of the thesis relies on the advancement of the open innovation paradigm in the strategic context of a firm within its internal and external innovation environments. This thesis applies the constructive research approach and case study methodology to provide theoretically significant results, which are also practically beneficial.
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Field experiments were conducted in the 1995-96 soybean (Glycine max) growing season to evaluate the effects of cultural practices and host genetic resistance on the intensity of soybean stem canker, caused by Diaporthe phaseolorum f.sp. meridionalis (Dpm). Experiments were conducted in a commercial field severely infected in the previous (1994-95) season. In one study, minimum tillage (MT) and no-tillage (NT) cropping systems were investigated for their effects on disease development and on plant yields in cvs. FT-Cristalina (susceptible) and FT-Seriema (moderately resistant). Another study evaluated the effects of plant densities (8, 15, 21 and 36 plants/m) on disease development in cvs. FT-Cristalina, FT-101 (moderately resistant) and FT-104 (resistant). Disease incidence and severity were consistently lower in NT than in MT, and plant yields were increased by 23% and 14% in the NT system for the susceptible and moderately resistant cultivars, respectively, compared to the yields in the MT system. The Gompertz and Logistic models described well the disease progress curves in all situations. For both susceptible and moderately resistant cultivars, disease severity increased proportionately to the increase in plant densities. At the end of the season, 100% of the plants of cv. FT-Cristalina were infected by Dpm, at all plant densities. Disease levels on cv. FT-101 were intermediate while only very low disease levels were recorded on cv. FT-104. There was a consistent negative correlation between stem canker severity and yield. Some practices demonstrated potential for direct application in disease control, and could be combined considering their additive effects.
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The etiology and epidemiology of Pythium root rot in hydroponically-grown crops are reviewed with emphasis on knowledge and concepts considered important for managing the disease in commercial greenhouses. Pythium root rot continually threatens the productivity of numerous kinds of crops in hydroponic systems around the world including cucumber, tomato, sweet pepper, spinach, lettuce, nasturtium, arugula, rose, and chrysanthemum. Principal causal agents include Pythium aphanidermatum, Pythium dissotocum, members of Pythium group F, and Pythium ultimum var. ultimum. Perspectives are given of sources of initial inoculum of Pythium spp. in hydroponic systems, of infection and colonization of roots by the pathogens, symptom development and inoculum production in host roots, and inoculum dispersal in nutrient solutions. Recent findings that a specific elicitor produced by P. aphanidermatum may trigger necrosis (browning) of the roots and the transition from biotrophic to necrotrophic infection are considered. Effects on root rot epidemics of host factors (disease susceptibility, phenological growth stage, root exudates and phenolic substances), the root environment (rooting media, concentrations of dissolved oxygen and phenolic substances in the nutrient solution, microbial communities and temperature) and human interferences (cropping practices and control measures) are reviewed. Recent findings on predisposition of roots to Pythium attack by environmental stress factors are highlighted. The commonly minor impact on epidemics of measures to disinfest nutrient solution as it recirculates outside the crop is contrasted with the impact of treatments that suppress Pythium in the roots and root zone of the crop. New discoveries that infection of roots by P. aphanidermatum markedly slows the increase in leaf area and whole-plant carbon gain without significant effect on the efficiency of photosynthesis per unit area of leaf are noted. The platform of knowledge and understanding of the etiology and epidemiology of root rot, and its effects on the physiology of the whole plant, are discussed in relation to new research directions and development of better practices to manage the disease in hydroponic crops. Focus is on methods and technologies for tracking Pythium and root rot, and on developing, integrating, and optimizing treatments to suppress the pathogen in the root zone and progress of root rot.
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It is generally accepted that the development of the modern sciences is rooted in experiment. Yet for a long time, experimentation did not occupy a prominent role, neither in philosophy nor in history of science. With the 'practical turn' in studying the sciences and their history, this has begun to change. This paper is concerned with systems and cultures of experimentation and the consistencies that are generated within such systems and cultures. The first part of the paper exposes the forms of historical and structural coherence that characterize the experimental exploration of epistemic objects. In the second part, a particular experimental culture in the life sciences is briefly described as an example. A survey will be given of what it means and what it takes to analyze biological functions in the test tube.
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The use of fertilizers and solid amendments in agriculture generates special interest for their effect on crop productivity, as well as for their environmental impact. The efficient use of these products demands knowing their physical and mechanical properties, the storing conditions effect and the operational characteristics of the metering systems used in the fertilizing equipment. In this context, the present study was developed with the purpose of evaluating the operational characteristics of different fertilizing metering systems and to determine the adequate metering system-product operational parameters, using powder lime, powder gypsum, granular 10-30-10 (N-P-K), and granular urea. Operational differences were established among four types of commercial fertilizer metering systems, including wire auger, star-shaped feed wheel, feed screw and ridged traction wheel. The study found that the unloading rate depends directly on the fertilizer metering system's rotating speed and is affected by particle size, repose angle, bulk density and moisture content of the applied product. The wire auger and star-shaped feed wheel metering systems were adequate for the distribution of powder products and the feed screw for granulated fertilizers. Furthermore, theoretical and experimental characteristic equations were established, defining curves for calibration and handling of the products plus the rotating speed range in which a better distributing behavior was achieved.
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Under organic management in Seropédica-RJ, Brazil, using a weighing lysimeter, the crop coefficients (kc), the maximum evapotranspiration and the productivity of eggplant cultivation under two cropping systems (no tillage with straw plus soil with conventional preparation) were determined. A whole randomized layout with two treatments (no tillage and conventional) and five replicates during 134 days of cultivation were adopted. There were no significant differences in the eggplant cultivation in the two cropping systems, with a maximum commercial productivity obtained from 47.42 Mg ha-1 for the no-tillage system, and 47.91 Mg ha-1 for the conventional tillage. The accumulated ETc was 285.15 and 323.44 mm for the no-tillage and conventional, respectively. The crop coefficients value for the phases: 1 - transplanting, flowering, 2 - flowering-fruiting, 3 - fruit- first harvesting, 4- first harvesting of the final crop cycle was 0.83, 0.77, 0.90 and 0.97 in no-tillage system for the respective phases and for the conventional one 0.81, 1.14, 1.17 and 1.05 for the same steps described above.