52 research outputs found
Nitrogen balance and root behavior in four pigeonpea-based intercropping systems
A medium-duration pigeonpea (Cajanus cajan L. Millsp.) is usually grown as intercrop. A wide range of crop combination in pigeonpea-based intercropping systems is found in India and eastern Africa (Ofroi and Stern, 1987; Rao and Willey, 1980; Venkateswarlu and Subramanian, 1990). Although much information is available on the production efficiency and monetary advantage of intercropping, very little is known about the nitrogen (N) economy and root behavior. The study was carried out to examine how the nitrogen balance sheet and root development of pigeonpea could be altered by companion crops
SYMBIOTIC EFFECTIVENESS AND COMPETITIVENESS OF CALOPO RHIZOBIAL ISOLATES IN AN ARGISSOLO VERMELHO-AMARELO UNDER THREE VEGETATION COVERS IN THE DRY FOREST ZONE OF PERNAMBUCO
Clinical review: Allocating ventilators during large-scale disasters – problems, planning, and process
Catastrophic disasters, particularly a pandemic of influenza, may force difficult allocation decisions when demand for mechanical ventilation greatly exceeds available resources. These situations demand integrated incident management responses on the part of the health care facility and community, including resource management, provider liability protection, community education and information, and health care facility decision-making processes designed to allocate resources as justly as possible. If inadequate resources are available despite optimal incident management, a process that is evidence-based and as objective as possible should be used to allocate ventilators. The process and decision tools should be codified pre-event by the local and regional healthcare entities, public health agencies, and the community. A proposed decision tool uses predictive scoring systems, disease-specific prognostic factors, response to current mechanical ventilation, duration of current and expected therapies, and underlying disease states to guide decisions about which patients will receive mechanical ventilation. Although research in the specifics of the decision tools remains nascent, critical care physicians are urged to work with their health care facilities, public health agencies, and communities to ensure that a just and clinically sound systematic approach to these situations is in place prior to their occurrence
Fertilizing Methods and Nutrient Balance at the End of Traditional Organic Agriculture in the Mediterranean Bioregion: Catalonia (Spain) in the 1860s
By reconstructing the nutrient balance of a Catalan v illage circa 1861-65 we examine the sustainability of organic agricultural sy stems in the northwest Mediterranean bioregion prior to the green rev olution and the question of whether the nutrients extracted f rom the soil were replenished. With a population density of 59 inhabitants per square km, similar to other northern European rural areas at that time, and a lower liv estock density per cropland unit, this v illage experienced a manure shortage. The gap was f illed by other labour-intensiv e way s of transf erring nutrients f rom uncultiv ated areas into the cropland. Key elements in this agricultural sy stem were v iney ards because they hav e f ew nutrient requirements, and woodland and scrublands as sources of relev ant amounts of nutrients collected in sev eral ways
Global challenges for nitrogen science-policy interactions : Towards the international nitrogen management system (INMS) and improved coordination between multi-lateral environmental agreements
Human interference with the nitrogen cycle has doubled reactive nitrogen inputs to the global biosphere over the past century, leading to changes across multiple environmental issues that require urgent action. Nitrogen fertilizers and biological nitrogen fixation have allowed benefits of increased crop harvest and livestock production, while in some areas there is insufficient nitrogen to fertilize crops. Whether in excess or deficit, nitrogen losses from its inefficient use are causing a combination of freshwater and marine pollution, air pollution, alteration of climate balance, stratospheric ozone loss, biodiversity loss and reduction of soil quality. The resulting nitrogen pollution affects human health, well-being and livelihoods. Scientific efforts have begun to bring these issues together. However, there is still a high degree of fragmentation between research on the different benefits and threats of reactive nitrogen and between the respective policy frameworks, especially at the global scale. We argue that a more joined-up approach to managing the global nitrogen cycle is needed to develop the 'gravity of common cause' between nitrogen issues and to avoid policy trade-offs. We describe how a coherent system for science evidence provision is being developed to support policy development through the 'International Nitrogen Management System' (INMS). There is now a matching challenge to bring together the multiple policy agreements relevant for nitrogen as a foundation to address synergies/trade-offs and to set priorities. Based on review of existing frameworks, we outline the concept for an Interconvention nitrogen coordination mechanism. This could make a major contribution to multiple Sustainable Development Goals by stimulating the next generation of international nitrogen strategies: maximizing the benefits of efficient nitrogen use, while minimizing its many environmental threats
Growth response of Pterocarpus santalinus seedlings to native microbial symbionts (arbuscular mycorrhizal fungi and Rhizobium aegyptiacum) under nursery conditions
- …
