Transgenic plants for tropical regions: some considerations about their development and their transfer to the small farmer.
(17/1030)
Biotechnological applications, especially transgenic plants, probably hold the most promise in augmenting agricultural production in the first decades of the next millennium. However, the application of these technologies to the agriculture of tropical regions where the largest areas of low productivity are located, and where they are most needed, remains a major challenge. In this paper, some of the important issues that need to be considered to ensure that plant biotechnology is effectively transferred to the developing world are discussed. (+info)
From pre-hispanic to future conservation alternatives: lessons from Mexico.
(18/1030)
In this paper, we review some past and present trends in biodiversity conservation in Mexico and explore possible explanations of why, in spite of this long history of depredation and ineffective conservation policies, the ecosystems have been able to cope with and retain most of their biological components. We suggest a hypothesis based on the persistence of a complex mosaic of past and present traditional land uses as a possible explanation for this resilience. We propose an agenda for the scope of future conservation research and policy, particularly the need to take the socioeconomic context of environmental degradation into account. We put forth a series of questions that we think need to be investigated if the conservation research community is to participate in developing solutions for the future welfare of the human species and of biodiversity on earth. (+info)
Gardenification of tropical conserved wildlands: multitasking, multicropping, and multiusers.
(19/1030)
Tropical wildlands and their biodiversity will survive in perpetuity only through their integration into human society. One protocol for integration is to explicitly recognize conserved tropical wildlands as wildland gardens. A major way to facilitate the generation of goods and services by a wildland garden is to generate a public-domain Yellow Pages for its organisms. Such a Yellow Pages is part and parcel of high-quality search-and-delivery from wildland gardens. And, as they and their organisms become better understood, they become higher quality biodiversity storage devices than are large freezers. One obstacle to wildland garden survival is that specific goods and services, such as biodiversity prospecting, lack development protocols that automatically shunt the profits back to the source. Other obstacles are that environmental services contracts have the unappealing trait of asking for the payment of environmental credit card bills and implying delegation of centralized governmental authority to decentralized social structures. Many of the potential conflicts associated with wildland gardens may be reduced by recognizing two sets of social rules for perpetuating biodiversity and ecosystems, one set for the wildland garden and one set for the agroscape. In the former, maintaining wildland biodiversity and ecosystem survival in perpetuity through minimally damaging use is paramount, while in the agroscape, wild biodiversity and ecosystems are tools for a healthy and productive agroecosystem, and the loss of much of the original is acceptable. (+info)
Global environmental impacts of agricultural expansion: the need for sustainable and efficient practices.
(20/1030)
The recent intensification of agriculture, and the prospects of future intensification, will have major detrimental impacts on the nonagricultural terrestrial and aquatic ecosystems of the world. The doubling of agricultural food production during the past 35 years was associated with a 6.87-fold increase in nitrogen fertilization, a 3.48-fold increase in phosphorus fertilization, a 1.68-fold increase in the amount of irrigated cropland, and a 1.1-fold increase in land in cultivation. Based on a simple linear extension of past trends, the anticipated next doubling of global food production would be associated with approximately 3-fold increases in nitrogen and phosphorus fertilization rates, a doubling of the irrigated land area, and an 18% increase in cropland. These projected changes would have dramatic impacts on the diversity, composition, and functioning of the remaining natural ecosystems of the world, and on their ability to provide society with a variety of essential ecosystem services. The largest impacts would be on freshwater and marine ecosystems, which would be greatly eutrophied by high rates of nitrogen and phosphorus release from agricultural fields. Aquatic nutrient eutrophication can lead to loss of biodiversity, outbreaks of nuisance species, shifts in the structure of food chains, and impairment of fisheries. Because of aerial redistribution of various forms of nitrogen, agricultural intensification also would eutrophy many natural terrestrial ecosystems and contribute to atmospheric accumulation of greenhouse gases. These detrimental environmental impacts of agriculture can be minimized only if there is much more efficient use and recycling of nitrogen and phosphorus in agroecosystems. (+info)
Nitrogen management and the future of food: lessons from the management of energy and carbon.
(21/1030)
The food system dominates anthropogenic disruption of the nitrogen cycle by generating excess fixed nitrogen. Excess fixed nitrogen, in various guises, augments the greenhouse effect, diminishes stratospheric ozone, promotes smog, contaminates drinking water, acidifies rain, eutrophies bays and estuaries, and stresses ecosystems. Yet, to date, regulatory efforts to limit these disruptions largely ignore the food system. There are many parallels between food and energy. Food is to nitrogen as energy is to carbon. Nitrogen fertilizer is analogous to fossil fuel. Organic agriculture and agricultural biotechnology play roles analogous to renewable energy and nuclear power in political discourse. Nutrition research resembles energy end-use analysis. Meat is the electricity of food. As the agriculture and food system evolves to contain its impacts on the nitrogen cycle, several lessons can be extracted from energy and carbon: (i) set the goal of ecosystem stabilization; (ii) search the entire production and consumption system (grain, livestock, food distribution, and diet) for opportunities to improve efficiency; (iii) implement cap-and-trade systems for fixed nitrogen; (iv) expand research at the intersection of agriculture and ecology, and (v) focus on the food choices of the prosperous. There are important nitrogen-carbon links. The global increase in fixed nitrogen may be fertilizing the Earth, transferring significant amounts of carbon from the atmosphere to the biosphere, and mitigating global warming. A modern biofuels industry someday may produce biofuels from crop residues or dedicated energy crops, reducing the rate of fossil fuel use, while losses of nitrogen and other nutrients are minimized. (+info)
Nationwide implementation of guided supermarket tours in The Netherlands: a dissemination study.
(22/1030)
The purpose of this study was to assess adoption, implementation and maintenance of a guided supermarket tour program of nutrition education by Dutch Public Health Services (PHSs), and the factors associated with program dissemination. A first questionnaire was sent to all 60 PHSs, and measured program adoption, perceived program attributes, and characteristics of the adopting organization and person. A second questionnaire was only sent to adopting PHSs, and measured extent and success of implementation, intentions to continue the program, and characteristics of the main implementing person. Of the 59 PHSs who responded, 30 adopted the program and 17 implemented it sufficiently. Perceived program complexity, social influence within the PHS toward program participation and existence of a separate health education department were predictors of adoption. Perceived program complexity was also a predictor of extent of implementation. The number of health educators within each PHS was a predictor of sufficient implementation. It was concluded that adoption and implementation of the program was reasonable, considering the limited dissemination strategy. Dissemination might have been more successful if the program had been less complex and required less effort, if positive social influence had been generated, and if specific attention had been given to PHSs without a separate health education department. (+info)
The effectiveness of a short form of the Household Food Security Scale.
(23/1030)
OBJECTIVES: On the basis of an 18-item Household Food Security Scale, a short form was developed to assess financially based food insecurity and hunger in surveys of households with and without children. METHODS: To maximize the probability that households would be correctly classified with respect to food insecurity and hunger, 6 items from the full scale were selected on the basis of April 1995 Current Population Survey data. RESULTS: The short form classified 97.7% of households correctly and underestimated the prevalence of overall food insecurity and of hunger by 0.3 percentage points. CONCLUSIONS: The short form of the Household Food Security Scale is a brief but potentially useful tool for national surveys and some state/local applications. (+info)
Effectiveness of food fortification in the United States: the case of pellagra.
(24/1030)
OBJECTIVES: We evaluated the possible role of niacin fortification of the US food supply and other concurrent influences in eliminating the nutritional deficiency disease pellagra. METHODS: We traced chronological changes in pellagra mortality and morbidity and compared them with the development of federal regulations, state laws, and other national activities pertaining to the fortification of cereal-grain products with niacin and other B vitamins. We also compared these changes with other concurrent changes that would have affected pellagra mortality or morbidity. RESULTS: The results show the difficulty of evaluating the effectiveness of a single public health initiative such as food fortification without controlled experimental trials. Nonetheless, the results provide support for the belief that food fortification played a significant role in the elimination of pellagra in the United States. CONCLUSIONS: Food fortification that is designed to restore amounts of nutrients lost through grain milling was an effective tool in preventing pellagra, a classical nutritional deficiency disease, during the 1930s and 1940s, when food availability and variety were considerably less than are currently found in the United States. (+info)