ABSTRACT The purpose of this study was to conduct a cultural energy analyses of beef cattle receiving different levels of concentrate. Data were obtained via questionnaire from 100 beef cattle farms selected by a stratified, random sampling method. Beef cattle farms were divided into three groups according to concentrate level and were analyzed. Accordingly concentrate levels were assigned as low (< 55% 35 farms), intermediate (55% to 65%, 34 farms) and high (> 65%, 31 farms). Cultural energy used for feed for treatments was derived from their corresponding lot feed consumption and their corresponding values from the literature. Transportation energy was also included in the analysis. Since the objective of the study was to evaluate cultural energy analysis of the feeding systems, energy that the calves had deposited in their muscle and fat tissue when they were bought was deducted from carcass energy. Total cultural energy expended was highest for cattle receiving a low level of concentrate (p < 0.05). Feed energy constituted more than half of the total cultural energy and was highest for cattle receiving a low level of concentrate (p < 0.05). Energy expended per kg live weight did not differ among groups by concentrate level (p > 0.05). Cultural energy per Mcal protein energy was highest for cattle receiving a low level of concentrate and was lowest for cattle receiving an intermediate level of concentrate (p < 0.05). Cultural energy for cattle receiving a high level of concentrate was intermediate and thus did not differ significantly from the other groups (p > 0.05). Efficiency, defined as Mcal input/Mcal output, was better for cattle receiving an intermediate level of concentrate and was worse for cattle receiving a low level of concentrate (p < 0.05). Efficiency for cattle receiving a high level of concentrate was intermediate and thus did not differ significently from the other groups (p > 0.05). Results showed that efficiency does not linearly increase as concentrate level increases; thus, in order to be more sustainable, a strategy of decreasing concentrate level without interfering with cattle performance should be considered.
This article sketches a brief panorama of the advances and challenges involved in the implementation of the agroecological approach in Brazilian institutions. It begins with an account of the struggles of rural social movements working at the deepest grassroots level of the country's “agroecological field.” The processes that led to the creation and development of the National Agroecology Alliance (ANA) and the Brazilian Agroecology Association (ABA-Agroecologia) are presented as a key part of the construction now under way. Taking as a baseline the evolutions in the internalization of agroecology in official teaching, research, and rural extension services, the article identifies some of the powerful practical, theoretical, and politico-ideological obstacles preventing the rupture with the paradigm of modernization on the part of state institutions.
Monsampolo Organic VEgetable (MOVE) long-term field experiment produced a comparison between organic and a conventionally managed agroecosystem for vegetable production in Central Italy. The study was based on a four-year crop rotation involving six main crops: tomato, melon, fennel, lettuce, cauliflower, and bean. The experiment started in 2001. The agronomic performance and environmental sustainability of the two different management systems were assessed over a three-year period (2007–2010), comparing a) the yield and produce quality; b) cultivar adaptability to organic farming conditions; c) soil quality; and d) potential risk of soil nitrogen leaching. The organic and conventional four-years rotation systems yielded similarly and most of the crops showed no significant differences in produce quality. The study also indicates that comparisons among cultivars to be used in organic farming should be carried out on such experimental field sites where organic farming management had been in place for the long term. Our study demonstrated that soil organic C and total N increased, respectively, of 37% and 22% in the organically managed vegetable production system as compared to the conventional one. The risks of soil nitrate leaching were higher in autumn/winter conventionally managed crops as compared to the organic ones.
The contribution of cover crop roots to soil dynamics is poorly understood, in part because little information is available on the distribution, depth, chemical compositional changes over time, and nutrient mineralization rates of typical cover crop roots. A study was conducted to investigate the role of cover crop roots in a long-term trial on the effects of cover crop species and seasonal placement on soil properties in a vegetable rotation. Root length density (RLD), chemical composition, and nitrogen mineralization during incubation were measured in roots of red clover (Trifolium pratense L.) and winter rye (Secale cereale L.) of varying ages. Nearly 50% of the fine root RLD was measured in the top 5 cm for all roots, with no significant differences between species and ages. Lignin concentration in red clover roots increased nearly four-fold as they aged from 4 to 24 months, while N concentration were 22% lower in the older roots. N concentration decreased by 50% in rye roots from 0 to 9 months, leading to doubling of C:N. During incubation, net N mineralization was greater from 24 month-old red clover roots than 12-month roots, while winter rye roots showed net N immobilization over the incubation period.
Organic grain production is not common to eastern Washington, but offers attractive market opportunities if systems can be developed that are compatible with regional production constraints. Erodible soils make tillage-intensive systems unsustainable, and there are limited alternative fertility options. Given these constraints, the objective of this study was to evaluate nine cropping systems during the transition to organic grain production under reduced tillage and relying on legumes as the primary source of crop nitrogen. The experimental transition systems ranged in the degree in which legume grain crops or legume green manures/forages were present in the rotation. We found that spring pea grown for grain to be a poor choice for organic production due to the susceptibility of this crop to insect pests and weeds, which generally resulted in crop failure. Likewise, bell bean was poorly suited as a legume green manure crop due to its low productivity in our region. In contrast, alfalfa and winter pea-based systems achieved the best legume biomass production, weed suppression, and crop yields in the subsequent crops. Winter wheat substantially out-yielded spring wheat, but the yields of both of these crops were well below the yield potential typically achieved under conventional production. Competition from annual weeds, such as wild oat and prickly lettuce, and the perennial weed field bindweed was difficult to manage under the reduced tillage regimes employed in this study.
Olive fly activity in a commercial organic table olive orchard was monitored for 80 weeks using McPhail traps for two successive years, a fruiting and a non-fruiting year. Mass traps were employed from the end of May to limit fruit damage. In the fruiting year, fly activity increased steadily with a peak in June–July but there was very little activity after July for both years. The lack of activity from July onward was reflected in very low fruit infestation in the fruiting year. Mean maximum temperatures were generally 34–35oC from July to September. High mortality of olive fly adults, eggs, and larvae was likely because of sustained high temperatures. The trend in Mediterranean olive growing areas appears to be for increasing summer temperatures and olive fly control measures may have to take into account aspects of climate fluctuation.
Molly Anderson, Food and Sustainable Agriculture Systems, College of the Atlantic, Bar Harbor, ME Dave Archer, Agricultural Economics, Northern Great Plains Research Lab, USDA, ARS, Mandan, ND Marta Astier, Centro de Investigaciones en Geografía Ambiental, Universidad Nacional Autónoma de México, Morelia, MEXICO Eunice Bacelar, Biological and Environmental Engineering, Center for Technological, Environmental, and Life Studies, Vila Real, PORTUGAL Marcus Buchanan, Consulting Agroecologist, Buchanan Associates, Jacksonville, OR Irene Cardoso, Soils Department, Universidade do Viçosa, BRAZIL Oscar Carpintero, Department of Applied Economics, Universidad de Valladolid, SPAIN Harun Cicek, Organic Cropping Systems, University of Manitoba, Winnipeg, CANADA Christopher Clark, Department of Plant Pathology and Crop Physiology, Louisiana State University, Baton Rouge, LA Angel Calle Collado, Instituto de Sociología y Estudios Campesinos, Universidad de Córdoba, Córdoba, SPAIN Xavier Cusso, Facultad de Economía, Universidad Autónoma de Barcelona, Barcelona, SPAIN Goretty Dias, Environment, Enterprise, and Development, University of Waterloo, Ontario, CANADA Bernard Freyer, Department of Sustainable Agricultural Studies, University of Natural Resources and Life Sciences, Vienna, AUSTRIA Thomas Gaiser, Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, GERMANY Alex Gershenson, Environmental Studies, San Jose State University, San Jose, CA Karamjit Singh Gill, Human Centred Systems, University of Brighton, UK Marco Antonio Giron Tejada, Imecol SA Colombia, Cali, COLOMBIA Stuart Hill, School of Education, University of Western Sydney, Penrith, New South Wales, AUSTRALIA Eric Holt-Gimenez, Food First, Oakland, CA Randall Ireson, Rural Development Solutions, Salem, OR
This article examines the sustainability of livelihoods through urban agriculture (UA): gender dimensions in Accra, Ghana. The population used for the study was the vegetable producers within and around Accra, Ghana. A mix of sampling techniques was followed in choosing UA producers. While a random sampling technique was employed in choosing male UA producers, all female producers who were willing to be interviewed were chosen. In all, 92 male producers and 8 female producers gave consistent responses that were analyzed. The results show that the mean age for male producers is 39.4 years. Female producers are more elderly with a mean age of 49.8 years. The mean year of schooling is 6.4 years for male producers and 7.1 years for female producers. While all the households are involved in irrigated farming, only 13% male and 25% female managed farms practiced irrigated farming alone. The majority of the male and female farmers indicated that high contribution of urban agriculture to their livelihoods. Farm size and access to credit were significant determinants of income from urban agriculture among the respondents.
The concept of agroecology in the United States is born out of a dialectical process of co-production of knowledge whereby the science of agroecology has shaped and been shaped by alternative agri-food movements, policy, and local practice. This article examines the relationship between agroecology and alternative agri-food movements and identifies opportunities for greater engagement. The article concludes with a discussion of the challenges and opportunities to scaling up agroecology and sustainable agri-food systems.
High oil dependence and energy inefficiency are structural characteristics of industrialized agricultural systems. In a context of climate change and growing energy shortage as the present one, energy indicators should be increasingly taken into account as measures of environmental sustainability, efficiency, and technical-productive viability in analyses and decision-making processes in the field of agriculture. One of the most relevant characteristics of agriculture is its capacity to transform energy and to generate an energy surplus that has very diverse uses (human feeding, animal feeding, fertilization, etc.). This energy surplus is potentially greater in organic farming. However, empirical studies analyzing the aggregate energy performance of organic farming and allowing an assessment of the scope and energy limitations of this type of production are few. This work analyses the energy performance of organic farming in Andalusia, the southern region of Spain, both in an aggregate form and by large groups of crops, through the energy assessment of its output, inputs and energy efficiency (ER). The energy ratio of Andalusian organic farming in 2005 was estimated by 1.40, the extensive crops (2.86), horticultural crops (0.18), citrus fruits (0.39), subtropical fruits (0.85), other fruits (1.64), nuts (0.54), olive (2.08), and vine (0.76).
The serious problems of agrarian unsustainability cannot be solved through technological changes that lessen environmental impacts. Although technological change is important, it is also necessary to change the agri-food system as a whole. Participatory action research (PAR) is a methodological approach to collaborate with local communities. It enables us to advance in the restructuring of physical flows, economies, and information that support local farming, as a means to achieve greater autonomy and self-management. This article presents several case studies in Spain in which PAR has been applied to build local organic food networks. These are characterized by a more sustainable use of local resources and the development of short food supply chains.
An important premise of agroecology is that, in order to transition toward sustainability, it is necessary to redesign agroecosystems so that they can function on the basis of a different set of ecological principles. These principles are grounded in interaction, complementarity, and relationships in systems that give the ability to resist the problems that industrial agriculture controls with an impressive array of inputs and practices. Even organic systems depending primarily on the substitution of these inputs and practices with those accepted by organic certification organizations encounter the same set of problems, especially when the cropping system is reduced in diversity. Increase the size and scale of the operation, as has become the case for some commercial organic monocultures, and input intensity goes up even more as problems become more difficult to manage. Working collaboratively, teams of farmers and agroecologists have begun to test these different designs and, in the process, are gathering scientific data and practical experience that provide examples of how the redesign process can work. The research experiences presented in this issue of JSA are some of these examples. By adding covercrops, associated and intercropped species, or alternative rotations, there is a chance for some of the complexity needed for ecosystem processes to be successful. Be it for pest management, disease control, or fertility maintenance, these processes internalize input management and reduce the dependence of the agroecosystem on external sources. JSA hopes that more farmer and researcher teams will continue to test more complexity and interactions, and that the journal can be a place to report their results.
The Journal of Sustainable Agriculture puts forth a special issue, entitled, “Agroecology and the Transformation of Agro-Food Systems: Transdisciplinary and Participatory Perspectives.” This issue will examine recent trends in agroecology that view the field as a transdisciplinary and participatory process, which seeks to actively engage social actors to transform the global agro-food system. This agroecological perspective looks to analyze and engage actors and social processes at different geopolitical scales. Much of the work aligned with this approach is characterized by the use of transdisciplinary and participatory action research (PAR). The first can be defined as an approach that integrates, not only different academic disciplines (especially the social with the natural sciences), but also values and includes different forms of knowledge and practice (e.g., experiential, cultural, spiritual, etc.).The second is a way of engaging all relevant actors in an effort to attain an equitable process of research, reflection, and engagement on areas of desirable social change. Agroecology is defined as the integration of science, practice, and social movements in food systems. To truly be agroecology, this integration is a necessity.
We studied the soil quality and the response of olive trees (Olea europaea L.) to organic agriculture. Three factors were considered: management (organic and conventional), soil parent material (calcareous colluvium and marl), and slope (upper, middle, and lower). An increase in soil quality was observed in organic plots and colluvial soils. Moreover, we noticed an increase in the assimilation rate of CO2 and lower water deficit in leaves of trees under organic management, which are of great importance in semi-arid environments. These results indicate a relationship between soil quality and physiological responses of olive trees that should be taken into account by agronomists and policymakers.
The world seeks to balance biodiversity protection and food production. Transfrontier conservation areas (TFCAs) provide unique opportunities for strategies that combine agriculture with biodiversity conservation at a landscape level, known as ecoagriculture. We identified and consulted ecoagriculture stakeholders in a smallholder farming community within a TFCA. Data were obtained through key informant interviews and questionnaire surveys. Eighty-eight percent of key informants indicated that planned ecoagriculture was feasible in the area and 95% of interviewed farmers positively considered to plan the integration of biodiversity conservation and farming. Potential conflicts of interest were revealed among stakeholders but to a large extent, stakeholder roles and interests were complementary, creating an environment conducive to effective coordinated ecoagriculture planning.
The knowledge of traditional farmers is encyclopedic and ever changing as they continue learning from experiments and mutual interchange in the actualization of agroecology. The modern science of ecology is (or should be) the scientific basis of agroecology and should synergistically inform the ongoing accumulation of knowledge inherent in the practice of small-scale farmers. Traditional agricultural knowledge is deep but narrow, while modern ecological knowledge is broad but shallow. The intersection of traditional knowledge with modern ecology could result in the generation of knowledge that is simultaneously deep and broad.
Coffee is grown widely throughout the tropics on about 5 million farms from 85 countries. Several studies carried out during the last decade revealed the importance of traditional shaded coffee for biodiversity maintenance and protection. However, there is only biological and no interdisciplinary exploration of the multiple values and benefits of these agroforestry systems. We identify and review four kinds of nonbiological values, which complement its tested importance as a refuge for tropical biodiversity, as a contribution to the complete valuation of traditional shaded coffee. By briefly describing a case study in Mexico, we show how traditional shade-grown coffee is critical for areas where sustainable projects are being implemented. This article concludes by exploring three key dimensions of sustainability: economy, landscapes, and livelihoods.
A new a study from McGill University and the University of Minnesota published in the journal Nature compared organic and conventional yields from 66 studies and 316 trials (Seufert et al. 2012). R...
