186,467 research outputs found
Yield gaps, nutrient use efficiencies and response to fertilisers by maize across heterogeneous smallholder farms of western Kenya
No full textThe need to promote fertiliser use by African smallholder farmers to counteract the current decline in per capita food production is widely recognised. But soil heterogeneity results in variable responses of crops to fertilisers within single farms. We used existing databases on maize production under farmer (F-M) and researcher management (R-M) to analyse the effect of soil heterogeneity on the different components of nutrient use efficiency by maize growing on smallholder farms in western Kenya: nutrient availability, capture and conversion efficiencies and crop biomass partitioning. Subsequently, we used the simple model QUEFTS to calculate nutrient recovery efficiencies from the R-M plots and to calculate attainable yields with and without fertilisers based on measured soil properties across heterogeneous farms. The yield gap of maize between F-M and R-M varied from 0.5 to 3 t grain ha-1 season-1 across field types and localities. Poor fields under R-M yielded better than F-M, even without fertilisers. Such differences, of up to 1.1 t ha-1 greater yields under R-M conditions are attributable to improved agronomic management and germplasm. The relative response of maize to N-P-K fertilisers tended to decrease with increasing soil quality (soil C and extractable P), from a maximum of 4.4-fold to -0.5- fold relative to the control. Soil heterogeneity affected resource use efficiencies mainly through effects on the efficiency of resource capture. Apparent recovery efficiencies varied between 0 and 70% for N, 0 and 15% for P, and 0 to 52% for K. Resource conversion efficiencies were less variable across fields and localities, with average values of 97 kg DM kg-1 N, 558 kg DM kg-1 P and 111 kg DM kg-1 K taken up. Using measured soil chemical properties QUEFTS over-estimated observed yields under F-M, indicating that variable crop performance within and across farms cannot be ascribed solely to soil nutrient availability. For the R-M plots QUEFTS predicted positive crop responses to application of 30 kg P ha-1 and 30 kg P ha-1 + 90 kg N ha-1 for a wide range of soil qualities, indicating that there is room to improve current crop productivity through fertiliser use. To ensure their efficient use in sub-Saharan Africa mineral fertilisers should be: (1) targeted to specific niches of soil fertility within heterogeneous farms; and (2) go hand-in-hand with the implementation of agronomic measures to improve their capture and utilisation
Nutrient source, management system and the age of the plantation affect soil biodiversity and chemical properties in raspberry production
Full text linkSoil biodiversity is the driving force behind most soil processes. While potentially improving plant productivity and food quality, it can be negatively affected by land use and soil management. Raspberry production is part of the cultural identity of ‘La Comarca Andina’ placed within “Andina Patagonica” world biosphere reserve. In this study we assessed soil (a) chemical quality and (b) microbial biodiversity in raspberry production as affected by management (certified organic vs. current conventional practice), the source of organic nutrients (commercial vs. on-farm) and the age of the plantation. We sampled twelve plots from neighboring family farms, classified according to the management system and the source of organic nutrients, based on information recovered regarding organic certification, type of agri-food system, weeding and pests control practices, use of chemical fertilizers, tillage regime and type and rate of application of main organic amendments. In each plot we assessed soil pH, electrical conductivity (EC), organic C (SOC), total N, extractable P, soil basal respiration (SBR), biodiversity indexes (Shannon, inversed Simpson and Richness), and bacterial community structure considering separately raspberry rows and inter-rows. The effects of the management system, the source of organic nutrients and the age on soil properties varied between row and inter-row. In the row, these factors had no effects on soil
chemical properties; while the source of organic nutrients affected SBR, Shannon index and bacterial community structure. Conversely, in the inter-row, no effects of the factors were detected on SBR (the only biological property analyzed), while the management, the source of organic nutrients, age, or their interactions affected EC, extractable P and total N. Finally, associations were found between soil chemical properties and soil microbial biodiversity. In the row, diversity indexes were positively correlated with SOC and total N, while the extractable P gradient explained 42% of the variability found in community structure, likely as a result of long-term use of
high P soil amendments on P-mobilizing bacteria. These findings provide initial insights on the performance of management systems and practices applied by farmers in raspberry production, and the interactions between chemical and biological components of soil quality.Estación Experimental Agropecuaria BarilocheFil: Prack McCormick, Barbara. Universidad Nacional de Lomas de Zamora; ArgentinaFil: El Mujtar, Veronica Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: El Mujtar, Veronica Andrea. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Cardozo, Andrea Gabriela. Instituto Nacional de Tecnologia Agropecuaria (INTA). Estacion Experimental Agropecuaria Bariloche. Agencia de Extension Rural El Bolson; ArgentinaFil: Alvarez, Valeria Esther. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Alvarez, Valeria Esther. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Rodriguez, Hernan Adrian. Universidad Nacional de Lomas de Zamora; ArgentinaFil: Tittonell, Pablo Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Tittonell, Pablo Adrian. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Tittonell, Pablo Adrian. Groningen University. Groningen Institute of Evolutionary Life Sciences; Holand
Emerging responses to the COVID-19 crisis from family farming and the agroecology movement in Latin America – A rediscovery of food, farmers and collective action
Full text linkEste trabajo contó con la colaboración de 15 co-autoresIn Latin America, the so-called informal sector associated with family farming and the agroecology movements were instrumental at coping with and adapting to the COVID-19 challenges.
OBJECTIVE: To assess the nature and extent of the early initiatives (first three months) deployed by this informal sector to cope with and adapt to the impacts of the COVID-19 pandemic on food production and consumption in several countries of the region.
METHODS: We used key used informant consultation (n = 168), an online survey (n = 125) and the detailed characterisation of regional case studies (n = 4). Textual data was analysed and categorised using Reinert’s method, combined with similarity analysis.
RESULTS AND CONCLUSIONS: 65% of the initiatives were ‘local’ in terms of geographic reach, 30% of them started within the first month after the pandemic and most of them were urban or urban-rural, whereas only 29% of them were exclusively rural. The analysis of the textual information captured through the survey revealed four major types of initiatives that were deployed or adapted in response to COVID-19:
1. Direct producer-to-consumer food sales, generally existing before the COVID-19 crisis but adapted/ strengthened to cope with it;
2. Short value chains that linked rural and urban organisations and individuals supported by national or local governments, readapted through new health and safety protocols;
3. Newly developed support and training programs on sustainable food production for selfconsumption or local commerce, in rural, urban or peri-urban settings;
4. Food assistance and aid initiatives focusing on vulnerable populations, relying on solidarity networks associated with the agroecological movement.
SIGNIFICANCE: The pandemic highlighted the key role played by local food systems and value chains and the need to strengthening them through public policies, as a way to build food resilience in times of crisis.Estación Experimental Agropecuaria BarilocheFil: Tittonell, Pablo Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Tittonell, Pablo Adrian. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Tittonell, Pablo Adrian. Universite de Montpellier. Centre de cooperation Internationale en Recherche Agronomique pour le Developpement. Agroecologie et Intensification Durable; FranciaFil: Tittonell, Pablo Adrian. Groningen University. Groningen Institute of Evolutionary Life Sciences; HolandaFil: Fernandez, Manuela Teresa. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Fernandez, Manuela Teresa. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: El Mujtar, Veronica Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: El Mujtar, Veronica Andrea. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Viegas Preiss, Potira. University of Santa Cruz do Sul. Regional Development Posgraduate Program; BrasilFil: Sapura, Silvia. University of Guelph. School of Environmental Design and Rural Development; CanadaFil: Laborda, Luciana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Laborda, Luciana. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Mendonça, M.A. Federal University of Viçosa; BrasilFil: Alvarez, Valeria Esther. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Alvarez, Valeria Esther. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Fernandes, G.B. Centro de Tecnologias Alternativas da Zona da Mata; BrasilFil: Petersen, Paulo F. AS-PTA Agricultura Familiar e Agroecologia; BrasilFil: Cardoso, Irene María. Federal University of Viçosa; Brasi
Beyond CO<sub>2</sub>:Multiple ecosystem services from ecologically intensive grazing landscapes of South America
Full text linkSustainability assessments to inform the design of multifunctional grazing landscapes need to look beyond greenhouse gas emissions to simultaneously embrace other social and environmental criteria. Here I briefly examine trade-offs and synergies between the productivity of graze-based livestock systems and the environment, and share a few generic guidelines to design pathways for the ecological intensification of livestock systems following agroecological principles. I draw from experience on livestock farming in the Rio de la Plata Grassland Biome of South America (Argentina, Uruguay, and Brazil). Livestock systems based on native grasslands in this region may have greater carbon footprints (13–29 kg CO2 eq. kg LW−1) than intensive grass-feedlot systems in the region (9–14 kg CO2 eq. kg LW−1) or the average range reported for OECD countries (c. 10–20 kg CO2 eq. kg LW−1) when calculated per unit product, but only 20% greater when expressed on an area basis. Yet they use less external energy (10x) or nitrogen inputs (5x) per kg live weight (LW) produced, provide ecosystem services of local and global importance, such as carbon storage, habitat protection for biodiversity, watershed regulation, clean water, food and textiles, livelihoods and local cultures, and provide better living conditions for grazing animals. Traditional graze-based systems are less economically attractive than intensive livestock or grain production and they are being replaced by such activities, with negative social and environmental consequences. An ecological intensification (EI) of graze-based livestock systems is urgently needed to ensure economic profits while minimising social-ecological trade-offs on multifunctional landscapes. Examples of such EI systems exist in the region that exhibit synergies between economic and environmental goals, but a broad and lasting transition towards sustainable multifunctional landscapes based on agroecological principles requires (co-)innovation at both technical and institutional levels.</p
Convergence between satellite information and farmers’ perception of drought in rangelands of North-West Patagonia, Argentina
Full text linkDrought is a complex natural hazard with social and environmental implications. Satellite information is increasingly used to support decision-makers in preventing or coping with the negative impacts of drought. The integration of local and scientific knowledge to support drought monitoring is still far from being the main procedure in the development of drought monitoring and early warning systems. This study aimed at assessing the degree of convergence between satellite information on the effect of droughts on rangeland vegetation, from time series analysis, and farmers’ perception of drought in North-West Patagonia, Argentina. We characterised the scientific evidence of drought in terms of duration, spatial distribution, most severe years and recovery for the period 2000–2018 by identifying inter-annual NDVI changes. Farmers’ perceptions and experiences of drought were studied with open-ending interviews, with respect to occurrence, duration and recovery for that period. Satellite information matched farmers’ perception of drought at a regional scale, emphasising the value of remote sensing tools in supporting regional policy decision-making. However, farmers’ perceptions and recall of past drought impacts were more diverse than satellite information at a local level, highlighting the need for knowledge integration at finer scales.Estación Experimental Agropecuaria BarilocheFil: Solano-Hernández, Ainhoa. Wageningen University. Farming Systems Ecology; HolandaFil: Bruzzone, Octavio Augusto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Groot, Jeroen C. J. Wageningen University & Research. Farming Systems Ecology Group, Plant Sciences; HolandaFil: Laborda, Luciana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Martinez, Abel Hector Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Agencia de Extensión Rural Zapala; ArgentinaFil: Tittonell, Pablo Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentina. Wageningen University & Research. Farming Systems Ecology Group, Plant Sciences; Holanda. Université de Montpellier. Centre de coopération Internationale en Recherche Agronomique pour le Développement (CIRAD). Agroécologie et Intensification Durable; FranciaFil: Easdale, Marcos Horacio. Instituto Nacional de Tecnologia Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área Desarrollo Rural; Argentin
Urban, periurban and horticultural landscapes:Conflict and sustainable planning in La Plata district, Argentina
Full text linkGlobally, urban areas are expanding onto high-quality agricultural soils and natural environments reducing the area available for food production. The Horticultural Belt of La Plata is one of the main horticultural areas in South America. It is a productive territory that lacks clear spatial planning, resulting in serious socio-environmental problems. Our main objectives were to quantify areas with different land-use aptitude across the region, and to identify areas of potential land-use conflict, detecting those areas that should be prioritized in the development of landscape planning policies. We implement the analytical hierarchy process multicriteria analysis method and a weighted linear combination procedure of factors standardization. We observed a strong influence of urbanization in determining land use in those areas where high/very high aptitude for urbanization and for horticulture overlap. Competition for land use between open field horticulture and greenhouses was observed too. Our research reveals the market influence and the current trend towards intensification of land use that usually prevails in planning strategies. We identified elements that could take part of a multifunctional network of green spaces, made them spatially explicit, and defined a core area for the protection of horticultural production. Finally, we propose recommendations for territorial planning aimed at improving the conditions for the development of more sustainable productive landscapes, a problem that predominates across the world.</p
Strengthening understanding and perceptions of mineral fertilizer use among smallholder farmers: evidence from collective trials in western Kenya
No full textIt is widely recognized that mineral fertilizers must play an important part in improving agricultural productivity in western Kenyan farming systems. This paper suggests that for this goal to be realized, farmers’ knowledge must be strengthened to improve their understanding of fertilizers and their use. We analyzed smallholder knowledge of fertilizers and nutrient management, and draw practical lessons from empirical collective fertilizer-response experiments. Data were gathered from the collective fertilizer-response trials, through focus group discussions, by participant observation, and via in-depth interviews representing 40 households. The collective trials showed that the application of nitrogen (N) or phosphorous (P) alone was insufficient to enhance yields in the study area. The response to P on the trial plots was mainly influenced by incidences of the parasitic Striga weed, by spatial variability or gradients in soil fertility of the experimental plots, and by interactions with N levels. These results inspired farmer to design and conduct experiments to compare crop performance with and without fertilizer, and between types of fertilizers, or responses on different soils. Participating farmers were able to differentiate types of fertilizer, and understood rates of application and the roles of respective fertilizers in nutrient supply. However, notions were broadly generated by unsteady yield responses when fertilizers were used across different fertility gradients, association with high cost (especially if recommended rates were to be applied), association of fertilizer use with hybrids and certain crops, historical factors, among other main aspects. We identified that strengthening fertilizer knowledge must be tailored within existing, albeit imperfect, systems of crop and animal husbandry. Farmers’ perceptions cannot be changed by promoting more fertilizer use alone, but may require a more basic approach that, for example, encourages farmer experimentation and practices to enhance soil properties such as carbon build-up in impoverished local soils
Exploring drivers and levels of technology adoption for ecological intensification of pastoral systems in north Patagonia drylands
Full text linkAlthough pastoral systems make a significant contribution to food security, they are also pointed out as being responsible for substantial environmental impact. Ecological intensification through process- rather than input-based technologies has been proposed as a means to achieve economic, environmental, and social win-win situations. We studied structural diversity, technology adoption, farmer´s strategies, and functional attributes (productivity, reproductive efficiency, greenhouse gas emissions, diversification, and self-sufficiency) of pastoral systems in North Patagonia based on interviews of 70 farms with the following objectives: (a) to analyze farm structural characteristics as drivers of technology adoption for ecological intensification, (b) to describe their association with farmers´ livelihood strategies, and (c) to explore trade-offs and synergies among functional attributes. An ongoing ecological intensification was revealed based on the adoption of technologies towards animal´s welfare, survival, and overall systems´ efficiency, on-farm produced feed (self-sufficiency), and product diversification, promoting nutrient re-cycling within farm boundaries. Four farm types were differentiated by their access to information exchange channels, which together with labor characteristics determined technology adoption and farmers´ strategies. The main strategy of family farms that exhibited low to no hired labor, and intermediate to low access to information, was the diversification of products or incomes. Larger farms, with hired labor and access to information exchange channels, had an entrepreneurial strategy towards increasing production efficiencies. Enteric emission intensity per unit product and area exhibited significant trade-offs with meat production (Spearman ρ = 0.87; Y = 0.459 X + 0.352; R2 = 0.95), and synergies with reproduction efficiency (Spearman ρ = 0.51; Y = −0.013 X + 1.612; R2 = 0.28), respectively. Improving individual animal production instead of per unit area is encouraged to prevent overgrazing and land degradation, searching for win-win's between emission mitigation and livestock production.</p
Antimicrobial resistance dissemination associated with intensive animal production practices in Argentina: A systematic review and meta-analysis
Full text linkAbuse and misuse of antimicrobial agents has accelerated the spread of antimicrobial-resistant bacteria. The association between antimicrobial-resistant infections in humans and antimicrobial use in agriculture is complex, but well-documented. This study provides a systematic review and meta-analysis of the dissemination of antimicrobial resistance (AMR) to antimicrobials defined as critically important by the WHO, in swine, chicken, and cattle from intensive and extensive production systems in Argentina. We conducted searches in electronic databases (MEDLINE-PubMed, Web of Science, SciELO, the National System of Digital Repositories from Argentina) as well as in the gray literature. Inclusion criteria were epidemiological studies on AMR in the main food-transmitted bacteria, Salmonella spp., Campylobacter spp., Escherichia coli and Enterococcus spp., and mastitis-causing bacteria, isolated from swine, chicken, dairy and beef cattle from Argentina. This study gives evidence for supporting the hypothesis that AMR of common food-transmitted bacteria in Argentina is reaching alarming levels. Meta-analyses followed by subgroup analyses confirmed the association between the prevalence of AMR and (a) animal species (p<0.01) for streptomycin, ampicillin and tetracycline or (b) the animal production system (p<0.05) for streptomycin, cefotaxime, nalidixic acid, ampicillin and tetracycline. Moreover, swine (0.47 [0.29; 0.66]) and intensive production (0.62 [0.34; 0.83]) showed the highest pooled prevalence of multidrug resistance while dairy (0.056 [0.003; 0.524]) and extensive production (0.107 [0.043; 0.240]) showed the lowest. A research gap regarding beef-cattle from feedlot was identified. Finally, there is an urgent need for political measures meant to coordinate and harmonize AMR surveillance and regulate antimicrobial use in animal production
Back to the people : The role of community-based responses in shaping landscape trajectories in Oaxaca, Mexico
Full text linkLand use change results from top-down drivers, such as policies, trade, and migration. Land use change may also result from community-based responses. In Mexico, rural communities govern most of the country's forests. This study aimed to assess how socio-economic and biophysical factors affected the landscape trajectories of rural communities in southern Mexico. It also aimed at evaluating the role of communities in landscape change. Land use change of 63 rural communities was analyzed for the years 1987 and 2017. Four land uses were distinguished: forest, shrubland, agriculture, and bare soil. Five groups of communities were identified according to their socio-economic and biophysical factors. Two groups located in areas with high slopes and elevated marginalization index values showed deforestation patterns. Two other groups, consisting of more than half of the municipalities assessed, showed reforestation trends. The final group did not reveal major changes in land use. Two municipalities with reforestation trends were selected for an in-depth analysis of how community-based responses impacted natural resource management and conservation. Through local assemblies, the population voted for regulations that increased the forest area and reduced the bare soil. There was no evidence that these regulations affected croplands. These results show how a combination of socio-economic and biophysical factors can affect landscape change, but it also shows the often overlooked role of communities as a relevant bottom-up driver of change
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