Information about the global structure of agriculture and nutrient production and its diversity is essential to improve present understanding of national food production patterns, agricultural ...livelihoods, and food chains, and their linkages to land use and their associated ecosystems services. Here we provide a plausible breakdown of global agricultural and nutrient production by farm size, and also study the associations between farm size, agricultural diversity, and nutrient production. This analysis is crucial to design interventions that might be appropriately targeted to promote healthy diets and ecosystems in the face of population growth, urbanisation, and climate change.
We used existing spatially-explicit global datasets to estimate the production levels of 41 major crops, seven livestock, and 14 aquaculture and fish products. From overall production estimates, we estimated the production of vitamin A, vitamin B12, folate, iron, zinc, calcium, calories, and protein. We also estimated the relative contribution of farms of different sizes to the production of different agricultural commodities and associated nutrients, as well as how the diversity of food production based on the number of different products grown per geographic pixel and distribution of products within this pixel (Shannon diversity index H) changes with different farm sizes.
Globally, small and medium farms (≤50 ha) produce 51–77% of nearly all commodities and nutrients examined here. However, important regional differences exist. Large farms (>50 ha) dominate production in North America, South America, and Australia and New Zealand. In these regions, large farms contribute between 75% and 100% of all cereal, livestock, and fruit production, and the pattern is similar for other commodity groups. By contrast, small farms (≤20 ha) produce more than 75% of most food commodities in sub-Saharan Africa, southeast Asia, south Asia, and China. In Europe, west Asia and north Africa, and central America, medium-size farms (20–50 ha) also contribute substantially to the production of most food commodities. Very small farms (≤2 ha) are important and have local significance in sub-Saharan Africa, southeast Asia, and south Asia, where they contribute to about 30% of most food commodities. The majority of vegetables (81%), roots and tubers (72%), pulses (67%), fruits (66%), fish and livestock products (60%), and cereals (56%) are produced in diverse landscapes (H>1·5). Similarly, the majority of global micronutrients (53–81%) and protein (57%) are also produced in more diverse agricultural landscapes (H>1·5). By contrast, the majority of sugar (73%) and oil crops (57%) are produced in less diverse ones (H≤1·5), which also account for the majority of global calorie production (56%). The diversity of agricultural and nutrient production diminishes as farm size increases. However, areas of the world with higher agricultural diversity produce more nutrients, irrespective of farm size.
Our results show that farm size and diversity of agricultural production vary substantially across regions and are key structural determinants of food and nutrient production that need to be considered in plans to meet social, economic, and environmental targets. At the global level, both small and large farms have key roles in food and nutrition security. Efforts to maintain production diversity as farm sizes increase seem to be necessary to maintain the production of diverse nutrients and viable, multifunctional, sustainable landscapes.
Commonwealth Scientific and Industrial Research Organisation, Bill & Melinda Gates Foundation, CGIAR Research Programs on Climate Change, Agriculture and Food Security and on Agriculture for Nutrition and Health funded by the CGIAR Fund Council, Daniel and Nina Carasso Foundation, European Union, International Fund for Agricultural Development, Australian Research Council, National Science Foundation, Gordon and Betty Moore Foundation, and Joint Programming Initiative on Agriculture, Food Security and Climate Change—Belmont Forum.
•We model farming systems evolution in the Kenyan highlands.•We link socio-economic scenarios with regional and household models.•Intensification, diversification and stagnation can occur ...simultaneously in a region.•Socio-political conditions modify the opportunity costs of resource use in farming systems.•Multi-scale models and scenarios useful for linking global change and local scale processes.
We explore how smallholder agricultural systems in the Kenyan highlands might intensify and/or diversify in the future under a range of socio-economic scenarios. Data from approximately 3000 households were analyzed and farming systems characterized. Plausible socio-economic scenarios of how Kenya might evolve, and their potential impacts on the agricultural sector, were developed with a range of stakeholders. We study how different types of farming systems might increase or diminish in importance under different scenarios using a land-use model sensitive to prices, opportunity cost of land and labour, and other variables. We then use a household model to determine the types of enterprises in which different types of households might engage under different socio-economic conditions. Trajectories of intensification, diversification, and stagnation for different farming systems are identified. Diversification with cash crops is found to be a key intensification strategy as farm size decreases and labour costs increase. Dairy expansion, while important for some trajectories, is mostly viable when land available is not a constraint, mainly due to the need for planting fodders at the expense of cropland areas. We discuss the results in relation to induced innovation theories of intensification. We outline how the methodology employed could be used for integrating global and regional change assessments with local-level studies on farming options, adaptation to global change, and upscaling of social, environmental and economic impacts of agricultural development investments and interventions.
Land cover change has always had a central role in land change science. This central role is largely the result of the possibilities to map and characterize land cover based on observations and ...remote sensing. This paper argues that more attention should be given to land use and land functions and linkages between these. Consideration of land functions that provide a wide range of goods and services makes more integrated assessments of land change possible. The increasing attention to multifunctional land use is another incentive to develop methods to assess changes in land functions. A number of methods to quantify and map the spatial extent of land use and land functions are discussed and the implications for modeling are identified based on recent model approaches in land change science. The mixed use of land cover, land use and land function in maps and models leads to inconsistencies in land change assessments. Explicit attention to the non-linear relations between land cover, land use and land function is essential to consistently address land change. New methods to map and quantify land function dynamics will enhance our ability to understand and model land system change and adequately inform policies and planning.
Livestock are the major consumers of water but also sustain millions of pastoralist and farming families. In regions where water is a scarce commodity, such as the Nile basin, there is a need for ...strategies to improve livestock water productivity (LWP). This study seeks to contribute to this need through a better understanding of livestock water use and productivity within the Nile basin and how this varies across the basin. We developed a spatial framework combining dynamic models of digestion in ruminants, crop water requirements (CWRs), and animal drinking water requirements to estimate spatial distribution of livestock water requirements in different livestock production systems (LPSs). We compared this with livestock production and water availability estimates within the basin. The results show that in most areas LWP is less than 0.1 USD/m³, with only few areas showing a LWP of 0.5 USD/m³ and higher. This is largely related to very low livestock meat and milk production on one hand and very variable, but, in general, low feed water productivity (fWP). Total water need for feed production was estimated to be roughly 94 billion m³, which amounts to approximately 5% of the total annual rainfall (68 billion m³ or 3.6% of total annual rainfall when excluding water for residues). Differences in LWP between systems and regions are large, suggesting considerable scope for improvements. We discuss the main factors influencing observed patterns of LWP and livestock water use and how this information can be used for developing strategies for increasing the water productivity of agricultural systems at the basin level.
During the past 20 years, most settlements of the Brazilian Agrarian Reform (AR) have been established in or near better-preserved natural ecosystems, where environmental impact is likely to be ...negative and contribute to natural resources degradation. The objective of this work is providing a first, comprehensive insight of the impacts related to the environmental quality of these settlements, based on the primary survey of 4,340 AR settlements installed between 1985 and 2001. An index was calculated to integrate different aspects of environmental impacts in one single number. The index showed significant regional variation, with lower values (low environmental quality) for the North and Northeast of Brazil, intermediate values for the Central-west and Southeast, and high values for the South. Environmental impacts resulting from AR and settlement creation are slowly decreasing with time, but are still very high in absolute values. The lack of protection of riparian areas, cultivation of legal reserves, and deforestation, are the main concerns related to environmental impacts.
Até o presente a maioria dos assentamentos da Reforma Agrária brasileira (AR) têm sido estabelecidos em ou perto de ambientes preservados, nos quais impactos ambientais negativos são esperados e podem levar à degradação dos recursos naturais. O objetivo deste trabalho foi apresentar uma visão ampla dos impactos relacionados à qualidade ambiental dos assentamentos com base em dados primários coletados em 4.340 projetos criados entre 1985 e 2001. Um índice foi criado com a finalidade de integrar diferentes aspectos ambientais. Este índice apresentou expressiva variação regional, com valores menores (baixa qualidade ambiental) nas regiões Norte e Nordeste do Brasil, intermediários na região Centro-Oeste e Sudeste, e elevados na região Sul. Os impactos ambientais resultantes da criação de assentamentos diminuíram com o tempo, mas ainda são elevados em termos absolutos. A falta de proteção de Áreas de Preservação Permanente, o cultivo de Reservas Legais e o desmatamento são os principais fatores relacionados aos impactos ambientais.
Provider: - Institution: - Data provided by Europeana Collections- Zugl.: Braunschweig, Univ., Diss., 2003- All metadata published by Europeana are available free of restriction under the Creative ...Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
The objective of this report is to provide an assessment of the impact of climate change and variability on the agriculture sector and economy of Kenya as an initial task to devise adaptation ...strategies for smallholders in selected agro-ecological zones of the country.
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