RESUMO

In this research, we build two food systems datasets in Mexico; The first one describes the structure of agricultural production units and the second one describes food security aspects of the rural population in these agricultural production units. We also build a third dataset, consisting of path diagrams and path coefficients (derived from Structural Equation Modeling) that relate the first dataset to the second dataset in the four most populated ecoregions of Mexico. The description of the path models and the insights they bring to the current state of food security in Mexican rural households are detailed in an associated article entitled "Is food security primarily associated with smallholder agriculture or with commercial agriculture?: An approach to the case of Mexico using structural equation modeling" (https://doi.org/10.1016/j.agsy.2021.103091). The agricultural variables (in the first dataset) include farm size, destination of the farmer's production, cultivation practice / water management, predominant source of income of the household, land tenure type, crop diversity, agricultural surface expansion, and the presence of forest cover. They are based on the primary data of the full, latest available agricultural census in Mexico and corresponding official land use / land cover data. The second dataset consists of four food security indicators designed and built for the first food security model in Mexico that incorporates food availability, food accessibility and food utilization aspects. They include the Food Self-sufficiency Index (the balance between food production and food consumption), the Food Access Index (inversely related to marginalization), the Entitlement to Public Health Care index, and the Undernutrition Infrequency index (related to hospital sickness records). We provide the path tables and diagrams that describe the links between the agricultural structure and food security. These diagrams provide the first nationwide statistical evidence for the prominent role of smallholder agriculture in rural food security at the national level and at ecoregion scale for a country of the global South. In order to further investigate the structure of the agricultural production units and their relationships with socio-economic, territorial and landscape data, artificial intelligence (i.e. data mining and machine learning) techniques could be performed on this compendium of datasets. The food security data may stir the development of more food security models in Mexico in relation to other drivers such as consumption habits and non-agricultural activities of rural households.

RESUMO

Young breeding programs in developing countries, like the Chibas sorghum breeding program in Haiti, face the challenge of increasing genetic gain with limited resources. Implementing genomic selection (GS) could increase genetic gain, but optimization of GS is needed to account for these programs' unique challenges and advantages. Here, we used simulations to identify conditions under which genomic-assisted recurrent selection (GARS) would be more effective than phenotypic recurrent selection (PRS) in small new breeding programs. We compared genetic gain, cost per unit gain, genetic variance, and prediction accuracy of GARS (two or three cycles per year) vs. PRS (one cycle per year) assuming various breeding population sizes and trait genetic architectures. For oligogenic architecture, the maximum relative genetic gain advantage of GARS over PRS was 12-88%, which was observed only during the first few cycles. For the polygenic architecture, GARS provided maximum relative genetic gain advantage of 26-165%, and was always superior to PRS. Average prediction accuracy declines substantially after several cycles of selection, suggesting the prediction models should be updated regularly. Updating prediction models every year increased the genetic gain by up to 33-39% compared to no-update scenarios. For small populations and oligogenic traits, cost per unit gain was lower in PRS than GARS. However, with larger populations and polygenic traits cost per unit gain was up to 67% lower in GARS than PRS. Collectively, the simulations suggest that GARS could increase the genetic gain in small young breeding programs by accelerating the breeding cycles and enabling evaluation of larger populations.

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RESUMO

Agroforestry management in smallholder agriculture can provide climate change mitigation and adaptation benefits and has been promoted as 'climate-smart agriculture' (CSA), yet has generally been left out of international and voluntary carbon (C) mitigation agreements. A key reason for this omission is the cost and uncertainty of monitoring C at the farm scale in heterogeneous smallholder landscapes. A largely overlooked alternative is to monitor C at more aggregated scales and develop C contracts with groups of land owners, community organizations or C aggregators working across entire landscapes (e.g., watersheds, communities, municipalities, etc.). In this study we use a 100-km2 agricultural area in El Salvador to demonstrate how high-spatial resolution optical satellite imagery can be used to map aboveground woody biomass (AGWB) C at the landscape scale with very low uncertainty (95% probability of a deviation of less than 1%). Uncertainty of AGWB-C estimates remained low (<5%) for areas as small as 250 ha, despite high uncertainties at the farm and plot scale (34-99%). We estimate that CSA adoption could more than double AGWB-C stocks on agricultural lands in the study area, and that utilizing AGWB-C maps to target denuded areas could increase C gains per unit area by 46%. The potential value of C credits under a plausible adoption scenario would range from $38,270 to $354,000 yr-1 for the study area, or about $13 to $124 ha-1 yr-1, depending on C prices. Considering farm sizes in smallholder landscapes rarely exceed 1-2 ha, relying solely on direct C payments to farmers may not lead to widespread CSA adoption, especially if farm-scale monitoring is required. Instead, landscape-scale approaches to C contracting, supported by satellite-based monitoring methods such as ours, could be a key strategy to reduce costs and uncertainty of C monitoring in heterogeneous smallholder landscapes, thereby incentivizing more widespread CSA adoption.

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RESUMO

No Nordeste Paraense alguns agricultores familiares têm implantado pequenas áreas de pastagens e manejado pequenos rebanhos com o objetivo de aplicar eventuais ganhos obtidos com os cultivos, criando uma poupança a ser utilizada nas necessidades futuras da família ou da propriedade. Há indícios de problemas nas pastagens e no rebanho que limitam tanto a produção e a sustentabilidade da pecuária, como comprometem os cultivos agrícolas que realmente sustentam a propriedade. Este estudo tratou de identificar as principais limitações e propor alternativas de manejo que sejam econômica e ecologicamente mais sustentáveis. Na primeira fase do estudo, numa amostra ao acaso de 38 propriedades, descreveu-se o manejo da pastagem e do rebanho, e na segunda, numa amostra menor, de doze propriedades e por um período de 29 meses, avaliou-se o potencial desses dois componentes. As propriedades estudadas desenvolvem uma pecuária de baixa produtividade. Devido à baixa fertilidade do solo e o deficiente manejo, as pastagens não suprem os alimentos necessários ao rebanho, tanto em quantidade como em qualidade. Também foram identificadas deficiências no manejo do rebanho, próprias de sistemas extensivos. Contudo, as limitações podem ser solucionadas com práticas amplamente conhecidas de manejo da pastagem (como formação, manutenção e manejo) e do rebanho (reprodução, manejo de bezerros e sanidade em geral). Novos modelos de exploração também foram sugeridos.

In Northeastern Pará, smallholder agriculturalists have established small pastures and manage small herds, mainly with the objective of investing profits in their crops, as a form of savings to meet the family's and property's future needs. There are indications of pasture and herd problems that limit production and sustainability, and threaten the crops that really sustain the property. This study sought to identify constraints and technological solutions, and make information available for public policies. In the 1st phase of this study and using 38 smallholdings sampled at random, the pastures and herd management were described, and in the 2nd phase, with a smaller sample of 12 smallholdings during 29-month period, the potential of these two components was evaluated. In general, the smallholdings have low-productivity and ranching is vulnerable. Due to the low soil fertility and the deficient management, pastures do not supply all the herd's feed needs, neither in quantity nor quality. Herd management deficiencies are characteristic of extensive production systems. However, these constraints can be overcome with well-known technologies of pasture establishment, maintenance and management, and herd reproduction, calf management, and herd health, allowing significant improvement. New exploitation models were suggested also.

Assuntos

RESUMO

In Northeastern Pará, smallholder agriculturalists have established small pastures and manage small herds, mainly with the objective of investing profits in their crops, as a form of savings to meet the family's and property's future needs. There are indications of pasture and herd problems that limit production and sustainability, and threaten the crops that really sustain the property. This study sought to identify constraints and technological solutions, and make information available for public policies. In the 1st phase of this study and using 38 smallholdings sampled at random, the pastures and herd management were described, and in the 2nd phase, with a smaller sample of 12 smallholdings during 29-month period, the potential of these two components was evaluated. In general, the smallholdings have low-productivity and ranching is vulnerable. Due to the low soil fertility and the deficient management, pastures do not supply all the herd's feed needs, neither in quantity nor quality. Herd management deficiencies are characteristic of extensive production systems. However, these constraints can be overcome with well-known technologies of pasture establishment, maintenance and management, and herd reproduction, calf management, and herd health, allowing significant improvement. New exploitation models were suggested also.

No Nordeste Paraense alguns agricultores familiares têm implantado pequenas áreas de pastagens e manejado pequenos rebanhos com o objetivo de aplicar eventuais ganhos obtidos com os cultivos, criando uma poupança a ser utilizada nas necessidades futuras da família ou da propriedade. Há indícios de problemas nas pastagens e no rebanho que limitam tanto a produção e a sustentabilidade da pecuária, como comprometem os cultivos agrícolas que realmente sustentam a propriedade. Este estudo tratou de identificar as principais limitações e propor alternativas de manejo que sejam econômica e ecologicamente mais sustentáveis. Na primeira fase do estudo, numa amostra ao acaso de 38 propriedades, descreveu-se o manejo da pastagem e do rebanho, e na segunda, numa amostra menor, de doze propriedades e por um período de 29 meses, avaliou-se o potencial desses dois componentes. As propriedades estudadas desenvolvem uma pecuária de baixa produtividade. Devido à baixa fertilidade do solo e o deficiente manejo, as pastagens não suprem os alimentos necessários ao rebanho, tanto em quantidade como em qualidade. Também foram identificadas deficiências no manejo do rebanho, próprias de sistemas extensivos. Contudo, as limitações podem ser solucionadas com práticas amplamente conhecidas de manejo da pastagem (como formação, manutenção e manejo) e do rebanho (reprodução, manejo de bezerros e sanidade em geral). Novos modelos de exploração também foram sugeridos.

RESUMO

Este trabalho objetivou avaliar os Sistemas Agroflorestais-SAF comerciais multiestratificados de agricultores familiares de Igarapé-Açu, bem como identificar as espécies que compõem os sistemas agroflorestais. A partir de entrevistas foram catalogadas as espécies de maior interesse dos agricultores familiares e por meio de inventário florístico foram avaliados os SAF produtivos. Os cultivos de pimenta-do-reino, mandioca, feijão, cupuaçu, caju, açaí, pupunha, mogno e o nim indiano foram os mais freqüentes pelos agricultores. Os SAF são manejados na sua maioria de forma tradicional.

This paper aimed to evaluate the multistrata agroforestry systems of small farmers of Igarapé-Açu, as well as to identify the species that compose of they interest. Through interviews were listed the interest species of small farmers and from inventory floristic were evaluated the productive AFS. The species: pepper-of-kingdom, cassava, beans, cupuaçu, caju, açai palm, pupunha palm, mahogany and indian neem were the most cultivated by these farmers. Most of the AFS are managed in the traditional manner.

Assuntos

RESUMO

This paper aimed to evaluate the multistrata agroforestry systems of small farmers of Igarapé-Açu, as well as to identify the species that compose of they interest. Through interviews were listed the interest species of small farmers and from inventory floristic were evaluated the productive AFS. The species: pepper-of-kingdom, cassava, beans, cupuaçu, caju, açai palm, pupunha palm, mahogany and indian neem were the most cultivated by these farmers. Most of the AFS are managed in the traditional manner.

Este trabalho objetivou avaliar os Sistemas Agroflorestais-SAF comerciais multiestratificados de agricultores familiares de Igarapé-Açu, bem como identificar as espécies que compõem os sistemas agroflorestais. A partir de entrevistas foram catalogadas as espécies de maior interesse dos agricultores familiares e por meio de inventário florístico foram avaliados os SAF produtivos. Os cultivos de pimenta-do-reino, mandioca, feijão, cupuaçu, caju, açaí, pupunha, mogno e o nim indiano foram os mais freqüentes pelos agricultores. Os SAF são manejados na sua maioria de forma tradicional.