To face the social, ecological and productive vulnerability in the Pampa biome, it is important to unite production and environmental conservation to improve the quality of life of settled families. The general objective of the present study is to analyze, using the Nexus food-waterenergy approach, the reality of the settled families of the agrarian reform in the Pampa biome, covered by the Sustainable Backyards Project, and to evaluate the potential of agroforestry backyards in improving soil quality. This thesis is structured in the form of chapters. In chapter 1, the main strengths and limitations of settlements in the Pampa were evaluated in terms of food, water and energy security. The study covered the 1755 families contemplated by the Sustainable Backyards Project and from the SIGRA database (Integrated Rural Management System of ATES), 27 indicators were selected. In terms of food security, four indicators were present in more than 70% of the families: raising poultry, grain production, raising pigs and cattle for milk production. Family production focuses on animal husbandry, as evidenced by the correlation between poultry and pig farming. In agricultural crops, grain production (78%) and polycultures (37%) stood out. Water security indicators were present in less than 40% and the highest correlation was established between the presence of rivers/streams and springs. In energy security, the highest representation was established between the presence of electrification and single-phase type in more than 98%. The objective of chapter 2 is to evaluate soil quality under different agroforestry backyards in settlements in the municipalities of Júlio de Castilhos (area A) and Piratini (area B). The physical and chemical attributes showed differences between the sampled areas. The areas of agroforestry backyards and crops differed more intensely from the forest in terms of physical attributes related to soil porosity, when considering soil use in general. In similar areas, the physical and chemical variables were sensitive to soil use and management, considering the history of each piece of land. The results generated in this thesis demonstrate that settled families have an intermediate level of food, water and energy security, highlighting the need for research and promotion of public policies to improve the quality of life of families. In addition, the agroforestry backyards promoted improvements in the physical and chemical properties of the soil in the short term, due to the conservationist management practices carried out by the majority of the families, being recommended the accomplishment of studies and monitoring in the long term. | Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES | Para enfrentar a vulnerabilidade social, ecológica e produtiva no bioma Pampa, é importante unir produção e conservação ambiental para melhorar a qualidade de vida das famílias assentadas. O objetivo geral do presente estudo é analisar com a abordagem Nexus alimentoágua-energia, a realidade das famílias assentadas da reforma agrária no bioma Pampa, contempladas pelo Projeto Quintais Sustentáveis e avaliar o potencial dos quintais agroflorestais em melhorar a qualidade do solo. A presente tese está estruturada em forma de capítulos. No capítulo 1, foram avaliadas as principais potencialidades e limitações nos assentamentos no Pampa quanto a segurança alimentar, hídrica e energética. O estudo abrangeu as 1755 famílias contempladas pelo Projeto Quintais Sustentáveis e a partir do banco de dados do SIGRA (Sistema Integrado de Gestão Rural da ATES), foram selecionados 27 indicadores. Na segurança alimentar, quatro indicadores estiveram presentes em mais de 70% das famílias: criação de aves, produção de grãos, criação de suínos e bovinos para produção de leite. A produção familiar se concentra na criação animal, evidenciada pela correlação entre a criação de aves e a criação de suínos. Nos cultivos agrícolas, se destacou a produção de grãos (78%) e policultivos (37%). Os indicadores de segurança hídrica estiveram presentes em menos de 40% e a maior correlação se estabeleceu entre a presença de rios/riachos e nascentes. Na segurança energética, a maior representação se estabeleceu entre a presença de eletrificação e tipo monofásico em mais de 98%. O objetivo do capítulo 2, é avaliar a qualidade do solo sob diferentes quintais agroflorestais nos assentamentos nos municípios de Júlio de Castilhos (área A) e Piratini (área B). Os atributos físicos e químicos mostraram diferenças entre as áreas amostradas. As áreas de quintais agroflorestais e lavouras se distinguiram da mata mais intensamente quanto aos atributos físicos relacionados a porosidade do solo, quando considerado o uso do solo de forma geral. Em áreas semelhantes, as variáveis físicas e químicas foram sensíveis ao uso e manejo do solo, considerando o histórico de cada gleba. Os resultados gerados nesta tese, demonstram que as famílias assentadas apresentam um nível intermediário de segurança alimentar, hídrica e energética, evidenciando a necessidade de pesquisas e fomento às políticas públicas para melhorar a qualidade de vida das famílias. Além disso, os quintais agroflorestais promoveram melhorias nas propriedades físicas e químicas do solo a curto prazo, devido às práticas de manejo conservacionistas realizadas pela maioria das famílias, sendo recomendável a realização de estudos e monitoramento a longo prazo.

For more than a century, agricultural mechanization encouraged larger fields with more uniform management and increasing impacts on the environment. The trajectory of agricultural technology is now at an inflection point where information technology, including remote sensing, simulation modeling, decision support systems, precision agricultural technologies, and automation, enables site-specific management at small spatial scales with the potential to simultaneously enhance food and bioenergy production, farm profitability, and environmental quality. To achieve these economic and environmental benefits of transforming agricultural landscape design and cropping system management, agricultural producers need increased access to both enabling technologies and engineering expertise. Government policies and programs are also needed to incentivize changes in cropping systems that promote soil health and improve water quality, for example, payments to cover much or all of the cost of transitioning land use to perennials and nutrient trading programs in which agricultural producers contract with industrial and municipal wastewater generators to reduce nutrient loading at a reduced cost. Information technology is providing the tools to target, quantify, and document this re-coupling of economic, environmental, and social sustainability in food–energy–water systems.

This paper attempts to understand and explore the problem of eutrophication in the context of agriculture with the help of a nexus perspective. Eutrophication is significantly linked to water and energy resources with theoretically well-defined trade-offs and threshold levels. While looking at the linkages between water and land resources comprehensively, our paper questions the present approach to designing and implementing watershed management, and analyses the effects of agricultural intensification, especially in dry regions. Eutrophication is the process by which excessive nutrient loads in water bodies lead to undesirable water-quality problems and the degradation of the overall aquatic ecosystem. Due to limited information and knowledge on water and soil quality in most countries, farmers continue to use fertilizers at an increasing rate and agricultural run-off has been carrying ever more nitrogen and phosphorus into water bodies. This is likely to become a vicious cycle of eutrophication affecting food and water security. Of late, soil- and water-conservation interventions, like watershed development, are further reducing run-off. It is argued that there is a need to rethink the assumptions under which watershed interventions are designed and implemented.

Rapid intensification of Vietnamese rice production has had a positive effect on the nation's food production and economy. However, the sustainability of intensive rice production is increasingly being questioned within Vietnam, particularly in major agricultural provinces such as An Giang. The construction of high dykes within this province, which allow for complete regulation of water onto rice fields, has enabled farmers to grow up to three rice crops per year. However, the profitability of producing three crops is rapidly decreasing as farmers increase their use of chemical fertilizer inputs and pesticides. Increased fertilizer inputs are partly used to replace natural flood-borne, nutrient-rich sediment inputs that have been inhibited by the dykes, but farmers believe that despite this, soil health within the dyke system is degrading. However, the effects of the dykes on soil properties have not been tested. Therefore, a sampling campaign was conducted to assess differences in soil properties caused by the construction of dykes. The results show that, under present fertilization practices, although dykes may inhibit flood-borne sediments, this does not lead to a systematic reduction in nutrients that typically limit rice growth within areas producing three crops per year. Concentrations of total nitrogen, available phosphorous, and both total and available potassium, and pH were higher in the surface layer of soils of three crop areas when compared to two crop areas. This suggests that yield declines may be caused by other factors related to the construction of dykes and the use of chemical inputs, and that care should be taken when attempting to maintain crop yields. Attempting to compensate for yield declines by increasing fertilizer inputs may ultimately have negative effects on yields.

We used Cyprus as a model to link the Water–Energy–Food–Climate (WEFC) nexus indicators (e.g., carbon and water footprints) to the ecosystem services (ES) provided by 39 mixed orchards (stone fruits and nuts) on organic (Org) and conventional (Conv) farms. Food provision was lower for Org than Conv orchards. Management practices in Org mixed orchards better support climate change mitigation and water flow regulation. Soil quality parameters (e.g., organic matter and soil respiration), Arbuscular Mycorrhizal Fungi (AMF), and farm attributes (e.g., tree age) were significantly correlated to the GHG emissions per Mcal of food. Using cluster analysis, orchards were grouped based on WEFC indicators. Finally, a simple approach was developed to allow a rapid link between the WEFC and ES and to support decision making related to land use. This approach highlighted that in the case of Mediterranean mixed orchards, the main objective towards sustainability should be the balance between input management, food production, and ES from agroecosystems, rather than solely the attainment of high yields.

Rice cultivation in the South Asian region of Eastern Gangetic Plains (EGP) is running out of water, labour, low productivity and profitability. In addition, this system of crop production often ignores CO2-equivalent greenhouse-gas emissions, which are often rather significant. Although a dominant food-producing region in Asia is becoming poor in crop production, crop management approaches based on conservation agriculture-based sustainable intensification (CASI) increase the crop yields and improve profitability while lowering the water, energy and labour requirements, as well as greenhouse-gas emissions. The use of CASI approaches in EGP region villages and districts enhances crop diversification and intensifies their production. It also facilitates employment opportunities and micro entrepreneurship in rural areas. In on-farm experiments traditional and improved approaches in rice-based cropping systems were compared. We discovered that CASI management approaches increased the crop yields by 10%, reduced labour demand by 50% and increased water and energy productivity by 19% and 26% respectively. Overall, these findings showed that using CASI lowered crop production costs by up to 22% and raised gross margins by 12–32% compared with traditional methods. CASI management also resulted in CO2-equivalent emissions that were between 10% and 17% lower than those with traditional management. Initially, this principal research was collaborated on with farmer support groups for further extension. To encourage CASI adoption and out-scaling on a scale outside of research domains, an actively supporting policy environment was required.