Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title><jats:p>There is a lack of data on resources used and food produced at urban farms. This hampers attempts to quantify the environmental impacts of urban agriculture or craft policies for sustainable food production in cities. To address this gap, we used a citizen science approach to collect data from 72 urban agriculture sites, representing three types of spaces (urban farms, collective gardens, individual gardens), in five countries (France, Germany, Poland, United Kingdom, and United States). We answered three key questions about urban agriculture with this unprecedented dataset: (1) What are its land, water, nutrient, and energy demands? (2) How productive is it relative to conventional agriculture and across types of farms? and (3) What are its contributions to local biodiversity? We found that participant farms used dozens of inputs, most of which were organic (e.g., manure for fertilizers). Farms required on average 71.6 L of irrigation water, 5.5 L of compost, and 0.53 m<jats:sup>2</jats:sup> of land per kilogram of harvested food. Irrigation was lower in individual gardens and higher in sites using drip irrigation. While extremely variable, yields at well-managed urban farms can exceed those of conventional counterparts. Although farm type did not predict yield, our cluster analysis demonstrated that individually managed leisure gardens had lower yields than other farms and gardens. Farms in our sample contributed significantly to local biodiversity, with an average of 20 different crops per farm not including ornamental plants. Aside from clarifying important trends in resource use at urban farms using a robust and open dataset, this study also raises numerous questions about how crop selection and growing practices influence the environmental impacts of growing food in cities. We conclude with a research agenda to tackle these and other pressing questions on resource use at urban farms.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Soil degradation threatens agricultural production and soil multifunctionality. Efforts for private and public governance are increasingly emerging to leverage sustainable soil management. They require consensus across science, policy, and practice about what sustainable soil management entails. Such agreement does not yet exist to a sufficient extent in agronomic terms; what is lacking is a concise list of soil management measures that enjoy broad support among all stakeholders, and evidence on the question what hampers their implementation by farmers. We therefore screened stakeholder documents from public governance institutions, nongovernmental organizations, the agricultural industry, and conventional and organic farmer associations for recommendations related to agricultural soil management in Germany. Out of 46 recommended measures in total, we compiled a shortlist of the seven most consensual ones: (1) structural landscape elements, (2) organic fertilization, (3) diversified crop rotation, (4) permanent soil cover, (5) conservation tillage, (6) reduced soil loads, and (7) optimized timing of wheeling. Together, these measures support all agricultural soil functions, and address all major soil threats except soil contamination. Implementation barriers were identified with the aid of an online survey among farmers (<jats:italic>n</jats:italic> = 78). Results showed that a vast majority of farmers (&gt; 80%) approved of all measures. Barriers were mostly considered to be economic and in some cases technological, while missing knowledge or other factors were less relevant. Barriers were stronger for those measures that cannot be implemented in isolation, but require a systemic diversification of the production system. This is especially the case for measures that are simultaneously beneficial to many soil functions (measures 2, 3, and 4). Results confirm the need for a diversification of the agricultural system in order to meet challenges of food security and climate change. The shortlist presents the first integrative compilation of sustainable soil management measures supporting the design of effective public or private governance.</jats:p>

<jats:title>Abstract</jats:title><jats:p>There is an urgent need for agri-food system transformation to achieve global sustainability goals. Innovations can play a key role in this transformation but often come with both sustainability synergies and trade-offs. One such innovation is agricultural mechanization, which is spreading rapidly in parts of the Global South and is high on the policy agenda in others. The rapid spread of mechanization is fundamentally changing the character of agri-food systems in the Global South, with both positive and negative effects. However, while some of these effects have been well explored, no study so far has systematically reviewed the sustainability synergies and trade-offs associated with mechanization, undermining necessary accompanying research and policy efforts. This review provides an overview of the progress toward mechanization across the Global South, identifies drivers and barriers, assesses sustainability synergies and trade-offs, and discusses options to maximize sustainability outcomes. The review is the first to holistically assess the potentials and risks of agricultural mechanization for the sustainable transformation of agri-food systems in the Global South, taking into account all pillars of sustainability. The review suggests that agricultural mechanization is needed to make agri-food systems more sustainable concerning various economic and social aspects, such as labor productivity, poverty reduction, food security, and health and well-being. However, there are also sustainability risks concerning environmental aspects such as biodiversity loss and land degradation, and economic and social concerns related to lacking inclusiveness and growing inequalities, among others. A wide range of technological and institutional solutions is identified to harness the potential of agricultural mechanization for sustainable agri-food system transformation, while at the same time minimizing the risks. However, more efforts are needed to implement such solutions at scale and ensure that mechanization contributes to agri-food systems that respect all pillars of sustainability.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Sorghum is an important food and feed crop in the dry lowland areas of Ethiopia. Farmers grow both early-sown long-duration landraces and late-sown short-duration improved varieties. Because timing and intensity of drought stress can vary in space and time, an understanding of major traits (G), environments (E), management (M), and their interactions (G×E×M) is needed to optimize grain and forage yield given the limited available resources. Crop simulation modeling can provide insights into these complex G×E×M interactions and be used to identify possible avenues for adaptation to prevalent drought patterns in Ethiopia. In a previous study predictive phenology models were developed for a range of Ethiopian germplasm. In this study, the aims were to (1) further parameterize and validate the APSIM-sorghum model for crop growth and yield of Ethiopian germplasm, and (2) quantify by simulation the productivity-risk trade-offs associated with early vs late sowing strategies in the dry lowlands of Ethiopia. Field experiments involving Ethiopian germplasm with contrasting phenology and height were conducted under well-watered (Melkassa) and water-limited (Miesso) conditions and crop development, growth and yield measured. Soil characterization and weather records at the experimental sites, combined with model parameterization, enabled testing of the APSIM-sorghum model, which showed good correspondence between simulated and observed data. The simulated productivity for the Ethiopian dry lowlands environments showed trade-offs between biomass and grain yield for early and late sowing strategies. The late sowing strategy tended to produce less biomass except in poor seasons, whereas it tended to produce greater grain yield except in very good seasons. This study exemplified the systems approach to identifying traits and management options needed to quantify the production-risk trade-offs associated with crop adaptation in the Ethiopian dry lowlands and further exemplifies the general robustness of the sorghum model in APSIM for this task.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Factors affecting fertilizer decisions made by grain growers are changing in the context of changing climatic conditions and growing volatility in global fertilizer and grain markets. To ensure sustainable development of grain industries in light of this uncertainty, research, development, extension, and adoption activities associated with growers’ fertilizer decisions need to be focused on factors to which they are most sensitive. The aim of this paper is to understand the factors that have the greatest influence on grain producer’s fertilizer strategies, how these factors have changed over recent years, and what is the relative importance of agronomic, socioeconomic, and logistical factors affecting these strategies. A telephone survey of 425 grain-growing businesses in Western Australia was conducted, and survey results were analyzed statistically. We show for the first time that grain growers’ fertilizer decisions are most sensitive to agronomic factors (especially the amount and distribution of rainfall). Logistic factors (such as difficulties fertilizing increasing areas in short periods of time) are growing in influence as farm size, cropping areas, and the number of fertilizer applications within seasons increase. Fertilizer decisions have become less sensitive to socioeconomic factors over the last 10 to 15 years. To ensure sustainable development of grain production, research through to adoption activities should focus on agronomic issues (such as seasonal forecasting) and logistic issues (such as improving planning, organizational, and technical capacity for developing and implementing fertilizer strategies).</jats:p>

<jats:title>Abstract</jats:title><jats:p>Significant detrimental effects of agricultural intensification and specialization are becoming increasingly evident. Reliance on monocultures, few varieties, and intensive use of agrochemicals is a major factor in climate change, biodiversity decline, soil health deterioration, and pollution, putting our food system at risk. This requires sustainable agricultural processes, such as crop diversification, to be more rapidly and effectively tested, adopted, and scaled. While these processes are typically introduced at niche level, they often struggle to scale and to induce broader sustainability transitions. In this study, we investigate how scaling may occur, focusing on institutional logics, their changes, and realignment over time. In particular, we applied an abductive research strategy to collect empirical evidence from two in-depth, longitudinal case studies of innovation niches related to crop diversification. Doing so, we show for the first time that, despite their many differences, scaling processes of crop diversification in both niches converge, presenting similar progressions in terms of institutional dimensions, and facing similar obstacles when it comes to value chain formation. While initial experimentation could still be implemented using organizational forms familiar to the lead actors, we discover that a systemic lack of adequate value chain arrangements obstructed the scaling process of crop diversification in both cases. These findings have been used to reflect on the role of value chain relations in scaling processes in sustainability transitions in agriculture.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Maize production in Zambia must increase with a view towards improved food security and reduced food imports whilst avoiding cropland expansion. To achieve this, it is important to understand the causes behind the large maize yield gaps observed in smallholder farming systems across the country. This is the first study providing a yield gap decomposition for maize in Zambia, and combining it with farm typology delineation, to identify the key limiting factors to maize yield gaps across the diversity of farms in the country. The analysis builds upon a nationally representative household survey covering three growing seasons and crop model simulations to benchmark on-farm maize yields and N application rates. Three farm types were delineated, including households for which maize is a marginal crop, households who are net buyers of maize, and households who are market-oriented maize producers. Yield gap closure was about 20% of the water-limited yield, corresponding to an actual yield of 2.4 t ha<jats:sup>− 1</jats:sup>. Market-oriented maize farms yielded slightly more than the other farm types, yet the drivers of yield variability were largely consistent across farm types. The large yield gap was mostly attributed to the technology yield gap indicating that more efficient production methods are needed to raise maize yields beyond the levels observed in highest yielding fields. Yet, narrowing efficiency and resource yield gaps through improved crop management (i.e., sowing time, plant population, fertilizer inputs, and weed control) could more than double current yields. Creating a conducive environment to increase maize production should focus on the dissemination of technologies that conserve soil moisture in semi-arid areas and improve soil health in humid areas. Recommendations of sustainable intensification practices need to consider profitability, risk, and other non-information constraints to improved crop management and must be geographically targeted to the diversity of farming systems across the country.</jats:p>

<jats:title>Abstract</jats:title><jats:p>In the future, a cropping system that guarantees food security by delivering high yields and, simultaneously, protects our environment is desperately needed. This can be achieved through a cropping system that waives chemical synthetic plant protection products, which endanger, for example, biodiversity and water resources. However, such a system, referred to here as the mineral-ecological cropping system (MECS), should still allow for the usage of mineral fertilizers to ensure high yields. It can be thought of as a compromise between the current conventional and organic cropping systems. This article presents a comprehensive literature review on the economic, social, and environmental effects of pesticides and the resulting reasons farmers have to use (or not use) them. Hereby, regarding future pesticide reduction, we identify hindrances and potential benefits that could be mobilized to design the MECS. The major points are the following: in a MECS, (1) it is expected that yields and temporal stability of yields will be higher than in organic farming, but lower than in conventional farming; (2) profitability might suffer due to high input costs and energy consumption; (3) it is expected that soil fertility and biodiversity protection will increase along with the promotion of alternative disease and pest control measures; (4) crop rotations will be wider and more diverse than in conventional farming; (5) mineral fertilizer cannot be optimally used by the crops unless a balanced supply of nitrogen is achieved. Farmers who want to switch to MECS should be compensated as they are likely to experience higher costs and lower yield and yield stability. The lessons learned from this review will help to progress toward an innovative and sustainable cropping system. Further research should focus on rational farmers’ adaptation possibilities when abandoning pesticides while still using mineral fertilizers.</jats:p>