Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title><jats:p>Achieving food security remains a pressing challenge for small-scale farmers, especially in sub-Saharan Africa and Latin America. Ongoing climate change, invasive noxious weeds, and crop pests further exacerbate the situation. Optimizing traditional cropping systems for sustainable yields and climate-resilient production is imperative in order to address this challenge. The pre-Columbian <jats:italic>milpa</jats:italic> system of intercropping maize with companion crops such as beans (<jats:italic>Phaseolus vulgaris</jats:italic>) and squash (<jats:italic>Cucurbita</jats:italic> spp.) is one effective system that has been shown to produce outstanding yields per unit area compared to monoculture systems. The Push-Pull Technology developed in East Africa, based on the use of repellent and trap companion plants intercropped with maize (and to a lesser extent sorghum), is seen to be similarly effective in minimizing the impact of major pests on yields, including striga weed (<jats:italic>Striga</jats:italic> spp.), maize stemborers, and the fall armyworm (<jats:italic>Spodoptera frugiperda</jats:italic>). Although both systems have the potential to compensate for each other’s limitations, there has been no cross-system learning between the Mesoamerican <jats:italic>milpa</jats:italic> and the East African Push-Pull Technology. Here, we review both systems and present the advantages likely to be obtained by combining these technologies in small-scale farming. The proposed <jats:italic>milpa push-pull</jats:italic> system could adapt to different gradients of altitude, rainfall, and soil nutrient levels, in addition to controlling pests, and therefore has the potential to become a fundamental cropping technique in Latin America and sub-Saharan Africa.</jats:p>

<jats:title>Abstract</jats:title><jats:p> This virtual issue comprises papers that address diversification for providing sustainable solutions at different scales from cropping and grassland to food systems. The authors investigated processes in case studies at the landscape scale where synergies and trade-offs between social and environmental objectives become the most tangible. Contributions from all continents highlighted regional specificities related to diversification and include research from natural and social sciences, with inter- and transdisciplinary approaches including synthesis of knowledge (reviews), empirical studies with experiments as well as assessments with interviews in case studies: Model-based design of crop diversification, the role of digitalization for achieving sustainability in the European context, ecological engineering for rice pest suppression in China, the role of cereal species mixtures in Ethiopian smallholder farmers, diversified planting in arid irrigation areas in northwestern China, integration of legumes in European and Canadian cropping systems, screening of native forage legumes for northern Swedish grassland systems, cropping system diversification of smallholder farmers in south-central Bangladesh, identification of how farmers imagine diversified landscapes in southern Idaho in the US, farm diversification affecting impacts from COVID-19 across Europe, the role of diversified farming in Mato Grosso Brazil, diversification and soil management measures in Germany, value chain formation for the scaling of crop diversification, and the design process with farmers and scientists for the transition toward legume-supported farming in Europe. A key finding from these examples is that agricultural intensification has led to the simplification of cropping systems and landscapes in terms of species diversity and ecosystem function. To instead move towards sustainable transformation, all system levels (i.e. from the plot, farm, landscape, governance and overall food systems) need to interact and reinforce each other for diversification to deliver the desired outcomes.</jats:p>

<jats:title>Abstract</jats:title><jats:p>A major effect of environment on crops is through crop phenology, and therefore, the capacity to predict phenology for new environments is important. Mechanistic crop models are a major tool for such predictions, but calibration of crop phenology models is difficult and there is no consensus on the best approach. We propose an original, detailed approach for calibration of such models, which we refer to as a calibration protocol. The protocol covers all the steps in the calibration workflow, namely choice of default parameter values, choice of objective function, choice of parameters to estimate from the data, calculation of optimal parameter values, and diagnostics. The major innovation is in the choice of which parameters to estimate from the data, which combines expert knowledge and data-based model selection. First, almost additive parameters are identified and estimated. This should make bias (average difference between observed and simulated values) nearly zero. These are “obligatory” parameters, that will definitely be estimated. Then candidate parameters are identified, which are parameters likely to explain the remaining discrepancies between simulated and observed values. A candidate is only added to the list of parameters to estimate if it leads to a reduction in BIC (Bayesian Information Criterion), which is a model selection criterion. A second original aspect of the protocol is the specification of documentation for each stage of the protocol. The protocol was applied by 19 modeling teams to three data sets for wheat phenology. All teams first calibrated their model using their “usual” calibration approach, so it was possible to compare usual and protocol calibration. Evaluation of prediction error was based on data from sites and years not represented in the training data. Compared to usual calibration, calibration following the new protocol reduced the variability between modeling teams by 22% and reduced prediction error by 11%.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Agriculture faces potentially competing societal demands to produce food, fiber and fuel while reducing negative environmental impacts and delivering regulating, supporting and cultural ecosystem services. This necessitates a new generation of long-term agricultural field experiments designed to study the behavior of contrasting cropping systems in terms of multiple outcomes. We document the principles and practices of a new long-term experiment of this type at Rothamsted, established at two contrasting sites in 2017 and 2018, and report initial yield data at the crop and system level. The objective of the Large-Scale Rotation Experiment was to establish gradients of system properties and outcomes to improve our fundamental understanding of UK cropping systems. It is composed of four management factors—phased rotations, cultivation (conventional vs reduced tillage), nutrition (additional organic amendment vs standard mineral fertilization) and crop protection (conventional vs smart crop protection). These factors were combined in a balanced design resulting in 24 emergent cropping systems at each site and can be analyzed at the level of the system or component management factors. We observed interactions between management factors and with the environment on crop yields, justifying the systems level, multi-site approach. Reduced tillage resulted in lower wheat yields but the effect varied with rotation, previous-crop and site. Organic amendments significantly increased spring barley yield by 8% on average though the effect again varied with site. The plowed cropping systems tended to produce higher caloric yield overall than systems under reduced tillage. Additional response variables are being monitored to study synergies and trade-offs with outcomes other than yield at the cropping system level. The experiment has been established as a long-term resource for inter-disciplinary research. By documenting the design process, we aim to facilitate the adoption of similar approaches to system-scale agricultural experimentation to inform the transition to more sustainable cropping systems.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Perennial crops replacing annual crops are drawing global attention because they harbor potential for sustainable biomass production and climate change mitigation through soil carbon sequestration. At present, it remains unclear how long perennial crops can sequester carbon in the soil and how soil carbon stock dynamics are influenced by climate, soil, and plant properties across the globe. This study presents a meta-analysis synthesizing 51 publications (351 observations at 77 sites) distributed over different pedo-climatic conditions to scrutinize the effect of perennialization on organic carbon accumulation in soil compared with two annual benchmark systems (i.e., monoculture and crop rotation). Results showed that perennial crops significantly increased soil organic carbon stock by 16.6% and 23.1% at 0–30 cm depth compared with monoculture and crop rotation, respectively. Shortly after establishment (&lt; 5 years), perennial crops revealed a negative impact on soil organic carbon stock; however, long duration (&gt; 10 years) of perennialization had a significant positive effect on soil organic carbon stock by 30% and 36.4% at 0–30 cm depth compared with monoculture and crop rotation, respectively. Compared with both annual systems, perennial crops significantly increased soil organic carbon stock regardless of their functional photosynthetic types (C<jats:sub>3</jats:sub>, C<jats:sub>4</jats:sub>, or C<jats:sub>3</jats:sub>-C<jats:sub>4</jats:sub> intermediates) and vegetation type (woody or herbaceous). Among other factors, pH had a significant impact on soil organic carbon; however, the effect of soil textures showed no significant impact, possibly due to a lack of observations from each textural class and mixed pedoclimatic effects. Results also showed that time effect of perennialization revealed a sigmoidal increase of soil organic carbon stock until about 20 years; thereafter, the soil carbon stocks advanced towards a steady-state level. In conclusion, perennial crops increased soil organic carbon stock compared with annual systems; however, the time since conversion from annual to perennial system decisively impacted soil organic carbon stock changes.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Herd health management is a critical issue for the future of dairy systems. The right combination of preventive and curative practices will depend on management system, level of work productivity, and self-sufficiency objectives, and will entail specific skills and work organizations. However, the combination of work dimensions and animal health management has rarely been explored in the literature on a livestock farming system scale. The <jats:italic>Grand Ouest</jats:italic> region of France spans a diverse array of livestock farming systems that can serve to design herd health management indicators, farming objectives and work arrangements, and explore their linkages. Here we ran semi-structured interviews on 10 dairy farms, analyzed the farmers’ discourses, and built 7 variables and 25 modalities that, for the first time, cover three components, namely herd health, farming objectives and work arrangements, and we tested various associations between these variables. Our interview data confirms that consultants and veterinarians have a key role to play in building a pool of skills adapted to various types of health management system. Data suggests linkages between prevention measures, alternative or conventional curative interventions, and work-related parameters.</jats:p>