Review of agronomic research on the milpa, the traditional polyculture system of Mesoamerica

The milpa system is the basis of traditional agriculture in Mesoamerica. It is based on a polyculture of maize (Zea mays L.), bean (Phaseolus spp.) and squash (Cucurbita spp.) and is associated with a great diversity of crops and wild species. The milpa has great cultural and historical importance but can also be highly productive and provide sufficient and healthy diets for smallholder farmers. The milpa system is practiced less and less however, mainly due to socioeconomic changes, but also due to a lack of agronomic knowledge adapted to current conditions. To provide a starting point for new agronomic research, we reviewed the scientific literature to identify the current knowledge on milpa agronomy and determine research priorities to further improve the system. Given the wide diversity of conditions under which milpa is practiced, agronomic research is lacking, but indicates that improvements to the milpa can be made in all aspects of the milpa. 176 research articles on the milpa system were found in databases, of which 61 treated agronomic research. The main agronomic topics described in literature are crop variety, soil fertility management, weed management and productivity. Most research has focused only on maize and studies reporting on the associated crops are scarce. More research on all aspects of the milpa is needed to understand and improve the agronomy of the system under the changing conditions of modern agriculture. Reducing the workload associated with the milpa, as well as soil fertility and weed management can be identified as research priorities

Insights in the global genetics and gut microbiome of black soldier fly, Hermetia illucens: implications for animal feed safety control

Open Access Journal; Published online: 07 July 2020The utilization of the black soldier fly (BSF) Hermetia illucens L. for recycling organic waste into high-quality protein and fat biomass for animal feeds has gained momentum worldwide. However, information on the genetic diversity and environmental implications on safety of the larvae is limited. This study delineates genetic variability and unravels gut microbiome complex of wild-collected and domesticated BSF populations from six continents using mitochondrial COI gene and 16S metagenomics. All sequences generated from the study linked to H. illucens accessions KM967419.1, FJ794355.1, FJ794361.1, FJ794367.1, KC192965.1, and KY817115.1 from GenBank. Phylogenetic analyses of the sequences generated from the study and rooted by GenBank accessions of Hermetia albitarsis Fabricius and Hermetia sexmaculata Macquart separated all samples into three branches, with H. illucens and H. sexmaculata being closely related. Genetic distances between H. illucens samples from the study and GenBank accessions of H. illucens ranged between 0.0091 and 0.0407 while H. sexmaculata and H. albitarsis samples clearly separated from all H. illucens by distances of 0.1745 and 0.1903, respectively. Genetic distance matrix was used to generate a principal coordinate plot that further confirmed the phylogenetic clustering. Haplotype network map demonstrated that Australia, United States 1 (Rhode Island), United States 2 (Colorado), Kenya, and China shared a haplotype, while Uganda shared a haplotype with GenBank accession KC192965 BSF from United States. All other samples analyzed had individual haplotypes. Out of 481,695 reads analyzed from 16S metagenomics, four bacterial families (Enterobactereaceae, Dysgonomonadaceae, Wohlfahrtiimonadaceae, and Enterococcaceae) were most abundant in the BSF samples. Alpha-diversity, as assessed by Shannon index, showed that the Kenyan and Thailand populations had the highest and lowest microbe diversity, respectively; while microbial diversity assessed through Bray Curtis distance showed United States 3 (Maysville) and Netherlands populations to be the most dissimilar. Our findings on genetic diversity revealed slight phylogeographic variation between BSF populations across the globe. The 16S data depicted larval gut bacterial families with economically important genera that might pose health risks to both animals and humans. This study recommends pre-treatment of feedstocks and postharvest measures of the harvested BSF larvae to minimize risk of pathogen contamination along the insect-based feed value chain

Climate security in the Central American Dry Corridor

The evidence on conflicts around the world since the turn of the century points to a simple conclusion: conflicts, grievances and insecurities are increasingly being affected by changing climates, environmental degradation, food insecurity, and the struggle to control a finite pool of natural resources. This paper aims to understand the linkages between climate, conflict, agriculture, and migration in the Central American Dry Corridor and offer a road map for the region while emphasizing the role of research and development. We do this by first clarifying what climate security means and how it links to risk and resilience (introduction). We then present causal impact pathways to describe how climate exacerbates drivers of conflict and insecurity (Section 1). We continue with a social media and policy coherence analysis to explain how the linkages between climate and conflict are perceived by the public (Section 2) and represented in public policies (Section 3). We then describe the linkages between climate and security for Honduras, El Salvador and Guatemala (Section 4). This is followed by an overview of indicators summarizing the state of climate security in Central America and the Dry Corridor and a discussion of the limitations of such indicators (Section 5). We then present existing research for development efforts and discuss their potential to contribute to climate security by mitigating its drivers (Section 6). We offer entry points for improving climate security in the Central American Dry Corridor (Section 7) and finally, Section 8 proposes entry points for incorporating climate security dimensions into rural development and regional and national security policy and research agendas

Infrasound as a cue for seabird navigation

Seabirds are amongst the most mobile of all animal species and spend large amounts of their lives at sea. They cross vast areas of ocean that appear superficially featureless, and our understanding of the mechanisms that they use for navigation remains incomplete, especially in terms of available cues. In particular, several large-scale navigational tasks, such as homing across thousands of kilometers to breeding sites, are not fully explained by visual, olfactory or magnetic stimuli. Low-frequency inaudible sound, i.e., infrasound, is ubiquitous in the marine environment. The spatio-temporal consistency of some components of the infrasonic wavefield, and the sensitivity of certain bird species to infrasonic stimuli, suggests that infrasound may provide additional cues for seabirds to navigate, but this remains untested. Here, we propose a framework to explore the importance of infrasound for navigation. We present key concepts regarding the physics of infrasound and review the physiological mechanisms through which infrasound may be detected and used. Next, we propose three hypotheses detailing how seabirds could use information provided by different infrasound sources for navigation as an acoustic beacon, landmark, or gradient. Finally, we reflect on strengths and limitations of our proposed hypotheses, and discuss several directions for future work. In particular, we suggest that hypotheses may be best tested by combining conceptual models of navigation with empirical data on seabird movements and in-situ infrasound measurements

One CGIAR and the Integrated Agri-food Systems Initiative: From short-termism to transformation of the world’s food systems

Agri-food systems are besieged by malnutrition, yield gaps, and climate vulnerability, but integrated, research-based responses in public policy, agricultural, value chains, and finance are constrained by short-termism and zero sum thinking. As they respond to current and emerging agri-food system challenges, decision makers need new tools that steer toward multi-sector, evidence-based collaboration. To support national agri-food system policy processes, the Integrated Agri-food System Initiative (IASI) methodology was devel oped and validated through case studies in Mexico and Colombia. This holistic, multi-sector methodology builds on diverse existing data resources and leverages situation analysis, modeled predictions, and scenarios to synchronize public and private action at the national level toward sustainable, equitable, and inclusive agri-food systems. Culminating in collec tively agreed strategies and multi-partner tactical plans, the IASI methodology enabled a multi-level systems approach by mobilizing design thinking to foster mindset shifts and stakeholder consensus on sustainable and scalable innovations that respond to real-time dynamics in complex agri-food systems. To build capacity for these types of integrated, con text-specific approaches, greater investment is needed in supportive international institu tions that function as trusted in-region ‘innovation brokers.’ This paper calls for a structured global network to advance adaptation and evolution of essential tools like the IASI methodol ogy in support of the One CGIAR mandate and in service of positive agri-food systems transformation