The influence of geomagnetic flux on global crop yields and income

Most of the world's food is produced in a handful of countries, the so-called breadbaskets of the world. Due to climate change, there is an increasing risk of crop failures, due to compounding hot and dry extremes. Furthermore, certain climate drivers – through teleconnections – have shown to lead to simultaneous crop failures around the globe. This highlights the importance to understand which climate processes drive global crop yield variability. Here we show global crop yield failures (Maize, Soya, Wheat, Rice, and combined) are associated with La Nina-like sea surface temperature (SST) anomalies, using Archetype Analysis. The adverse crop-yield archetypes show simultaneous hot-dry-surface imprints across the world, highlighting these high risk crop failure scenarios are driven by climate extremes. Our results demonstrate the importance in understanding the climate drivers of global crop production, and highlights the deep uncertainty associated with a changing climate. The response of ENSO due to anthropogenic activities is not yet fully understood and climate models often inaccurately reproduce the observed La Nina trends. Thus the fact that our results indicate that simultaneous crop failures are linked to La Nina like SSTs, highlights the deep uncertainty we currently face regarding food security in the future.

Agricultral lands are facing with severe challenges from droughts in the context of global warming. Flash drought, in particular, may cause more severe impacts on crop yields given its rapid intensification process which leaves less time for drought preparation and mitigation. Moveover, the associated impacts can also be different depending on the hit timing of flash drought in different stages of crop phenology. Based on the fifth-generation of reanalysis (ERA5) soil moisutre data, global crop yields and crop phenology data, the impacts of flash droughts by considering crop phenology were evaluated. The results show that flash droughts became more frequent in global agricultural lands during 1940-2022. Moreover, the development of flash droughts became more rapid given the shoterned days of drought onset. More than half of flash droughts occurred during the critical growth preiod of crops when the water requirements are high to gurantee crop growth and yields. The results highlight the necessity of taking crop phenology into consideration for accurately estimating flash drought risks in agricultural lands.

Cheap and abundant nitrogen (N) fertilizer has driven revolutionary increases in global crop yields. However, N is susceptible to being lost from agricultural fields and transported into water bodies where, in excess, it contributes to drinking water contamination, harmful algal blooms, and hypoxia. This work investigates the potential to improve the Pareto front of crop yield and N loss outcomes through high-frequency, in-season soil sampling and fertilizer application. The current paradigm in agriculture is (1) to apply N either entirely before plant emergence or split between pre-plant and a single “side-dressing” after plant emergence and (2) to measure soil N concentrations yearly or less often. However, advances in agricultural field robotics and remote sensing are making it possible to attain and act on soil data more quickly and precisely and thus to maintain crop yield while decreasing N losses. To date though, few studies have attempted to describe optimal fertilizer strategies that make use of such high-frequency monitoring and actuation tools or how much N loss abatement these strategies could achieve. Indeed, such analysis is challenging due to the complex and high-dimensional nature of the N management problem.This study provides a model abstraction and discretization scheme that make dynamic programming (DP) for N management computationally feasible while maintaining decision-relevant features of the problem. The DP algorithm computes a strategy on incremental fertilizer application rates and timing based on the N and water content in the soil as well as weather predictions. The strategy is optimized for a maximum expected land profitability minus a fine that is incurred when N losses exceed a statutory threshold. By varying the level of the fine for N loss violations, we map the DP outcomes to a Pareto front that characterizes the maximum land profitability that can be achieved at different likelihoods of violating the N loss threshold. Finally, we compute multiple strategies via DP, each using different frequencies for soil monitoring and fertilizer application, and we show that increasing the frequency shifts the Pareto front toward improved (lower) likelihoods of N loss violation without sacrificing land profitability.

We estimate annual discontinuities in remotely-sensed crop yields at all international land borders and link them to changes in the economic freedom index by the Fraser Institute, a country-level measure of institutional quality.Each point of the ten-point index increases the discontinuity by 2.2% over the next five years, highlighting that institutional reforms have the potential to close some of the observed crop yield gap. Three subcategories are consistently significant: credit market regulation, inflation, and the top marginal tax rate.We present suggestive evidence that higher average yields are achieved through increased use of irrigation and mechanization.Yield variability remains unchanged, and reforms lead to cropland expansion through deforestation.

Synchronous crop failure among multiple breadbaskets worldwide, a typical spatially compound event, may amplify threats to the global food system and food security and has been a growing concern among the scientific community in recent years. While the risk of simultaneous crop loss across multiple breadbasket regions has been analyzed, to date, little is known about how interdependence among regional crop production affects aggregated crop failure at the global scale. Quantifying the impact of dependencies among breadbasket regions on global food production and assessing how the dynamic of spatially compounding crop failures is simulated by climate and crop models is essential for informing the modeling of global food security risk. In this study, focusing on different crop types, we quantify the influence of dependence between crop production of individual regions on global aggregated crop yield based on the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) dataset. We find that spatial dependence between regional crop yields may aggravate global crop deficits and identify a characteristic spatial scale beyond which the dependence between crop production in different regions vanishes. Our results provide valuable information for designing risk strategies for food security at the suited scale.

Statistical emulators of maize, rice, soybean and wheat yields from global gridded crop models

We present the output data of Robust Principal Component Analysis (RPCA) applied to global crop yield variability of maize, rice, sorghum and soybean (MRSS) as presented in the publication “Climate drives variability and joint variability of global crop yields” (Najafi et al., 2019). Global maps of the correlation between all the principal components (PCs) acquired from the low rank matrix (L) of MRSS and Palmer Drought Severity Index (PDSI), air temperature anomalies (ATa) and sea surface temperature anomalies (SSTa) are provided in this article. We present co-varying countries, impacted cropland areas across global countries, and 10 global regions by climate and the association between PCs and multiple atmospheric and oceanic indices. Moreover, the joint dependency between PCs of MRSS yields are presented using two different approaches.

Global crop yield has been affected by a number of abiotic stresses. Heat, salinity, and drought stress are at the top of the list as serious environmental growth-limiting factors. To enhance crop productivity, molecular approaches have been used to determine the key regulators affecting stress-related phenomena. MYB transcription factors (TF) have been reported as one of the promising defensive proteins against the unfavorable conditions that plants must face. Different roles of MYB TFs have been suggested such as regulation of cellular growth and differentiation, hormonal signaling, mediating abiotic stress responses, etc. To gain significant insights, a comprehensive in-silico analysis of OsMYB TF was carried out in comparison with 21 dicot MYB TFs and 10 monocot MYB TFs. Their chromosomal location, gene structure, protein domain, and motifs were analyzed. The phylogenetic relationship was also studied, which resulted in the classification of proteins into four basic groups: groups A, B, C, and D. The protein motif analysis identified several conserved sequences responsible for cellular activities. The gene structure analysis suggested that proteins that were present in the same class, showed similar intron-exon structures. Promoter analysis revealed major cis-acting elements that were found to be responsible for hormonal signaling and initiating a response to abiotic stress and light-induced mechanisms. The transformation of OsMYB TF into tobacco was carried out using the Agrobacterium-mediated transformation method, to further analyze the expression level of a gene in different plant parts, under stress conditions. To summarize, the current studies shed light on the evolution and role of OsMYB TF in plants. Future investigations should focus on elucidating the functional roles of MYB transcription factors in abiotic stress tolerance through targeted genetic modification and CRISPR/Cas9-mediated genome editing. The application of omics approaches and systems biology will be indispensable in delineating the regulatory networks orchestrated by MYB TFs, facilitating the development of crop genotypes with enhanced resilience to environmental stressors. Rigorous field validation of these genetically engineered or edited crops is imperative to ascertain their utility in promoting sustainable agricultural practices.

Rapid evolutionary dynamics of pepper mild mottle virus

Drought is the single abiotic stress with the biggest impact on global crop yields, thus improving crop performance under water-limiting conditions is essential to global food security. This chapter is intended to cover a broad overview of traits and mechanisms known to play a role in drought tolerance in crop plants. Although traditional breeding has largely focused on improving yield under stress-free conditions, a number of mechanisms exist that may be exploited to improve drought tolerance; these include the ABA signaling network for regulation of stomatal movements and root architecture modifications. This chapter reviews the biochemical and molecular modifications induced by water deficit. Stress-induced regulatory genes, specifically involved in marshaling survival responses in metabolism and development, are covered. Traits and genes from tolerant varieties, landraces, and wild relatives, known to contribute to drought tolerance from major crops are also addressed. As our understanding of signaling pathways improves based on studies in models, new traits and opportunities for genetic improvement emerge. Developing varieties that have high yields and are yield-stable in dry environments requires progress in both understanding and applying of genetic and physiological processes. This chapter covers the key traits and genes that have the greatest potential for improving drought tolerance in crop species.

A pollinator decline caused by environmental degradation might be compromising the production of pollinator-dependent crops. In a recent article, we compared 45 year series (1961–2006) in yield, production, and cultivated area of pollinator-dependent and nondependent crop around the world. If pollinator shortage is occurring globally, we expected a lower annual growth rate in yield for pollinator-dependent than nondependent crops, but a higher growth in cultivated area to compensate the lower yield. We have found little evidence for the first “yield” prediction but strong evidence for the second “area” prediction. Here, we present an additional analysis to show that the first and second predictions are both supported for crops that vary in dependency levels from nondependent to moderate dependence (i.e. up to 65% average yield reduction without pollinators). However, those crops for which animal pollination is essential (i.e. 95% average yield reduction without pollinators) showed higher growth in yield and lower expansion in area than expected in a pollination shortage scenario. We propose that pollination management for highly pollinator-dependent crops, such us renting hives or hand pollination, might have compensated for pollinator limitation of yield.

BackgroundFuture impacts of rising temperatures and extreme weather events on agriculture are expected to be severe, potentially resulting in a 25% reduction in global crop yields by 2050. As a risk multiplier, global warming also exacerbates existing conflicts over natural resources. In the event of large-scale conflicts like nuclear war, food production could suffer significantly, potentially declining by 90% in global average calorie production due to the resulting cold and dark weather conditions. Lemnaceae (commonly known as ‘duckweed’) is a family of prolific aquatic plants and a high-protein food source. It is capable of growing in extreme hot or cold conditions, where conventional crops struggle. This study investigates the effects of both global warming and post-nuclear war cooling on duckweed growing seasons and biomass production. A plant growth model was coupled with climate data to predict annual duckweed yields across 20 locations worldwide, considering two global warming scenarios: (1) an optimistic sustainable pathway with low greenhouse gas emissions and (2) a fossil fuel-dominated pathway with medium to high greenhouse gas emissions. We also examined three post-nuclear war cases with different atmospheric carbon injections.ResultsIn low-latitude equatorial regions, global warming and the low-emission nuclear war case had minimal impact on duckweed yields (less than 6% change from baseline), whereas higher latitudes experienced yield increases (up to 90%) with global warming. The high-emission nuclear war cases showed a significant reduction in yields, but equatorial regions could still produce 19–20 metric ton/ha of duckweed annually.ConclusionsThe findings from this work substantiate the versatility of duckweed to improve global food security under both global warming and post-catastrophic cooling scenarios.

The Green Revolution of the 1960s brought about a dramatic rise in global crop yields. But, as most observers acknowledge, this has come at a considerable cost to biodiversity. Plant breeding, synthetic fertilizers, and mechanization steadily narrowed the number of crop varieties commercially available to farmers and promoted fencerow-to-fencerow monocultures. Many historians trace the origins of this style of industrialized agriculture to the last great plow-up of the Great Plains in the 1920s. In the literature, farms in the plains are often described metaphorically as wheat factories, degrading successive landscapes. While in many ways these farms were a departure from earlier forms of husbandry in the American experience, monocultures were quite rare during the early transformation of the plains. Analysis of a large representative sample, based on manuscript agricultural censuses and involving twenty-five townships across the state of Kansas, demonstrates that diverse production reached even the most challenging of plains landscapes.

Little is known about the multiple impacts of sustainable land management practices on soil and water conservation, carbon sequestration, mitigation of global change and crop yield productivity in semiarid Mediterranean agroecosystems. We hypothesized that a shift from intensive tillage to more conservative tillage management practices (reduced tillage optionally combined with green manure) leads to an improvement in soil structure and quality and will reduce soil erosion and enhance carbon sequestration in semiarid Mediterranean rainfed agroecosystems. To test the hypothesis, we assessed the effects of different tillage treatments (conventional (CT), reduced (RT), reduced tillage combined with green manure (RTG), and no tillage (NT)) on soil structure and soil water content, runoff and erosion control, soil carbon dioxide (CO2) emissions, crop yield and carbon sequestration in two semiarid agroecosystems with organic rainfed almond (Prunus dulcis Mill) in the Murcia Region (southeast Spain). It was found that reduction and suppression of tillage under almonds led to an increase in soil water content in both agroecosystems. Crop yields ranged from 775 to 1,766 kg ha−1 between tillage treatments, but we did not find a clear relation between soil water content and crop yield. RT and RTG treatments showed lower soil erosion rates and higher crop yields of almonds than under CT treatment. Overall, higher soil organic carbon contents and aggregate stability were observed under RTG treatment than under RT or CT treatment. It is concluded that conversion from CT to RTG is suitable to increase carbon inputs without enhancing soil CO2 emissions in semiarid Mediterranean agroecosystems.

Urban expansion often occurs on croplands. However, there is little scientific understanding of how global patterns of future urban expansion will affect the world's cultivated areas. Here, we combine spatially explicit projections of urban expansion with datasets on global croplands and crop yields. Our results show that urban expansion will result in a 1.8-2.4% loss of global croplands by 2030, with substantial regional disparities. About 80% of global cropland loss from urban expansion will take place in Asia and Africa. In both Asia and Africa, much of the cropland that will be lost is more than twice as productive as national averages. Asia will experience the highest absolute loss in cropland, whereas African countries will experience the highest percentage loss of cropland. Globally, the croplands that are likely to be lost were responsible for 3-4% of worldwide crop production in 2000. Urban expansion is expected to take place on cropland that is 1.77 times more productive than the global average. The loss of cropland is likely to be accompanied by other sustainability risks and threatens livelihoods, with diverging characteristics for different megaurban regions. Governance of urban area expansion thus emerges as a key area for securing livelihoods in the agrarian economies of the Global South.