Trade-offs associated with changing cropping patterns in semi-arid areas of Morocco

We developed a model-based framework to support land-use and management decision-making. This framework integrates data and models to support an assessment of scenarios related to crop choices and irrigation management. The framework includes the IPCC models to describe nutrient losses, the Rothamsted carbon model to predict soil organic carbon and Cornel's Environmental Impact Quotient model to predict impacts from pesticides (fungicides, herbicides and insecticides). We used Monte Carlo simulations to quantify model uncertainties. Shaded arrays were used to communicate the uncertainties to end users of the framework. We parameterised our framework to explore outcomes for an irrigated agricultural area in a semi-arid region of Morocco. We used the framework to explore scenarios that were codesigned with farming stakeholders. The scenarios related to crop diversification, and to recent policies on the expansion of olive cultivation and the adoption of efficient irrigation technologies. For the outcomes considered (production, profitability, soil carbon, nutrient losses, pesticide impacts), there were clear trade-offs associated with the cropping system choice. Compared to the baseline scenario of rotated crops, olive production led to greater carbon sequestration (average 4 % increase by doubling olive production), reduced water use (average 3 % reduction by doubling olive production), and reduced emissions (average 42 % reduction by doubling olive production) but was less profitable and provided fewer edible calories. Additionally, olive cultivation was associated with higher environmental impacts from pesticides. Diversified systems, while less profitable, were associated with less harmful pesticide use. Drip irrigation was associated with positive outcomes for profit (average 23 % increase), water use (average 13 % reduction in water use), and reduced nitrogen leaching (average 40 % reduction) with negligible changes in other metrics. However, we did not account for factors associated with increased groundwater depletion. We conclude that such frameworks are a useful means for policy-stakeholders to explore the outcomes of their decisions, thereby, helping to minimise unintended consequences

Biomass burning smoke pollution stimulates painted lady butterflies (Vanessa cardui L.) to increase flight speed

Smoke from biomass burning significantly degrades air quality due to high concentrations of particulate matter (PM2.5) and trace gases. While the ecological and health impacts of smoke pollution are well documented, its effects on insect migration remain poorly understood. In this study, we conducted two experiments to investigate the flight performance of Vanessa cardui butterflies under varying smoke conditions and identify the mechanisms influencing their behaviour. Butterflies were tethered to flight mills (TFMs) for 6 h, during which flight speed, distance, and duration were recorded across clean-air conditions and three levels of PM2.5 concentrations. Statistical analysis revealed that flight speed increases significantly as smoke concentration increases, although the increased range decreases. At a mean PM2.5 concentration of 120 μg m−3, flight speed increased by 52 % compared to clean-air conditions. To determine whether particulate matter was driving this response, individuals were exposed to smoke with and without particulates. In smoke with particulates retained, butterflies exhibited nearly double the flight speed compared to filtered smoke, indicating that particulates play a key role in altering flight behaviour. Scanning electron microscopy revealed significant deposition of smoke particulates on the antennae and abdomen, suggesting a sensory or physical response triggering accelerated flight. We interpret these findings as evidence that Vanessa cardui accelerates flight in smoky environments as an escape response. This study highlights the remarkable sensitivity of butterflies to smoke pollution and provides novel insights into the ecological consequences of biomass burning, particularly its potential impacts on insect behaviour and migration dynamics

Variation in suppression of black-grass by modern and ancestral cereal root exudates

This study aimed to determine the variability of hexaploid wheat Triticum aestivum, ancestral diploid wheat T. monococcum, and rye Secale cereale root exudates, in their potential to inhibit the arable weed black-grass Alopecurus myosuroides, informed by precedent for variability in resistance to herbivorous pests and pathogens across this cereal germplasm. As benzoxazinoids are suggested to play a role in resistance against these stressors, and also in allelopathy, we also aimed to identify these compounds in collected root exudates. We conducted in vitro and glasshouse bioassays to determine the efficacy of a wide range of crude cereal root exudates and their constituent compounds in inhibiting black-grass in both axenic and biologically-active media. LC-MS analysis was used to characterise the constituents of these exudates and their differences between hexaploid wheat, diploid wheat and rye. Root development of black-grass was suppressed to various degrees by crude root exudates of this diverse range of cereals, with the most effective being S. cereale var. Edmondo, and T. monococcum MDR037. Benzoxazinoid content of root exudates appeared to vary, with ancestral wheat lines and rye exuding fewer of these compounds than hexaploid wheat, but with greater variability between lines. Co-culture with T. aestivum var. Gravity was significantly inhibitory to early shoot growth and biomass of black-grass seedlings, but individual benzoxazinoids had no effect on black-grass in the same system. These data provide evidence that cereal-black-grass interactions are influenced by root exudates, but that their effects cannot be replicated through the direct application of individual constituent compounds

Induction of α-amylase and endosperm-imposed seed dormancy: two pioneering papers in gibberellin research

Main conclusion Two papers with quite different objectives established protocols that proved pivotal for future work on the role of gibberellins in seed germination Abstract: In their paper published in 1967, Russell Jones and Joseph Varner (Planta 72: 155-161) developed a bioassay based on induction of α-amylase activity in barley embryo-less half-seeds that was specific for bioactive gibberellins. The induction of α-amylase in the aleurone of barley and other cereals was to become the experimental system of choice to study gibberellin signalling. However, despite much progress in identifying the molecular events linking gibberellin action and α-amylase gene expression, in many cases their role in the process is still unclear. In 1987 Steven Groot and Cees Karssen (Planta 171:525-531) showed that germination of tomato seeds was limited by the ability of the radicle to penetrate the surrounding layers, with the endosperm forming the major barrier. They used a modified needle attached to a tensiometer to measure the force required to break through the endosperm. While in wild-type seeds a factor from the embryo, assumed to be gibberellin, promoted breakdown of the endosperm, gibberellin-deficient seeds required an external supply of the hormone to weaken the endosperm or for it to be mechanically disrupted for germination to occur. The paradigm of seed germination being physically restricted by surrounding layers and the role of gibberellin in weakening these tissues has been confirmed in many eudicot species. Gibberellin signalling induces the production of cell-wall loosening enzymes in the micropylar endosperm adjacent to the radicle, but it is unclear whether or not this is a direct response. In both eudicot and monocot systems, there is still much to learn about the role of gibberellin signalling in germination

Towards a sustainable phosphorus network in Africa

Global collaborative action for sustainable management of phosphorus is vital to ensure food production and the protection of water quality. This requires balancing competing phosphorus demands and a growing population through coordinated actions at local, national, regional and international scales. Phosphorus is mainly used in the agricultural sector as an essential nutrient for plant growth and animal feed. It is also used to a lesser extent in the food industry as an additive, as an additive in steel production and most recently in the production of lithium batteries for electric cars. Phosphorus is a finite resource, making its sustainable use a global priority. Yet, losses from the global phosphorus system risk pollution of aquatic ecosystems associated with biodiversity loss and human health risks associated with harmful algal blooms. While phosphorus supplies from reserves are not of immediate concern, there is nonetheless a need to ensure sustainable phosphorus use at the global level. Africa’s use of phosphorus fertilisers is sub-optimal, with a reported decline in phosphorus fertiliser use of about 233 % by the turn of the 21st century, and remains low. The Sustainable Phosphorus Summit (SPS) is the only global conference series supporting discourse on phosphorus sustainability spanning across the academic, agriculture, environmental, wastewater, policy and industry sectors. Since its inception in 2010, the SPS series has been held every 2–4 years on all continents – except Africa. The hosting of the 8th SPS (SPS8) in Accra, Ghana, will present an opportunity to set the agenda for sustainable phosphorus management in Africa, and to place African contexts into the global discussion. Being organised by different teams led by an African Local Organising Committee, SPS8 aims to pave the way towards the establishment of an African Sustainable Phosphorus Network, serving as a platform for collaboration, networking and knowledge co-creation and exchange to ensure sustainable phosphorus use in the region and beyond. Sustainable phosphorus management in Africa is feasible in the medium to long-term, with a focus on ensuring adequate phosphorus fertiliser availability, access and use, while minimising the environmental impacts from losses by matching soil-crop phosphorus needs and enhancing circular phosphorus use systems, and informing ecosystem recovery planning

Adaptations in agricultural water management in arid regions: Modelling farmer behaviour and cooperation on irrigation sustainability in Morocco

Climate change has disrupted weather patterns and heightened drought risks in arid and semi-arid regions, requiring adaptations to crop and irrigation strategies to sustain food production. This study integrates qualitative and quantitative approaches to examine the factors influencing farmers crop and irrigation management decisions, with a focus on groundwater management and drip irrigation adoption. Semi-structured interviews 70 farmers from Al Haouz Basin, Morocco provided insights into motivations for crop and irrigation choices. Inductive coding was used for qualitative responses, and data analysis examined how farm size and tenure influenced decision-making. An integrated modelling approach combining the theory of planned behaviour and structural equation modelling (SEM) was used to interpret drivers of irrigation management strategy. The interviews revealed that 83 % of farmers were concerned about groundwater decline, with 40 % identifying salinity as a major challenge. We found that falling groundwater levels and soil salinization have already impacted yields and raised concerns about further declines, prompting large-scale farmers to transition to more profitable and drought-resilient olive cultivation. Analysis of the SEM showed that attitudes toward drip irrigation efficiency, maintaining groundwater supply, and preventing increases in groundwater salinity influence farmers’ intentions regarding their water usage. Additionally, perceived behavioural control played a key role in shaping adoption behaviours, reinforcing the importance of structural and economic factors in decision-making. Land ownership conferred greater long-term perceived control over sustainable water use. However, qualitative findings revealed that cooperation on groundwater management was limited, with many farmers citing a lack of perceived benefits and logistical challenges, highlighting collective action challenges. Complexities related to subsidy applications and land tenure deter drip irrigation adoption, especially among smallholders, constraining climate change resilience. Our study contributes to understanding farmers' coping strategies and presents a foundation from which to develop evidence-based policy reforms enhancing agricultural and water sustainability across arid and semi-arid regions

Realities of using self-administered smartphone surveys to solve sustainability challenges

To fill data gaps in human-environment systems, especially in difficult to access locations, novel tools are needed to collect (near) real time data from diverse populations across the globe. Here we discuss the practicalities, constraints and lessons learnt from six field studies using high spatial and temporal smartphone surveys in six different countries. We suggest that high spatiotemporal, self-administered smartphone surveys will produce novel insights into human behaviour, attitudes and socio-economic characteristics that, when matched with high spatiotemporal resolution environmental data (e.g. from remote sensing), can be used to address sustainability challenges for global communities. Furthermore, we highlight the need for continuous refinement and improvement in future developments to enhance the efficacy of this methodology. By sharing the practical implications and constraints associated with smartphone surveys, this article contributes to the evolving landscape of data collection methods

Hyperspectral Remote Sensing for Monitoring Crop Disease: Applications, challenges, and perspectives

Crop disease presents significant threats to global food security and agricultural sustainability. Traditional monitoring methods, reliant on visual inspections and laboratory analyses, are labor intensive and unsuitable for large-scale implementation. Hyperspectral remote sensing has emerged as a promising tool for operational crop disease monitoring. Here, we provide a broad review, starting with a hyperspectral-based description of observable symptoms of common crop disease and then examining hyperspectral features, including spectral and textural features, pigment light absorption, solar induced chlorophyll fluorescence (SIF), temporal information, and auxiliary data. We also analyze the algorithms used for disease detection, including traditional statistical methods, machine learning (ML)-based methods, and physically based methods. The review highlights the effectiveness of these methods in distinguishing various stressors, detecting early disease, assessing crop resistance, and monitoring large-scale disease. Additionally, we present two case studies of uncrewed aerial vehicle (UAV)-based hyperspectral imaging for maize leaf spot monitoring. Based on a quantitative literature review, we summarize current research trends. Future research should emphasize integrating physical models with deep learning (DL), ensuring the sensitivity and robustness of spectral features and promoting international data sharing

Impact of Basalt Rock Powder on Ryegrass Growth and Nutrition on Sandy and Loamy Acid Soils

Enhanced weathering of silicate rocks in agriculture is an option for atmospheric CO2 removal and fertility improvement. The objective of our work is to characterise some of the agricultural consequences of a basaltic powder amendment on soil-crop systems. Two doses of basalt (80 and 160 t ha−1) were applied to two types of slightly acid soils (sandy or silty clayey), derived from long-term trials at Bordeaux (INRAE, France) and Rothamsted Research (England), respectively. For each soil, half of the pots were planted with ryegrass; the other half were left bare. Thus, the experiment had twelve treatments with four replications per treatment. Soil pH increased with the addition of basalt (+0.8 unit), with a 5% equivalence of that of reactive chalk. The basalt contained macro- and micronutrients. Some cations extractable in the basalt before being mixed to the soil became more extractable with increased weathering, independent of plant cover. Plant uptake generally increased for macronutrients and decreased for micronutrients, due to increased stock (macro) and reduced availability (micronutrients and P), related to pH increases. K supplied in the basalt was responsible for a significant increase in plant yield on the sandy soil, linked to an average basalt K utilisation efficiency of 33%. Our general conclusion is that rock dust applications have to be re-evaluated at each site with differing soil characteristics

Soil carbon sequestration enhanced by long-term nitrogen and phosphorus fertilization

Soil organic carbon is crucial for climate mitigation and agroecosystem sustainability, yet its depletion is concerning and its response to long-term fertilization remains unclear. Here we leverage the Broadbalk Classical Experiment at Rothamsted (UK), the world’s longest-running continuous winter wheat fertilization trial, along with 14C labelling, metagenomics and metabolomics to determine how 180 years of nitrogen (N) and phosphorus (P) fertilization impact soil organic carbon dynamics. Compared with no fertilization, long-term P, N and combined NP fertilization increased the soil organic carbon content by 10%, 22% and 28%, respectively. P application alone disproportionately increased microbial respiration (37%) and biomass (20%), limiting stable carbon formation and slightly increasing labile carbon. N application alone increased microbial carbon use and necromass accumulation efficiency, increasing mineral-associated carbon build-up. Combined NP fertilization enhanced plant-derived carbon inputs and the transformation of labile carbon into stable carbon, increasing soil organic carbon quantity and stability. A meta-analysis of the effects of fertilization duration on soil organic carbon revealed that N and P fertilization globally increased cropland soil organic carbon by 21% and 13%, and these promoting effects decreased before increasing after 16 and 34 years, respectively. Overall, long-term mineral fertilization can effectively enhance soil carbon sequestration