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Agricultural land lacks resistance to water erosion during the wettest winters of the past decade
No full textWith changing climate and increased frequency of wet weather extremes, increased attention is being directed towards understanding the resilience of agroecosystems and the goods and services they deliver. The world’s most instrumented and monitored farm (the North Wyke Fam Platform - a UK National Bioscience Research Infrastructure) has been used to explore the resilience of sediment loss regulation delivered by lowland grazing livestock and arable systems under conventional best management. The robustness of water quality regulation was explored using exceedance of modern background (i.e. pre-World War II) net soil loss rates (i.e., sediment
delivery) during both typical (2012–13, 2015–16) and the most extreme (2013–14, 2019–20, 2023–24) winters (December - February, inclusive), in terms of seasonal rainfall totals, over the past decade. Exceedances of maximum modern background sediment loss rates from pasture were as high as 2.4X when scheduled ploughing and reseeding for sward improvement occurred immediately prior to the winters in question. Exceedances of maximum modern background sediment loss rates in the arable system (winter wheat and spring oats) were as high as 21.7X. Over the five monitored winters, the environmental damage costs for cumulative sediment loss
from the permanent pasture system ranged from £ 163–203 and £197–245 ha−1 to £ 321–421 and £ 386–507 ha−1. Over the same five winters, environmental damage costs for cumulative sediment loss from catchments subjected to reseeding and, more latterly, arable conversion, ranged between £ 382–584 and£ 461–703 ha−1 to £ 1978–2334 and £ 2384–2812 ha−1. Our data provide valuable quantitative insight into the impacts of winter rainfall and land use on the resilience of sediment loss regulation
DeepCanola: Phenotyping brassica pods using semi-synthetic data and active learning
No full textPhenotyping, the measurement of attributes or traits, is crucial in selecting superior cultivars for specific environmental situations. This is a time-consuming process when applied to large populations but can be accelerated through the use of deep learning, resulting in an algorithm that can phenotype images of specimens in negligible amounts of time. The primary issue with deep learning is the large quantities of high-quality training data required to make a viable phenotyping pipeline. To address this, we present a semi-synthetic training data generation system which significantly reduces the amount of human effort spent on data collection. We use active learning alongside this system to create DeepCanola, an instance segmentation model that successfully segments and measures the valves from Brassica napus pods. We demonstrate that the model accurately estimates the effect of different winter cold treatments on a range of different cultivars and crop types as effectively as manually curated measurements. Furthermore, the resulting model is effective on data from various experimental settings and on different, but related, species such as Arabidopsis thaliana, Allaria petiolate (garlic mustard) and Raphanus raphanistrum subsp. sativus (radish). This robust tool could be easily scaled, thereby accelerating breeding or fundamental research programs. Code and model weights: https://github.com/kieranatkins/deepcanola
Concerted transport and phosphorylation of diacylglycerol at ER–PM contact sites regulate phospholipid dynamics during stress
No full textA universal response of plants to environmental stresses is the activation of plasma membrane (PM) phospholipase C, which hydrolyzes phosphoinositides to produce soluble inositol phosphate and diacylglycerol (DAG). Because of their conical shape, DAG amounts have to be tightly regulated or they can destabilize membranes. We previously showed that upon stress, Synaptotagmin1 (SYT1) transports DAG from the PM to the endoplasmic reticulum (ER) at ER–PM Contact Sites (CS). Here, we addressed the fate of the incoming DAG in the ER. We show that diacylglycerol kinases (DGKs) DGK1 and DGK2 form a module with SYT1 functionally coupling DAG transport and phosphorylation at ER–PM CS. Although SYT1 and DGK1/DGK2 do not show exclusive ER–PM CS localization, their interaction occurs specifically at ER–PM CS and the removal of ER–PM CS abolishes the interaction. Lipidomic analysis of a dgk1dgk2 double mutant supports that DGK1 and DGK2 phosphorylate DAG at the ER and transcriptomic and phenotypic analyses indicate that SYT1 and DGK1/DGK2 are functionally related. Taken together, our results highlight a mechanism at ER–PM CS that coordinates the transfer of DAG from the PM to the ER by SYT1 upon stress and the concomitant phosphorylation of DAG by DGK1 and DGK2 at the ER. These findings underscore the critical role of spatial coordination in lipid metabolism during stress-induced membrane remodeling
Multi-year assessment of seed shedding for economically important grass weed species in Italy and the UK
No full textapproaches for future Integrated Weed Management (IWM) strategies. To be effective however, HWSC requires
that target species have high seed retention at crop harvest. Here, a multi-year assessment of seed shedding was
conducted across large geographical areas in the UK and Italy, for pernicious grass weed species that infest winter
wheat and soybean crops. In the UK, an eight year assessment of Alopecurus myosuroides seed shedding was
carried out in winter wheat crops. In Italy, seed shedding studies were conducted for three years, assessing
A. myosuroides, Avena spp. and Lolium perenne ssp. multiflorum in winter wheat, and Sorghum halepense and
Echinochloa crus-galli in soybean crops. Our results demonstrate low levels of seed retention (approximately
20 %) for A. myosuroides and Avena spp. at harvest, while higher mean seed retention (49 %) was found for
L. perenne ssp. multiflorum. As such, Avena spp. and A. myosuroides are not good targets for HWSC across the
studied locations, while HWSC could significantly contribute to L. perenne ssp. multiflorum management if
combined with further control tactics. Seed retention at soybean harvest was on average 50 % for E. crus-galli, but
higher at approximately 75 % for S. halepense. HWSC could therefore have a considerable impact on S. halepense
populations in Italian soybean fields, but only an intermediate-low impact on E. crus-galli populations. Importantly
however, we also find evidence for significant spatial and temporal variability in the extent of seed
retention for all species. This study demonstrates that the potential for HWSC varies considerably between target
weed species and highlights the importance of inter-annual variation in determining its expected performance
Farmer preferences for adopting drought-tolerant maize varieties: evidence from a choice experiment in Nigeria
No full textDrought is a major challenge to maize-producing households in sub-Saharan Africa (SSA) impacting productivity, food security, and rural farm household welfare. Drought-tolerant maize varieties (DTMVs) are improved yield-enhancing technologies that can build resilience to climate change in the majority of SSA, but they are poorly adopted. This study assesses farmers' preferences for various attributes of DTMVs and the implicit value they are willing to place on them based on a discrete choice experiment using primary data consisting of 320 maize farm households in northern Nigeria. We estimate farmers' preference heterogeneity using maximum simulated likelihood of a mixed logit model in preference and price space. The results show common preferences for drought tolerance, nitrogen use efficiency, and yield attributes. It further shows strong disutility for non-resistance to Striga attribute. We also find the role of gender, institutional and social influence significant in valuing DTMVs attributes. Understanding the market-preferred attributes of DTMVs can provide guidance on policies to promote adoption of DTMVs
Variation in suppression of black-grass by modern and ancestral cereal root exudates
No full textThis 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
Pathogens spread by high-flying wind-borne mosquitoes
No full textMosquito-borne diseases such as malaria and dengue threaten billions of people and cause the death of hundreds of thousands annually. Recent studies have revealed that
many mosquito species regularly engage in high-altitude wind-borne migration, but its epidemiological significance remains unclear. The hypothesis that high-flying mosquitoes spread pathogens over long distances has not been directly tested. Here, we report that high-flying mosquitoes are commonly infected with arboviruses, protozoans, and helminths and provide a insights into this pathogen–vector aerial network. A total of 1,017 female mosquitoes intercepted on nets suspended from helium balloons at 120 to 290 m above ground over Mali and Ghana were screened for infection with arboviruses, Haemosporida, and filariae. The mosquitoes collected at altitude comprised 61 species, across 10 genera, dominated by Culex, Aedes, and Anopheles. Infection and infectiousness (capacity to transmit a pathogen to another host inferred based on disseminated infection) rates of migrant mosquitoes were 7.2% and 4.4% with Plasmodium spp., 1.6% and 0.6% with filariae, and 3.5% and 1.1% with flaviviruses, respectively. Twenty-one mosquito-borne pathogens were identified, including Dengue, West Nile, and M’Poko viruses, 15 avian Plasmodium species including Plasmodium matutinum, and three filariids, including Pelecitus sp. Confirmed head–thorax (disseminated) infections of multiple pathogens in Culex perexiguus, Mansonia uniformis, and Anopheles squamosus reveal that pathogens carried by high-altitude wind-borne mosquitoes are capable of
infecting hosts far from their departure location. This high-altitude traffic of sylvatic pathogens (circulating in wild animals) may be key to their maintenance among enzootic foci as well as initiating outbreaks at distant locations
Regional stability and pest increase in high-flying insectmigrants over nine decades
No full textReports of serious and widespread insect declines have been a source ofconcern for years, but long-term changes in migratory insect communities—which areimportant components of large-scale ecosystem functioning—are still little understood.Most migratory insects fly at high altitudes, making quantitative investigation problem-atic. Aerial trapping is the oldest sampling method, and generally still the only one thatcan provide information on species identity and adequately sample the smaller species.However, aerial sampling is laborious, and thus sampling periods are usually not continu-ous and sampling sites are sparsely scattered worldwide. To address these issues, we inte-grated existing data obtained by sampling from aerial platforms (and some high-mountainnetting in East Asia) in a comprehensive analysis. We found that, between 1926 and 2017,the aerial density of high-flying migratory insects from samples taken about 200 m aboveEurope (eastern United Kingdom), North America (southern and central United States),and Asia (east-central China, India, and the Philippines), remained relatively stable over-all. Additionally, some key migratory agricultural pests have significantly increased overthis period, indicating that the non-pest portion of the aerial migrant community may havedeclined. Changes in the community structure of high-altitude migratory insects will beclosely associated with large-scale ecosystem changes. Thus, apart from continued long-term monitoring of agricultural insect pests and the development of diversified preventionand control methods, there is a need to protect the diversity of non-pest and beneficialmigratory insects
Spatio‐Temporal Variation in Aerial Arthropod Abundance Revealed by Weather Radars
No full textArthropod declines have been reported widely; however, a lack of comprehensive data has hindered our ability to assess their large-scale generality and drivers. Here, we used a novel and freely available dataset – atmospheric scans from a network of meteorological radars – to quantify aerial abundance of both diurnal and nocturnal arthropods across the United Kingdom, spanning different geographic regions and land cover types. Based on observations between 2014 and
2021, and across more than 35,000 km², we estimate numbers of arthropods flying over the UK at heights between 500 and 700 meters above ground at 1.12 (± 0.01) x 1013 49 individuals during the diurnal (0800–1400 UTC) and 5.02 (± 0.01) x 1012 during the nocturnal (including dusk, 1800–2200 UTC) period, showing significant spatial heterogeneity. Although spatial patterns differed, both diurnal and nocturnal arthropods increased in the south and declined mainly in the far north; on average, only nocturnal arthropods showed an overall decline. Aerial abundance of both diurnal and nocturnal arthropods showed positive relationships with woodland, grassland, and urban landcover, and negative relationships with artificial light intensity and arable landcover. Our study highlights the importance of spatial variation in temporal biodiversity trends and illustrates the need for comparative studies between nocturnal and diurnal arthropods. Notably, by extracting vertical profiles of radar reflectivity and polarization signatures, we demonstrate how weather radar datasets can be used to quantify aerial arthropod abundance, detect diurnal and seasonal activity
patterns, and examine their environmental drivers across large spatial and temporal scale
Comments on 'First Signs That National Cropland Organic Carbon Loss Is Reversing in British Topsoils' by Bentley et al
No full textLetter to the editor
In an analysis of the most recent data from the UKCEH Countryside Survey, Bentley et al. (2025) find a modest increase in soil organic carbon (SOC) stocks of topsoil in croplands across Great Britain from 2007 to 2020, and they suggest this is the first evidence of a reversal of soil carbon loss at a national scale anywhere, linked to improvements in land management. This is a significant claim, and the paper is likely to be highly cited. However, some important caveats are apparent from a close reading of the paper, and the results need to be treated with caution. The authors do say this, but in drawing conclusions, they appear to overlook this caution and the necessary caveats.
Firstly, this is a relatively small dataset given the diversity of soils and management in cropland across Great Britain. The ‘stable cropland’ data analysed is for 86 of the 1 km × 1 km Countryside Survey squares with on average 2.6 plots per square and a single soil core per plot, that is, 226 samples in total. While the single core per plot may not introduce a systematic bias for a national-scale estimate, it does greatly add to the noise in the data. Hence the large error bars on the estimated changes in Figure 2 relative to the changes.
Second, the definition of cropland is broad, including both arable and horticultural crops, and there is no information on changes in crop rotations between the samplings. But differences in SOC stocks within and between traditional rotations will be significant. In the National Soil Inventory (NSI) of England and Wales, sites that were recorded as arable at both NSI samplings had mean SOC stocks 30% smaller but rates of change 50% greater than those recorded as arable at one sampling and ley grass at the other (Kirk and Bellamy 2010). While this question of definition regarding ‘cropland’ might not introduce a systematic bias between the CS samplings, it will further add to the variance, making it more difficult to reliably detect a change in SOC between the 2007 and 2020 samplings. It also increases the likelihood that the distribution of cropland managements is not representative of the national distribution.
Third, after decades of SOC depletion following past changes in land management, rates of loss will inevitably decrease over time as a new steady-state level is approached; Johnston et al. (2009) and Powlson et al. (2022) give examples from long-term experiments. Further, as minimal SOC levels determined by SOC protection processes are approached, it is statistically more likely to see an increase in SOC concentration over time than a decrease. Prout et al. (2022) analysed SOC/clay ratios in the NSI data—clay content being a major determinant of SOC protection—and found that almost half of arable soils had SOC/clay ratios indicating a ‘degraded’ state (< 1/13) and 60% of these soils showed increases in SOC concentration between the two NSI surveys. The results reported by Bentley et al. are consistent with such trends. Also, in view of the large confidence intervals shown in Figure 2 of Bentley et al., the data could equally be interpreted as showing no change in SOC between 2007 and 2020.
Fourth, in view of the last point, measured increases in SOC stocks (or a cessation of the previous decreases) can be explained without invoking the adoption of new sustainable land management practices. Bentley et al. propose that the adoption of reduced tillage practices over the survey period could account for increased SOC in the 0–15 cm soil depth they sampled. This would be equivalent to a redistribution of SOC through the soil profile, not a net removal of CO2 from the atmosphere and therefore not a contribution to Net Zero. In any case, estimates of the proportion of UK farmers regularly practising zero tillage vary from only 7% (Alskaf et al. 2020) to 25% (Jaworski et al. 2024), but minimum tillage, which is more widely practised, will only have negligible effects on SOC stocks compared with conventional tillage (Powlson et al. 2012).
The above points illustrate the challenges in carrying out reliable and fit-for-purpose soil monitoring at national scales, given that changes in SOC and other soil properties are slow and subject to spatial variability and the interplay of numerous land management factors. However, such monitoring is essential for evidence-based soil policy and innovation in land management. We applaud the UK Government for its continuing support for the Countryside Survey and other soil monitoring initiatives. We are pleased that Bentley et al. have drawn attention to the new results emerging from the Countryside Survey but call for greater caution in interpretation. Ascribing the apparent small SOC increases seen in the CS predominantly to the adoption of improved practices is, at best, optimistic and at worst misleading for policymakers