Arable Fields Research Articles

SDEWES 2023: Barriers and Possibilities for the Development of Short-Rotation Coppice as an Agroforestry System for Adaptation to Climate Change in Central European Conditions

This article compares different production, economic, and selected environmental aspects of agroforestry systems in a standard (alley cropping) and a newly proposed design with fast-growing trees grown in short-rotation coppice. Our models of agroforestry systems (AFSs) are as follows: (i) alley cropping AFS with cherry and walnut trees in single rows (tree strips) with 28 m-wide arable fields between them (crop strips), and (ii) coppiced tree belt AFS with poplars and willows and 25 m-wide arable fields between them (crop strips). To evaluate the production characteristics of trees, we used yield curves from experimental plantations in conditions of the Czech Republic from previous research projects. Cost data were collected from long-term experimental plantations and combined with current operation and energy prices. The article presents an economic methodology for assessing the competitiveness of biomass production in AFSs under the current identified market conditions. Our results show that AFSs with short-rotation coppice can have similar economic and production results as annual crops if grown on suitable sites and with appropriate quality of agronomy. In comparison, alley cropping AFSs with fruit trees would not be economically viable for farmers without a significant subsidy for establishment and maintenance in the first years after establishment. Concerning the latest economic and political developments, the product from SRC (energy woodchips) can be evaluated as strategic, increasing the producer’s independence from purchased energy fuels.

Nitrogen enrichment does not adversely affect exchangeable bases in rainfed urban arable soils of Kumasi, a tropical West African city

Urbanisation induces nitrogen (N) enrichment in tropical soils. This enhances soil acidification, leading in turn to a decrease in effective cation exchange capacity (CECe) and base saturation (BSe). Here, we investigated if and how these effects of urbanisation-induced N inputs affect the soils of tropical urban agroecosystems. Our aim was to quantify the impact of urbanisation intensity (UI) on total N (TN) contents and stocks, and to detect possible adverse N effects on soil pH, CECe, and exchangeable bases in rainfed urban arable soils of Kumasi, a tropical city in Ghana, West Africa. We analysed 618 topsoil samples (0–10 cm) from arable fields within the urban perimeter, categorised into four classes forming a gradient from low to high UI. For baseline comparison, 9 samples each from both rural arable fields and an urban forest were included. Urban arable soils generally had higher TN levels than their rural counterparts. Among the urban arable soils however, TN levels decreased with increasing UI, possibly as crop production and related N export through harvest intensified. Conversely, increasing UI correlated with increased levels of exchangeable Ca2+, K+, and Na+. No adverse N effect on soil pH, CECe, and BSe was detected. This could be explained with the strong TN-SOC relationship (R2 ≥ 0.9), and an increasingly strong relationship between exchangeable bases and TN and SOC (R2 = 0.5–0.8) with increasing UI. These relationships suggested a major common source of TN, SOC, and exchangeable bases. As the soils are neither chemically fertilised nor limed, these findings supported earlier studies that this source is provided by dumped biodegradable household waste, charred matter, ash, and construction materials. We concluded that soil N enrichment through these materials in Kumasi is accompanied by abundant bases in the same materials, which overcompensate any theoretic acidification. Our findings imply that not only can the fertility of tropical urban arable soils in cities like Kumasi be maintained, but also that the crops and ground water may not be at risk from the mobilisation of trace elements and heavy metals due to the hindered soil acidification.

Habitat use by the endangered Lesser Grey Shrike Lanius minor in Central Romania

In this paper we present data relating to nest density and habitat use by the Lesser Grey Shrike Lanius minor in the Târnava Mare Valley, Romania, using both nesting tree parameters (microhabitat), and habitat parameters measured in a 100m radius around each nest. The density of nests was 0.96 per km². Average distance between nests was 768.4m. Most of the nests (94.1%) were found in poplars, in the region of the middle third of their trunk, especially at the terminal parts of the branches. The birds preferred open habitats, with extended arable field cover. Moreover, the tree and shrub cover were small in areas used for nesting. As poplars are the preferred nesting habitats of this bird, and are scarcely represented in this area, the protection of these trees is critical for conservation of the Lesser Grey Shrike.

Synergic effects of vegetation structure and food supply underlie higher abundance of a farmland specialist bird in organic than in conventional arable fields

Organic farming is considered beneficial for farmland biodiversity. However, it is often unclear what specific factors are underlying the biodiversity benefits of this farming practice. The positive effects may be driven by factors acting at the field level represented by, for instance, the absence of pesticides, or by the factors acting at the level of entire farms represented by a higher diversity of crops and intercrops types, and higher share of semi-natural landscape elements. Distinguishing between these two groups of factors is difficult because they are confounded in heterogeneous landscapes consisting of small arable fields. However, their separation is crucial to understand the origins of organic farming effectiveness. The landscape in those Central and Eastern European countries that have undergone collectivization, such as Slovakia, Czechia or Lithuania, consists of large fields cultivated under either conventional or organic regime. These circumstances are suitable to assess the sole influence of in-field factors providing potential biodiversity benefits of organic farming. For this purpose, we selected a study area in the lowlands of the south-western Slovakia, where conventional and organic fields were situated in close proximity. Such a spatial arrangement was suitable to examine the possible influence of farming practice (i.e. organic vs. conventional) itself, minimising the influence of landscape elements. We focused on a single cereal crop, winter wheat, cultivated on both organic and conventional fields. Here, we counted the breeding abundance of the Eurasian Skylark (Alauda arvensis), a farmland specialist bird closely associated with arable fields providing both breeding and feeding habitat for this species, which may be considered as a farmland biodiversity indicator. Skylark counts were higher in organic than in conventional wheat fields throughout the season. This difference was statistically related to a higher abundance of invertebrates in samples collected in organic fields than in conventional fields. However, Skylark counts were also related to sparser crop cover in organic fields, especially at the end of the season. Sparser crop cover may improve nesting conditions and facilitate foraging. Our results indicate that organic farming may have a positive impact even at the field-level. The benefits for the Skylark, and possibly for the other farmland organisms, can be provided by the joint effects of the absence of pesticides and a suitable vegetation structure. Organic farming can thus be a suitable agri-environmental measure within the Common Agricultural Policy even in intensively used landscapes dominated by large fields.

Agriculturally Improved and Semi-Natural Permanent Grasslands Provide Complementary Ecosystem Services in Swedish Boreal Landscapes

Permanent grasslands cover more than a third of European agricultural land and are important for a number of ecosystem services. Permanent grasslands used for agriculture are broadly separated into agriculturally improved and semi-natural grasslands. High cultural and natural values linked to semi-natural grasslands are well documented. However, in boreal and hemi-boreal agricultural landscapes, less information is available about the areal coverage of improved permanent grasslands and their role for ecosystem service provision and biodiversity. In Sweden, grasslands are administratively separated into semi-natural (i.e., land that cannot be ploughed) or arable (i.e., improved temporary or permanent grassland on land that can be ploughed). We used data from a large-scale environmental monitoring program to show that improved permanent grassland (i.e., permanent grasslands on arable fields) may be a previously unrecognised large area of the agricultural land use in Sweden. We show that improved permanent grasslands together with semi-natural grasslands are both comparable but also complementary providers of a range of ecosystem services (plant species richness, plant resources for pollinators and forage amount for livestock production). However, as expected, semi-natural grasslands with the highest-level AESs (special values) show high species richness values for vascular plants, plants indicating traditional semi-natural management conditions and red-listed species. Improved permanent grasslands on arable fields are likely an underestimated but integral part of the agricultural economy and ecological function in boreal landscapes that together with high nature value semi-natural grasslands provide a broad range of ecosystem services.

Дифузни източници на замърсяване на подземните води в интензивен земеделски район в Южна България

The monitoring was conducted of groundwater and surface water in the period of 2018-2019 year, on Tsalapitsa village, near city of Plovdiv on Аlluvial-meadow soil (Fluvisol). In the scheme of study were included different land use, which reflect the great variety from loading in agroecosystems under agricultural activities - orchards, vineyards, rice fields, fields, where are grown cereals and intensive crops (diffuse or nonpoint sources). Water samples from wells in the pilot survey site were taken twice a year. It was found that the waters from wells under arable lands were characterized in most cases by alkaline reaction and content of chemical elements under or near to the maximum permissible concentration for drinking water. It was established that most of the studied elements are influenced by anthropogenic load and different land use, especially when growing vegetables. Data show that the nitrate nitrogen content in the shallow groundwater varies in a wide range, depending on the location of the studied wells. It was found that change in the nitrate concentrations depending on the land use is in the following order - vegetable crops > rice fields > arable fields > orchards etc. It‘s necessary conducting long-term monitoring to understand the dynamics and transformation of nitrogen in waters and the ongoing complex biochemical processes in the agro-ecosystem, especially in vulnerable areas with soils that are light in mechanical composition, shallow groundwater and with intensive agricultural activity.

Silaum silaus (L.) Schinz and Thell.—Habitat Conditions and Variation in Selected Characteristics of Populations at Different Densities

Grasslands are one of the most diverse and species-rich ecosystems in the agricultural landscape of Central Europe. However, they are gradually being overgrown or transformed into arable fields due to their abandonment and the intensification of economic activities. This leads to a drastic decline in biodiversity and the disappearance of many rare species, e.g., Silaum silaus. Research on Silaum silaus populations was conducted in the years 2020 and 2022. Data were obtained from two Natura 2000 sites. The Jaćmierz site is located in a dispersed range of Silaum silaus in south-eastern Poland. The site at Zagórzyce is located in a dense range of the species in the south-western part of the country. Research on the habitat conditions was conducted on two permanent study surfaces with the dimensions of 10 × 10 m. This research included a soil study and measurements of herbaceous vegetation. To determine the habitat conditions, use was also made of Ellenberg ecological indicator values. At each site, 10 phytosociological relevés were conducted with the Braun-Blanquet method. In each study year, the manner of land use was determined. For detailed population study, one permanent surface of the dimensions 10 × 10 m was marked out, on which each year the generative and vegetative specimens were counted and biometric studies were conducted on 30 randomly chosen generative specimens. The species occurred in two different meadow communities (Arrhenatheretum elatioris, Molinietum caeruleae), which were characterised by different habitat conditions, and the greatest differences were evident in the chemical properties of the soil and in the method of management. The meadows at Jaćmierz were mowed twice a year, while at Zagórzyce mowing was performed once every two years. The communities were also varied in terms of flora, characterised by a high species richness and a high Shannon–Wiener index. Silaum silaus had significantly greater numbers and an over four times higher cover coefficient at Jaćmierz. The largest differences in the analysed traits of the species occurred in the case of generative traits. It was observed that management practices at Jaćmierz had a strong influence on the condition of specimens and the population size of Silaum silaus, which was much better preserved at this site.

Population size and factors influencing the distribution of the urban pigeon Columba livia f. domestica in Pamplona

The environmental and trophic conditions of cities often give rise to very large populations of urban pigeons Columba livia f. domestica, which can cause local health and heritage problems due to accumulations of their droppings. Estimating the size of pigeon populations and defining their spatial patterns of abundance are therefore crucial for effective pigeon management in built-up areas. This article estimates the abundance of pigeons in Pamplona and the factors that explain the variability of pigeon abundance at local level. The Random Forest model of abundance at a local scale of 0.25 km2 cells had very high explanatory power, although its predictive power decreased due to this species’ gregariousness. Abundance decreased with increasing distance from the city centre, and from historic buildings and large parks, but increased as the proportion of the area covered by parks and built-up areas increased. The rock pigeon population in Pamplona was estimated at 8,030 individuals (95% CI: 6,483–9,860). The estimated density of urban pigeons for Pamplona as a whole was, on average, 218 birds/km2, although this figure varied considerably between habitats and areas: the highest values were measured in urban areas with historic buildings (exceeding 600 individuals/km2; in 35.8% of the 0.25 km2 cells, more than 200 individuals were estimated). Pigeon densities fell to ca. 250 birds/km2 in urban areas lacking large parks or green spaces whether near or far from historic buildings. In the peri-urban areas (i.e. arable fields, scrub and woodland), densities decreased to around 10–50 individuals/km2. In the city of Pamplona, although the population density of urban pigeons did not reach the numbers observed in other northern Spanish cities such as Barcelona, the habitat preference patterns in urban gradients are consistent with those documented in other European regions. We identify specific urban areas for population control and recommend measures such as feeding bans and waste and facade management to make it difficult for urban pigeons to access roosting and breeding sites in buildings.

New grasslands promote pollination but not biological pest control in nearby arable fields in the short term

Agricultural intensification is a major threat to farmland biodiversity and associated ecosystem services. Semi-natural habitats are integral to the preservation of farmland biodiversity and ecosystem services, however, the extent in which they contribute to specific services is largely unclear. We studied predation rates of ground-dwelling predatory arthropods, and pollination success within old permanent grasslands, newly established grasslands and arable fields near and far from new grasslands. We evaluated whether grassland restoration can enhance pollination and biological control in crop fields. For this purpose, we established new grassland strips within cereal fields, which directly bordered existing permanent grasslands. We evaluated if the distance to these old and new grasslands affects the delivery of the two ecosystem services within crop fields. We found significantly higher seed numbers and seed weight in sentinel plants placed in old grasslands, new grasslands and nearby arable fields compared to distant arable fields. We also found significantly decreasing seed numbers and seed weight in sentinel plants placed in distant arable fields with increasing distance from old grasslands, while pollination success was not affected by distance in nearby arable fields. Contrary, we did not find any significant effects of new grasslands on biological control. Our study showed that 3 years after establishing grasslands arable fields benefited from the proximity of flower-rich new grasslands through increased pollination success though not regarding biological control. This indicates that, on a short term, establishing new grasslands can support beneficial arthropods in providing ecosystem services such as pollination. Predators, in contrast, might take longer to establish effective populations that denote higher predation rates. Our study provides a baseline for future long-term studies to better evaluate pollination and pest control patterns within arable fields.

The Influence of Surrounding Arable Fields on the Species Diversity and Composition of Isolated Mountain Mesic Grassland Patches

This study aimed to determine the impact of arable fields on the diversity and species composition of isolated meadow patches of the order Arrhenatheretalia. The study was conducted in the Sowie Mountains and the adjacent hills (SW Poland). The species composition of the vegetation was analyzed along transects designated from the edge up to 33 m into the meadow patches. The species composition varied significantly in zones directly affected by arable fields, proving their strong negative impact on the vegetation of the mesic grasslands examined. The highest values of the diversity index were recorded 9 m away from the edge, while the lowest values were found in the direct influence zone of arable fields—2 m from the edge. In the case of apophytes, synanthropic species of local origin, the lowest values were recorded within 1 m and the highest values were recorded within 9 m. A significant change in the percentage of graminoids and dicotyledonous herbs was found between 9 m and 33 m from the edge. The study found no significant differences in habitat parameters measured with ecological indicators. Species of the Artemisietea vulgaris class effectively penetrate deep into grassland patches and can visibly degrade their vegetation.

A post-emergence herbicide program for weedy sunflower (Helianthus annuus L.) control in maize

During the last 15 years in Serbia, there has been an invasion of H. annuus across the country. Plants were initially limited to non-cultivated areas near arable fields, while in recent years the species has started to occur and establish populations in crop fields, especially into wide-row crops. We tested eight herbicides in two greenhouse experiments: 1) a dose-response study; 2) an efficacy study with reduced herbicide rates adding an adjuvant. The tested herbicides showed satisfactory weed control, where all estimated effective doses 90 (ED90) were lower than the recommended field rate for each herbicide, except for dicamba. The addition of non-ionic surfactants significantly increased the efficacy of glyphosate, mesotrione, rimsulfuron, and foramsulfuron. Whereas, there was no clear advantage to adding an adjuvant to bentazone and tembotrione, as the H. annuus population was already very sensitive (plants died in 1/8 of recommended rate in a dose-response study). All tested herbicides, except dicamba, can be used for satisfactory H. annuus control in maize, while glyphosate can be used for control of the species in non-agricultural lands.

Techno-economics and environmental sustainability of agricultural biomass-based energy potential

This paper explores the viability of utilizing agricultural biomass-based energy potential, employing mathematical, engineering, and economic modeling techniques. Moreover, the potential of a biogas-based co-digestion (CD) system, integrating its techno-economic performance and environmental sustainability in terms of electricity generation, has also been studied. In this investigation, the categorization of 25 different plant species into two groups: arable field crops (AFCs) and horticultural plants (HPs), was performed. Data was collected during the 2021‐–2022 cropping season in Bangladesh from various sources, including literature reviews, governmental, and non-governmental organizations. The findings revealed that the available agricultural biomass residues, totaling 1,02,585.75 KT, have the capacity to generate 1,33,815 million m3/year of biogas. This energy potential corresponds to 291,125.85 TJ/year or 9231.60 MW of electricity, which can fulfill 88% of the national total energy demand. In terms of levelized cost, the proposed approach is more competitive and shows a greater promise compared to other technologies. Furthermore, it demonstrates environmental friendliness by reducing CO2 emissions by 156 tons at a cost of $7/ton while earning $1092 annually from the potential carbon-credit market. This approach presents a potential solution to address Bangladesh's energy crisis. The payback period of the system ranged from 2.93 to 3.75 years, with and without the inclusion of a slurry, respectively. The recommended methods hold significant promise for meeting national energy demands. A case study was provided as a proof-of-concept (PoC) to validate the approach. This study is the first of its kind, providing valuable insights into the renewable energy potential in Bangladesh. The results will assist policymakers in formulating sustainable energy policies.

Vision based crop row navigation under varying field conditions in arable fields

Accurate crop row detection is often challenged by the varying field conditions present in real-world arable fields. Traditional colour based segmentation is unable to cater for all such variations. The lack of comprehensive datasets in agricultural environments limits the researchers from developing robust segmentation models to detect crop rows. We present a dataset for crop row detection with 11 field variations from sugar beet and maize crops. We also present a novel crop row detection algorithm for visual servoing in crop row fields. The proposed method uses deep learning based crop row skeleton segmentation method followed by a crop row scanning algorithm that identifies the central crop row which the robot then follows. The unique dataset we used with skeleton representations for crop row detection enables robust crop row detection in challenging real world field conditions. Our algorithm can detect crop rows against varying field conditions such as curved crop rows, weed presence, discontinuities, growth stages, tramlines, shadows and light levels. Dense weed presence within inter-row space and discontinuities in crop rows were the most challenging field conditions for our crop row detection algorithm. An End-of Row detector algorithm was developed to detect the end of the crop row and navigate the robot towards the headland area when it reaches the end of the crop row.

Severe decline in abundance of Cyathostoma lari, a parasite of the nasal and orbital sinuses of gulls, at their central European nesting grounds.

Cyathostoma lari is a parasite of the nasal and orbital sinuses of gulls and other hosts in Europe and Canada. Here, we provide an overview of previously published data on the prevalence and infection intensity of C. lari in gulls. Furthermore, based on our data, we analyze the spatiotemporal trends in the prevalence and intensity of infection by C. lari in Chroicocephalus ridibundus in Czechia (central Europe; data from 1964 to 2014) and compare them with those obtained from five species of gulls in Karelia (Northwest Russia; data from 2012-2020). Based on our preliminary observations, we hypothesized that C. lari is subject to a decline in certain regions, but this decline is not necessarily applicable throughout its distribution range. We found that the C. lari population crashed in specific parts of its distribution range. The reasons are unknown, but the observed population changes correspond with the diet switch of their core host in Czechia, C. ridibundus. We previously observed a diet switch in Czech C. ridibundus from earthworms (intermediate hosts of C. lari) to other types of food. This diet switch affected both young and adult birds. Nevertheless, it may not necessarily affect populations in other regions, where they depend less on earthworms collected from agrocenoses affected by agrochemicals and trampling. Correspondingly, we found that these changes were limited only to regions where the gulls feed (or fed) on arable fields. In Karelia, where arable fields are scarce, gulls likely continue to feed on earthworms and still display high infection rates by C. lari. Therefore, C. lari, a parasite of the nasal and orbital sinuses of gulls, nearly disappeared from their central European nesting grounds but is still present in better-preserved parts of its distribution range.

Application of DSS in agroecological assessment of the potential of use of chernozem soils in the conditions of the Penza region

The paper discusses the use of a decision support system (DSS) for the purpose of automated agroecological assessment of chernozem soils of the Penza region in comparison with the agroecological classification of soil cover based on standard agrochemical characteristics. The results show the rationality of using DSS, as well as the increased agroecological potential of the analyzed old arable field. Calculations made it possible to identify limiting soil-ecological parameters, such as insufficient content of mobile forms of phosphorus and the density of the arable soil horizon, as well as to calculate the soil-ecological quality rating both for the entire field and for a regular hectare grid.

Selection of a diversionary field and other habitats by large grazing birds in a landscape managed for agriculture and wetland biodiversity

Abstract Several populations of cranes, geese, and swans are thriving and increasing in modern agricultural landscapes. Abundant populations are causing conservation conflicts, as they may affect agricultural production and biodiversity negatively. Management strategies involving provisioning of attractive diversionary fields where birds are tolerated can be used to reduce negative impact to growing crops. To improve such strategies, knowledge of how the birds interact with the landscape and respond to current management interventions is key. We used GPS locations from tagged common cranes (Grus grus) and greylag geese (Anser anser) to assess how they use and select differentially managed habitats, such as diversionary fields to decrease impact on agriculture and wetlands protected for biodiversity conservation. Our findings show a high probability of presence of common cranes and greylag geese in the protected area and in the diversionary field, but also on arable fields, potentially causing negative impact on agricultural production and wetland biodiversity. We outline recommendations for how to improve the practice of diversionary fields and complementary management to reduce risk of negative impact of large grazing birds in landscapes tailored for both conservation and conventional agriculture.

Drivers of species composition in arable‐weed communities of the Austrian–Hungarian borderland region: What is the role of the country?

AbstractQuestionsDue to their high ecological and agronomical variability, borderland regions offer an excellent opportunity to study assembly patterns. In this study we compared the influence of various factors on summer annual weed communities consisting of both native and introduced species.LocationThe borderland region of Austria and Hungary.MethodsWe assessed the abundance of weed species in 300 fields of six summer annual crops, and collected information on 26 background variables for each plot. We applied redundancy analysis (RDA) to estimate multivariate species responses and variation partitioning to compare the relative importance of three groups of variables (environmental variables, management variables, and country as a singleton group), and we also checked for statistical association between country and the predictors of the other two groups.ResultsThe full RDA model explained 22.02% of the variance in weed species composition. Variation partitioning showed that environment and management had similarly high (~8%) influence on weeds, while country had a modest yet substantial (~1%) effect, and there was relatively little overlap between the variance attributable to the three groups. Comparing the individual variables, country ranked third (after preceding crop, and actual crop). The effects of 15 further variables were also significant, including seven management, and seven environmental variables, as well as the location of the sampling plots within the fields. Comparisons between the countries showed that farming type, preceding crops, tillage system, tillage depth and field size were significantly different between the countries.ConclusionsCountry exhibited a small but significant influence on weed community composition, which could not be explained with easily accessible management and environmental variables. This suggests that the distinct historical agronomical background of the two countries, possibly involving some legacies of the former Iron Curtain period, still has an impact on the weed species composition of arable fields.

The effect of herbicides on arbuscular mycorrhizal fungi associated with annual invasive Asteroideae weeds

Invasive plants Galinsoga parviflora and Erigeron canadensis are common in crops and adjacent territories. One of the factors contributing to their spread is the community of arbuscular mycorrhizal fungi associated with these species. The nature of the symbiotic relationship between the host plant and AMF is determined by their phylogenetic position and place of growth. The aim of this work was to determine the level of mycorrhizal colonization of E. canadensis и G. parviflora growing in arable fields and along them. For plants at the flowering stage, high rates of frequency and intensity of mycorrhization were revealed. It has been shown that the level of mycorrhizal colonization of E. canadensis and G. parviflora is significantly influenced by the range of herbicides applied. The application of 2.4 D slightly reduced the intensity of colonization, but significantly stimulated the formation of arbuscules in plant roots. In turn, metribuzin prevented the formation of mycorrhiza. AMF associated with these plants formed a separate clade. This group, in our opinion, is responsible for more effective symbiosis with invasive plants of the Asteroideae subfamily and requires further closer study.

Parasitological contamination of arable soil in selected regions of Poland - preliminary study.

The hygienic status of arable soils in most developed countries has been unknown. In the presented study, a preliminary investigation was undertaken to determine the contamination with eggs of parasitic nematodes in the soil of arable fields in Poland. The aim of the study was to determine whether such contamination is common enough to constitute a significant problem and what factors may influence it. The study was conducted in 5 Polish provinces from autumn 2021 to spring 2022. The provinces differed significantly in terms of the area of agricultural land, agricultural suitability, type of soil, scale of cattle and pig breeding, production of manure and slurry, and the use of manures and organic fertilizers for fertilization. A total of 133 soil samples were collected. Parasitological examination of soil samples was carried out using the PN-Z-19006 method [1], with confirmed high sensitivity. Parasite eggs were found in a total of 67 samples, of which 56 samples contained eggs of roundworms of the genus Ascaris (an average of 3.29 eggs/100g of soil), 23 contained eggs of whipworms (an average of 1.22 eggs/100g), and 3 contained eggs of Toxocara (1 egg/100g). Differences in the percentage of positive samples were found depending on the period in which the samples were taken. The percentage of positive samples collected in autumn (53.57%) was higher than the percentage of positive samples collected in spring (48.05%). Similarly, the average number of eggs of in positive samples collected in autumn (3.43 eggs/100g) was higher than the average number of eggs in samples collected in spring (2.90 eggs/100g). Differences in the percentage of positive samples were also found depending on the region of origin of the samples.

Soil erosion, sediment sources, connectivity and suspended sediment yields in UK temperate agricultural catchments: Discrepancies and reconciliation of field-based measurements

Robust understanding of the fine-grained sediment cascades of temperate agricultural catchments is essential for supporting targeted management for addressing the widely reported sediment problem. Within the UK, many independent field-based measurements of soil erosion, sediment sources and catchment suspended sediment yields have been published. However, attempts to review and assess the compatibility of these measurements are limited. The data available suggest that landscape scale net soil erosion rates (∼38 t km−2 yr−1 for arable and ∼26 t km−2 yr−1 grassland) are comparable to the typical suspended sediment yield of a UK catchment (∼44 t km2 yr−1). This finding cannot, however, be reconciled easily with current prevailing knowledge that agricultural topsoils dominate sediment contributions to watercourses, and that catchment sediment delivery ratios are typically low. Channel bank erosion rates can be high at landscape scale (27 km−2 yr−1) and account for these discrepancies but would need to be the dominant sediment source in most catchments, which does not agree with a review of sediment sources for the UK made in the recent past. A simple and robust colour-based sediment source tracing method using hydrogen peroxide sample treatment is therefore used in fifteen catchments to investigate their key sediment sources. Only in two of the catchments are eroding arable fields likely to be important sediment sources, supporting the alternative hypothesis that bank erosion is likely to be the dominant source of sediment in many UK catchments. It is concluded that the existing lines of evidence on the individual components of the fine sediment cascade in temperate agricultural catchments in the UK are difficult to reconcile and run the risk of best management interventions being targeted inappropriately. Recommendations for future research to address paucities in measured erosion rates, sediment delivery ratios and suspended sediment yields, validate sediment source fingerprinting results, consider the sources of sediment-associated organic matter, and re-visit soil erosion and sediment cascade model parameterisation are therefore made.