Agriculture, Ecosystems & Environment最新文献

{"title":"Excluding livestock from farm dams enhances native biodiversity","authors":"Kristian Bell ,&nbsp;Maldwyn J. Evans ,&nbsp;David B. Lindenmayer ,&nbsp;Ben C. Scheele ,&nbsp;David G. Smith ,&nbsp;Martino E. Malerba","doi":"10.1016/j.agee.2025.109623","DOIUrl":"10.1016/j.agee.2025.109623","url":null,"abstract":"<div><div>Amid a global biodiversity crisis and with over 50 % of the world's land dedicated to agriculture, solutions that enhance the biodiversity value of farmland are crucial. Fencing farm dams to prevent livestock access may provide numerous production and biodiversity benefits. However, we have limited information on the responses to fencing dams by various taxa, and its subsequent effect on community assemblages and ecosystem function. We investigated the impact of fencing farm dams on species richness, functional diversity, and community structure in a control-impact study in south-eastern Australia by comparing 20 fenced and 20 unfenced dams (40 dams total). We used a combination of in-person surveys, trail cameras, eDNA, and acoustic loggers to detect a wide range of fauna. We found significant differences in overall species richness, functional diversity and species composition between fenced and unfenced dams. Taxonomic groups including birds and mammals, and feeding guilds including carnivores and frugivores were more prevalent at dams that excluded livestock. Our results suggest that excluding livestock from farm dams preferentially benefits native species. At the species level, larger-bodied waterbirds such as dabbling ducks tended to prefer unfenced dams, while smaller woodland birds characteristic of nearby remnant woody native vegetation preferred fenced dams. We show that excluding livestock from farm dams has significant positive effects on biodiversity, ecosystem function and community structure.</div></div>","PeriodicalId":7512,"journal":{"name":"Agriculture, Ecosystems & Environment","volume":"386 ","pages":"Article 109623"},"PeriodicalIF":6.0,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of irrigation on vegetation, mesofauna and organic matter decomposition in Mediterranean vineyards","authors":"Emile Melloul ,&nbsp;Léo Rocher ,&nbsp;Armin Bischoff ,&nbsp;Raphaël Gros ,&nbsp;Olivier Blight","doi":"10.1016/j.agee.2025.109592","DOIUrl":"10.1016/j.agee.2025.109592","url":null,"abstract":"<div><div>Increasing temperatures and resulting stronger spring and summer drought have exponentially increased irrigation in Mediterranean vineyards. So far, little is known about the potential effects of irrigation on vineyard agroecosystems. The aim of this study is to assess the effect of vineyard irrigation on vegetation, soil mesofauna, the decomposition of organic matter, grapevine yield and berry sugar content. Five pairs of vineyards were selected in South-eastern France (Luberon), each comprising an irrigated and a non-irrigated vineyard. The irrigated vineyards received on average 60 mm of water which doubles usual summer rainfall. Under-vine vegetation and soil mesofauna were analysed during the growing season (April) and the following summer drought (August). Organic matter decomposition was tested using tea bags that were buried from January to May in the grapevine row. We found a significant difference in vegetation cover between treatments in April but not in the following August. Springtail and mite abundance were only different between treatments in August being higher in irrigated vineyards. In August, we also found significant differences between treatments in the structure of the soil mesofauna community. The effect of irrigation on the decomposition of organic matter was not significant. Grapevine yield was higher in irrigated vineyards but no effect on the chlorophyll index of grapevine leaves was found. This study highlighted the effect of irrigation showing that even moderate irrigation has significant effects on Mediterranean vineyard ecosystems. The strong increase of irrigated vineyards advocates for further research to obtain a better understanding of irrigation consequences under different pedoclimatic conditions.</div></div>","PeriodicalId":7512,"journal":{"name":"Agriculture, Ecosystems & Environment","volume":"386 ","pages":"Article 109592"},"PeriodicalIF":6.0,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Sinus management: Meandering mowing as a novel method to improve pollinator biodiversity and habitat heterogeneity in mesic grasslands” [Agric. Ecosyst. Environ. 382 (2025) 109478]","authors":"Laurian Parmentier ,&nbsp;Andy Van Kerckvoorde ,&nbsp;Jurgen Couckuyt ,&nbsp;Hans van Calster ,&nbsp;Guy Smagghe ,&nbsp;Geert Haesaert","doi":"10.1016/j.agee.2025.109588","DOIUrl":"10.1016/j.agee.2025.109588","url":null,"abstract":"","PeriodicalId":7512,"journal":{"name":"Agriculture, Ecosystems & Environment","volume":"386 ","pages":"Article 109588"},"PeriodicalIF":6.0,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143682128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Conversion of degraded forests to oil palm plantations in the Peruvian Amazonia: Shifts in soil and ecosystem-level greenhouse gas fluxes","authors":"Kristell Hergoualc’h ,&nbsp;Mariela López Gonzales ,&nbsp;Natalia Málaga ,&nbsp;Christopher Martius","doi":"10.1016/j.agee.2025.109603","DOIUrl":"10.1016/j.agee.2025.109603","url":null,"abstract":"<div><div>Oil palm (OP) expansion and associated forest clearance can significantly impact greenhouse gas (GHG) fluxes. We investigated carbon stocks and soil GHG (N₂O, CO₂, CH₄) fluxes in a degraded forest and an adjacent 17-year-old OP plantation in Peruvian Amazonia. The plantation comprised three nitrogen (N) fertilizer treatments: 0 (OPN0), 84 (OPN1), 168 (OPN2) kg N ha⁻¹ y⁻¹. Carbon stocks were inventoried across all pools. GHG and environmental parameters were monitored monthly for 11 months and (bi)daily when fertilizing the OP, with measurements taken both near and far from trees/palms. Ecosystem-scale CO₂equivalent losses from the conversion were computed by balancing carbon stock losses against N₂O emission changes. N₂O emissions (kg N ha⁻¹ y⁻¹) in the forest (6.7 ± 1.2) where litterfall N inputs were large (213 kg N ha⁻¹ y⁻¹) were 11, 5, and 3 times the emissions in OPN0 (0.6 ± 0.2), OPN1 (1.4 ± 0.2), and OPN2 (2.3 ± 0.3). In the plantation, 1 % of the N fertilizer applied was released as N₂O. Across ecosystems, N inputs primarily controlled N₂O emissions. Soil respiration (Mg C ha⁻¹ y⁻¹) was 1.4 times higher in the forest (9.1 ± 0.6) than in the plantation (7.3 ± 1, 5.5 ± 0.5, 6.5 ± 0.3 in OPN0, OPN1, OPN2). The forest was a soil CH₄ (kg C ha⁻¹ y⁻¹) sink (-1.5 ± 0.3) while all OP treatments were sources (0.2 ± 0.3, 0.7 ± 0.5, 0.2 ± 0.4 in OPN0, OPN1, OPN2). Ecosystem carbon stock losses from forest-to-OP conversion were substantial (196.8 ± 44.0 Mg CO₂ ha⁻¹ 15 y⁻¹) and partially offset (14–20 %) by decreased N₂O emissions. Complementary studies for this transition are needed to improve global GHG assessments.</div></div>","PeriodicalId":7512,"journal":{"name":"Agriculture, Ecosystems & Environment","volume":"386 ","pages":"Article 109603"},"PeriodicalIF":6.0,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contrasting grazing practices alter plant community trajectories across western Canada’s grasslands with implications for ecosystem function","authors":"Timm F. Döbert ,&nbsp;Lysandra A. Pyle ,&nbsp;Carter Case ,&nbsp;Edward W. Bork ,&nbsp;Cameron N. Carlyle ,&nbsp;Scott X. Chang ,&nbsp;Laio Silva Sobrinho ,&nbsp;Majid Iravani ,&nbsp;Mark S. Boyce","doi":"10.1016/j.agee.2025.109591","DOIUrl":"10.1016/j.agee.2025.109591","url":null,"abstract":"<div><div>Livestock grazing influences grassland biodiversity and ecosystem function. We report on the effects of adaptive multi-paddock (AMP) grazing (characterized by extended recovery periods between pulsed high animal density grazing events) on plant community composition and diversity across western Canada, compared to neighboring properties managed with conventional grazing (n-AMP). We also evaluated the influence of grazing practices, specifically stocking rate, cattle density, and variations in rest-to-grazing ratio at the start of the grazing season on plant community composition and diversity. We further explored the relationship between soil organic carbon (SOC) and plant diversity. Overall, AMP grazing, and specifically the use of high rest-to-grazing ratios early in the growing season, increased the proportion of non-native species. Native grasslands without prior cultivation had greater plant species richness, with fewer non-native species and containing phylogenetically more divergent plant communities, independent of grazing practices. The n-AMP pastures had higher functional trait dispersion, a pattern especially pronounced for tame (previously cultivated and seeded) pastures, and those with lower cattle stock densities (animals per unit area). Greater SOC was associated with communities higher in non-native plants, of lower species richness, and greater phylogenetic divergence, while no trend was identified for functional dispersion. Overall, AMP grazing did not increase plant species richness, functional diversity, or phylogenetic diversity. Instead, pulsed rotational grazing, specifically using high stock densities and extended rest periods, facilitated non-native species prevalence and reduced functional diversity. However, non-native species and lower overall species richness may benefit SOC accumulation, illustrating the challenges associated with building biodiverse plant communities with a high capacity for climate change mitigation.</div></div>","PeriodicalId":7512,"journal":{"name":"Agriculture, Ecosystems & Environment","volume":"386 ","pages":"Article 109591"},"PeriodicalIF":6.0,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of various methods of mineral fertilizer application on changes in the abundance, composition, and diversity of culturable fungi in a reduced tillage crop rotation system of winter wheat, soybean, and maize","authors":"Teresa Korniłłowicz-Kowalska ,&nbsp;Justyna Bohacz ,&nbsp;Piotr Kraska ,&nbsp;Sylwia Andruszczak ,&nbsp;Paweł Gierasimiuk ,&nbsp;Agnieszka Kubik-Komar","doi":"10.1016/j.agee.2025.109589","DOIUrl":"10.1016/j.agee.2025.109589","url":null,"abstract":"<div><div>Modifications to the tillage system and methods of fertilizer application demand investigation and assessment of their impact on microbial communities in cultivated soils. This study used cultivation-based methods to analyze the abundance, composition, similarity, and species diversity of culturable fungal communities in the rhizosphere and non-rhizosphere soil under a reduced tillage, rotational wheat-soybean-maize cultivation system. The trial involved application of subsurface mineral fertilization (NPKS), with surface fertilization serving as a reference point. Subsurface application of mineral fertilizers increases the efficiency of nutrient uptake and promotes better plant growth, and reduces fertilizer losses due to leaching and volatilization. It was demonstrated that among the 4 experimental factors tested (plant species, fertilization variant, ecological niche, and years of study), the crop had the greatest significant differential effect on the mycological indices under study. Significantly higher (α=0.05) total counts of culturable fungi in the rhizosphere and soil were recorded under cereal cultivation, i.e., maize and wheat, while the lowest counts were observed in soybean cultivation. Under maize cultivation, the composition and frequency of dominant genera of these fungi significantly differed from those under wheat cultivation, and to a lesser extent under soybean cultivation. In maize cultivation, significant differences were also observed between the rhizosphere and soil in population density distribution of certain species. The similarity in species composition decreased, while species diversity increased as a result of deep application of NPKS fertilizer in maize and soybean cultivation, as well as after surface application in wheat cultivation. Subsurface fertilization significantly increased the overall abundance of rhizospheric fungi, especially in maize. This was particularly evident in 2015 and 2016. In 2015, the abundance of rhizosphere fungi in subsurface-fertilized plots was nearly twice as high (higher NPKS dose) to 2.5 times higher (lower NPKS dose) compared to surface-fertilized treatments. The abundance of these fungi in the non-rhizosphere soil under maize cultivation was twice as high compared to subsurface fertilization. The method and dosage of fertilizer application did not cause significant differences in the population structure of dominant genera and species. Significant differences in the overall abundance of culturable fungi and the frequency of dominant genera and species populations were observed during the study years. The article discusses the reasons for differences in the overall abundance, composition, and frequency of dominant genera and species of culturable fungi, depending on the experimental factors investigated. Additionally, the taxonomic (composition) and spatial (frequency) structure of these fungi is comprehensively described.</div></div>","PeriodicalId":7512,"journal":{"name":"Agriculture, Ecosystems & Environment","volume":"386 ","pages":"Article 109589"},"PeriodicalIF":6.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143594181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of agronomic filters on arable plant communities: What weeds are we selecting for?","authors":"Darwin T. Hickman ,&nbsp;Chloe MacLaren ,&nbsp;Alexander Menegat","doi":"10.1016/j.agee.2025.109604","DOIUrl":"10.1016/j.agee.2025.109604","url":null,"abstract":"<div><div>Functional diversity in arable plant communities affects their detriment, as different arable plants occupy different niche spaces which dictate their competitiveness to the crop. This functional diversity can be examined using Grime’s CSR triangle; most common arable plants are thought to occupy a region of this triangle indicating low levels of stress tolerance, and preference for disturbance and abundant nutrition. Prior research has, however, only examined this with regard to specific management practices or cropping systems, rather than the ecological conditions they generate, the ‘agronomic filters’ applied. Using a dataset of all arable plant species in Sweden, we used multivariate statistics to determine the functional characteristics of problematic weeds, and how they differed from other plant species present in these communities. This was examined with regard to Grime’s life strategy, perceived detriment, conservation status, and preference for agronomic filters relating to nutrition, disturbance, moisture, and light. Our results show that intense agronomic management constrains the niche and limits the function of the non-crop community, with stress-tolerators (S) being absent and, as theorised, competitive and pure ruderals (CR and R respectively) overrepresented. CR strategists favoured nutrition, light and disturbance, and were often considered problematic according to agronomic experts. R strategists generally showed less preference for nutrition, and were more often considered rare and non-weedy, probably due to their lesser competitiveness. These findings can be applied by modifying the agronomic filters favoured by problematic weeds. Specifically, more effective nutrient management would break the ‘agronomic trap’ of fertilisation benefitting dominant, competitive weeds. Increased grazing or mowing is also suggested to limit plant height in favour of less competitive species, and increased cropping diversity will also alter selection for agronomic filters depending on crop niche. Using these agronomic filters, we provide a theoretical guide to achieving ecological weed management in practice.</div></div>","PeriodicalId":7512,"journal":{"name":"Agriculture, Ecosystems & Environment","volume":"386 ","pages":"Article 109604"},"PeriodicalIF":6.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biochar mitigates greenhouse gas emissions from bulk soil in wheat-corn rotation system by inhibiting biochemical decomposition","authors":"Debo He ,&nbsp;Rui Yang ,&nbsp;Yan Fu ,&nbsp;Dongni Hu ,&nbsp;Han Ma ,&nbsp;Xiaoguo Wang ,&nbsp;Zhixin Dong ,&nbsp;Bo Zhu","doi":"10.1016/j.agee.2025.109600","DOIUrl":"10.1016/j.agee.2025.109600","url":null,"abstract":"<div><div>Excessive greenhouse gas (GHG) emissions contribute to global climate deterioration and disrupt ecosystems. Although biochar and straw can enhance soil C sequestration, their effects on soil GHG emissions and the underlying mechanisms are unclear. Therefore, exploring the differences in physicochemical properties of biochar and straw and their mechanisms affecting soil GHG emissions from different perspectives is crucial for optimizing crop residue utilization strategies to balance soil C sequestration and soil GHG emissions. Herein, soil GHG emissions (CO₂, CH_4, and N₂O emissions) from bulk soils of wheat-corn rotational systems under different treatments of biochar and straw were continuously monitored for 7 years. The differences in properties between biochar and straw and their interactions with soil enzymes were analyzed via molecular simulation computational techniques to investigate the mechanisms by which biochar and straw affect soil GHG emissions. The results indicated that biochar reduced CO₂eq emission by 14028.1 kg ha⁻¹ (equivalent to 31.5 % of emissions from the control) compared to the control in a 7-year wheat-corn rotation system through the reduced interaction with soil active enzymes and the improvement of soil physicochemical properties. The active surface properties facilitated the interactions of straw with soil active enzymes and its biochemical decomposition, thus increasing CO₂eq emissions by 19242.0 kg ha⁻¹ compared the control. These findings enhance the understanding of the mechanisms by which biochar and straw affect soil GHG emissions and may improve the development of sustainable agricultural practices that balance soil C sequestration and GHG emission reductions.</div></div>","PeriodicalId":7512,"journal":{"name":"Agriculture, Ecosystems & Environment","volume":"386 ","pages":"Article 109600"},"PeriodicalIF":6.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143594180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal variation in bird species richness and abundance across contrasting farmland: The importance of heterogeneous and non-cropped habitats","authors":"Martin Šálek ,&nbsp;Lukáš Kadava ,&nbsp;Jakub Vrána ,&nbsp;Martin Mayer","doi":"10.1016/j.agee.2025.109616","DOIUrl":"10.1016/j.agee.2025.109616","url":null,"abstract":"<div><div>Knowledge concerning seasonal changes of species richness and abundance across different habitats is an important step to understand crucial landscape features for the conservation of declining species. This is especially the case in highly human-dominated agricultural landscapes, which have undergone massive changes in land use structure and intensity over the last decades. Here, we evaluated the seasonal importance of different cropped and non-cropped habitats for farmland birds, representing a rapidly declining species group, across various farmland habitat types. Using generalized linear mixed models and species-habitat networks, we studied changes in species richness, abundance, and habitat associations of farmland birds in five typical and widespread cropped or non-cropped habitat types within Central European farmland. We show that heterogeneous arable habitats had greater species richness than other habitat types, and open scrubland and heterogeneous arable habitats hosted the highest abundance of birds throughout the year. In contrast, among the studied habitat types, homogeneous arable habitat was typically associated with lower bird abundance and species richness. However, habitat associations of farmland birds changed seasonally, with heterogenous arable land being most important during the breeding season, open scrubland during post-breeding, and farmland hedges during winter. Similarly, we found clear seasonal and species-specific shifts in habitat affinity when considering species traits, such as habitat specialization, diet specialization, and nesting type. Overall, our findings provide clear evidence of the importance of heterogenous arable habitats and open scrubland in general for birds occurring in agricultural areas, and of the seasonal importance of specific habitat types for individual stages of the annual cycle, such as breeding and overwintering. This will help to identify seasonally important habitat types for the conservation of declining farmland bird species across Europe.</div></div>","PeriodicalId":7512,"journal":{"name":"Agriculture, Ecosystems & Environment","volume":"386 ","pages":"Article 109616"},"PeriodicalIF":6.0,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identifying seasonal sources and processes controlling nitrate in a typical reservoir-type headwater watershed of Eastern China using stable isotopes","authors":"Mengyao Ding ,&nbsp;Huawu Wu ,&nbsp;Haixia Zhang ,&nbsp;Qing Zhu ,&nbsp;Ruiyu Lei ,&nbsp;Kaiwen Li ,&nbsp;Hongxiang Fan ,&nbsp;Jing Li ,&nbsp;Congsheng Fu","doi":"10.1016/j.agee.2025.109615","DOIUrl":"10.1016/j.agee.2025.109615","url":null,"abstract":"<div><div>Reservoirs serves as a crucial sources of drinking water for approximately 3 billion people globally. Despite their significance, the water quality in these reservoirs faces considerable threats due to intensive anthropogenic activities within the watersheds, particularly in agricultural reservoir-type headwater watersheds. This study investigated nitrate stable isotopes (δ¹⁵N-NO₃^- and δ¹⁸O-NO₃^-), hydrochemistry, and stable water isotopes (δ²H-H₂O and δ¹⁸O-H₂O) in river water to identify nitrate sources and processes in the Tianmu Lake Basin. Results indicated a notable increase in NO₃^-N concentration during low-flow period of March, which subsequently declined during high-flow period of July. Additionally, NO₃^-N concentrations exhibited a decreasing trend from upstream to downstream. Isotopic evidence and MixSIAR model highlight the significant influence of agricultural activities on nitrate sources. The contribution of soil nitrogen (SN) remains a consistent nitrate source (29–33 %) across seasons and watersheds due to nitrogen accumulation. During low-flow period of March, intensive spring cropping operations led to an increased contribution from chemical fertilizer sources (CF; 32 %), elevating NO₃^--N concentrations. Conversely, manure and sewage (SW) emerged as the primary nitrate sources (34 %) due to reduced cropping operations and the flushing of poultry manure during high-flow period of July. Spatial variations showed that tea garden in the upstream regions contributed to a higher CF-derived NO₃^--N presence (33 %), while downstream regions, characterized by aquaculture and poultry farming, showed a significant SW contribution (38 %). Nitrogen cycling processes, influenced by high temperatures and dissolved oxygen (DO), facilitated extensive nitrification as the characteristics of increasing nitrate concentrations in the river. The correlation between NO₃^--N and δ¹⁵N-NO₃^- showed the presence of denitrification with a slower rate, resulting in a low nitrate removal efficiency. This study underscores the necessity to limit nitrogen inputs at headwaters to enhance nitrate removal efficiency throughout the watershed management cycle.</div></div>","PeriodicalId":7512,"journal":{"name":"Agriculture, Ecosystems & Environment","volume":"386 ","pages":"Article 109615"},"PeriodicalIF":6.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}