Anthropogenic impact on ecosystems has a crucial effect on soil properties, functions and ecosystem services including biodiversity and carbon sequestration. Arable soils and soils of urban, industrial, traffic, mining and military areas (SUITMAs) are exposed to anthropogenic disturbance and transformation. Biological capacity, greenhouse gases’ emission and carbon stocks of anthropogenically-transformed soils differ considerably from natural soils but so far remain overlooked. Negative anthropogenic impacts (e.g., soil sealing, construction, and contamination) can alter and deplete soil functions and ecosystem services, whereas best-management practices (e.g., no till, crop rotation, soil engineering) can enhance the value of anthropogenically-transformed soils. Further, the development of diversified cropping systems (rotations, multiple cropping and intercrops for food, feed and industrial products) under low-input practices for conventional and organic systems could increase land productivity and crops quality, and reduce machinery, fertilizers, pesticides, energy and water demands.
The session will focus on biological diversity and capacity, carbon stocks and fluxes of anthropogenically-transformed soils at the local, regional and global scales. It will promote research achievements addressing advanced and integrated methods in monitoring and assessment of plant and microbial diversity, chemical and physical properties, biological capacity and soil health to support best management practices and nature-based solutions. Indicators and parameters of soil-plant interactions, effectiveness of crops and soil management practices will also be discussed during the session. The session format will promote knowledge and information exchange about soil micro- and mesofauna, community succession, and biochemical processes following the development and evolution of SUITMAs and arable soils. A comprehensive analysis and original case studies presenting contribution of soil biota to the ecosystem services provided by agricultural lands and urban green infrastructure, would greatly contribute to this session. Spatial variability and temporal dynamics in properties, functions and ecosystem services of arable soils and SUITMAs in the context of global changes will be discussed regarding the perspectives of sustainable development of urban and rural areas.

Convener: Viacheslav VasenevECSECS | Co-conveners: Apolline AuclercECSECS, Kristina IvashchenkoECSECS, Jean Louis Morel, Luis Parras-Alcántara, Manuel González-Rosado, Beatriz Lozano-García, Manuel Seeger
| Attendance Tue, 05 May, 10:45–12:30 (CEST)

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Chat time: Tuesday, 5 May 2020, 10:45–12:30

D2195 |
Dario Liberati, Ramilla Brykova, Maria Cristina Moscatelli, Stefano Moscatello, Emanuele Pallozzi, and Olga Gavrichkova

Release of de-icing agents is the main cause of increasing soil salinization in urban and rural areas.  Grasses are the dominant vegetation in urban lawns and are exposed to different rates of soil salinization depending on the distance to the paved salt-affected surfaces. The capacity of these ecosystems to maintain C sequestration and nutrient cycling functioning depends on the sensitivity to salinization of the main players: primary producers and their interaction with microbial community.

In this mesocosm study we aimed to evaluating the impact of soil secondary salinization rates on the functioning of Lolium perenne. Salinization treatments were applied for two months in spring, irrigating the mesocosms with the commonly used de-icing agent NaCl at two concentration, 30 mM (low salinity treatment) and 90 mM (moderate salinity treatment). The leaf physiological  responses of Lolium were assessed monitoring photosynthetic rates (A), stomatal conductance (gs)  mesophyll conductance (gm), carboxylation capacity (Vcmax). Quantitative limitation analysis (QLA) was applied to calculate the relative contribution of diffusive and biochemical limitation to photosynthesis under salinization. Productivity was estimated by regular mowing of plants to 4cm height. Finally, plants were harvested and analyzed on leaf mass per area (LMA), leaf N content and 15N isotope composition. Rhizosphere soil was sampled and analyzed on the activity of enzymes involved in the cycling of C, N, S and P. 

Salinity increased LMA and leaf N, reducing  Lolium aboveground productivity. Photosynthetic rates were almost halved under both salinity treatments. QLA shows that photosynthesis was mainly limited by gm, limitation accounting for 68% and 54% of the total limitation in 30mM and 90mM, respectively. gs reduction significantly limited photosynthesis only in 90 mM (32% of total limitation), while biochemical limitations (due to a reduction in Vcmax) remained below 20% of the total limitation in both treatments.

Mesophyll conductance to CO2 depends on leaf anatomical and biochemical traits and is usually negatively related to LMA. The increased LMA observed under salinity treatments suggests that changes in the leaf structure (like increased cell wall thickness) could be responsible for most of the A (and consequently productivity) reduction.  On the other hand, the increased leaf N content is in agreement with the lack of significant reduction in Vcmax. Accumulation of N compounds in leaves in response to salinization was accompanied by a decline in soil extracellular enzymes involved in N and other cycles. Over-competing of the microbial pool in access to nutrients by vegetation could be suggested in conditions of salinization. Because the belowground biomass was not affected, decline in C losses with salinization could be hypothesize which should balance the shortage in C inputs.     

In conclusion, salinization mainly limited A through gm limitation, probably associated  to the increased LMA. At the same time, altering the capacity of the microbial pool to compete for N,  it increased leaf N, possibly reducing  the impact of biochemical limitation on A and avoiding a further A and productivity decline.

Experiment was financially supported by the Russian Science Foundation, project No.17-77-20046.

How to cite: Liberati, D., Brykova, R., Moscatelli, M. C., Moscatello, S., Pallozzi, E., and Gavrichkova, O.: Diffusive limitation to photosynthesis and plant-microbe N competition dominate the urban lawn response to secondary salinization, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11475, https://doi.org/10.5194/egusphere-egu2020-11475, 2020.

D2196 |
Jing Ma and Fu Chen

Understanding the interactions among different soil microbial species and how they responded to disturbances are essential to ecological restoration and resilience in the damaged mining areas. This information, however, remains unclear and poorly understood. In this study, we investigated the bacterial distribution in disturbed mining areas across three provinces of China, and constructed molecular ecological networks to reveal the interactions among soil bacterial communities. Furthermore, we examined the relationship between the microbial network topology and environmental factors to show if there is a correlation between the resilience of bacterial community and external pressure. Bacterial community composition differed dramatically among the different disturbed mining areas, and bacterial diversity decreased as microbial networks became more complex. Additionally, based on the network topology, we distinguished key microbial populations among the different mining areas, such as Proteobacteria, Acidobacteria, Actinobacteria, and Chloroflexi. Moreover, the network structure was significantly correlated with soil properties (e.g., pH value, electrical conductivity value, and available phosphorus value), which suggested that microbial network interactions might change the soil resilience, then affect soil ecosystem functions. Overall, our findings provided insight into the ways in which microorganisms responded to mining activities and change the resilience by regulating their interactions in different ecosystems.

How to cite: Ma, J. and Chen, F.: Molecular ecological network complexity drives stand resilience of soil bacteria to mining disturbances among typical damaged ecosystems in China, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-6286, https://doi.org/10.5194/egusphere-egu2020-6286, 2020.

D2197 |
| Highlight
Sophie Joimel, Laure Vieublé-Gonod, Baptiste Grard, and Claire Chenu

Are Collembola flying onto green roofs?  

With a worldwide urban population projected to reach 5 billion by 2030 (Véron, 2007), the roles and benefits of urban green spaces cannot be denied, like climate regulation by trees or water flow regulation (Gómez-Baggethun and Barton, 2013). If green spaces are among the new societal expectations of urban people, they also play a crucial role in preserving biodiversity in urban areas. Among them, green roofs are a great opportunity to create green space in cities as they represent 32% of cities’ horizontal surfaces (Frazer, 2005). Their installation is also perceived as a possible way to preserve biodiversity in cities. However, the effectiveness of green roofs in supporting biodiversity, especially soil biodiversity, has rarely been studied.

Thanks to different research programmes (TROL, SEMOIRS and T4P), we investigated the taxonomic and functional collembolan biodiversity in both extensive and productive green roofs as well as in ground-level urban microfarms in order to (i) evaluate the effectiveness of green roofs in supporting soil biodiversity, (ii) identify the mechanisms of colonisation by soil organisms and (iii) separate the effect of landscape and soil conditions on collembolan communities assemblages.

Surprisingly, green roofs are supporting high levels of soil biodiversity. Despite various soil characteristics (organic matter and water avaibility), no difference was found between extensive roofs and rooftop gardens concerning the taxonomical structures of collembolan communities (e.g. species richness, abundances). In contrast, there are differences concerning both taxonomic and functional compositions. Two ways of colonisation are suggested: a passive wind dispersal − the “flying” collembolans − and a settlement through compost inputs. We conclude that stakeholders should take into account the spatial connections of green roofs with other green spaces in order to support urban soil biodiversity.

How to cite: Joimel, S., Vieublé-Gonod, L., Grard, B., and Chenu, C.: Are Collembola flying onto green roofs?, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9869, https://doi.org/10.5194/egusphere-egu2020-9869, 2020.

D2198 |
Maria Korneykova, Dmitriy Nikitin, Andrey Dolgikh, and Anastasia Soshina

The soils mycobiota of Apatity was first characterized. Significant differences in quantitative and qualitative parameters of urban soils fungal complexes of the Subarctic zone in comparison with zonal soils were revealed. It was shown that the biomass of fungi in the soil of the residential area of Umbric Leptic Entic Podzol (Arenic, Neocambic) is 0.18 – 0.20 mg/g, in the background forest soil Folic Leptic Albic Podzol (Arenic) – 0.31 mg/g. The smallest values (0.04 – 0.08 mg / g) are typical for areas with no vegetation and a densely compacted surface (playground - Leptic Entic Podzol (Arenic, Neocambic, Technic), unpaved pedestrian walkway – Umbric Leptic Entic Podzol (Arenic, Neocambic).

In the soils of recreational and forest areas, fungi were mainly in the form of mycelium (66-70% of the total biomass), while in the soils of residential and agricultural areas in the form of spores. Spores are mainly represented by small forms up to 3 microns. The amount of large spores is insignificant, but they were mainly detected in the soil of the residential area.

The number of copies of ITS rRNA genes of fungi in soils of different functional zones varies from 4.0×109 to 1.14×1010 copies/g of soil, with the highest values in the natural Podzol of the forest zone and Podzol of the unpaved pedestrian walkway.

The number of micromycetes CFU in the upper soil horizon ranges from 1×103 to 9×104 CFU/g of soil, reaching maximum values in the soil of the Umbric Leptic Entic Podzol recreation zone (Arenic, Neocambic, Technic). The features of cultivated forms of micromycetes distribution on the soil profile in different functional zones were revealed: in the Podzol of the residential area, the maximum accumulation of fungi was noted in the lower horizons, while in the soil of the recreational, agricultural and forest areas, their maximum number was noted in the top horizon. However, the first two differed from the background one in the absence of a second maximum accumulation of micromycetes in the illuvial Bs horizon.

In general, urban soils were characterized by a low species diversity of micromycetes complexes and a specific structure significantly different from the background soils. The genus Penicillium is characterized by maximum species diversity. Trichocladium griseum and Penicillium dierckxii dominate in the communities of microscopic fungi in the soil of the residential zone, P. melinii in the soil of the recreational areas and in the playground, in the soil of agricultural area Plaggic Entic Podzol (Arenic) - micromycetes of the genus Fusarium, and in the background forest soil - P. decumbens.

How to cite: Korneykova, M., Nikitin, D., Dolgikh, A., and Soshina, A.: Urban Soils Mycobiota of the Subarctic (Apatity, Murmansk region, Russia), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2062, https://doi.org/10.5194/egusphere-egu2020-2062, 2020.

D2199 |
María Martínez-Mena, Elvira Díaz-Pereira, Noelia García-Franco, Carolina Boix-Fayos, and Maria Almagro

We assess the long-term environmental impacts and delivery of several ecosystem services of crop diversification (inter-crop with legumes/cereal) in two rainfed almond (Prunus dulcis Mill.) orchards under semiarid Mediterranean conditions. In addition, the effect of the intensity of tillage practices (conventional tillage vs. reduced tillage) in the almond monocultures was also tested. The study was carried out in two farms located in the province of Murcia (South East Spain) and the experimental design consisted of nine plots (49 m long and 7 m wide) in a randomized-block design, with three replicates for each treatment: inter-crop, (IRT), monoculture under conventional tillage (MCT), and monoculture under reduced tillage (MRT). Each plot comprised five almond trees: the three central trees were used for soil measurements and the other two trees constituted guard rows (a buffer zone to avoid edge effects). The conventional tillage consists in a chisel plowing to 15 cm depth using a cultivator between three and five times a year while the reduced tillage treatments (MRT and IRT) implies ploughing only twice a year (autumn and spring), to control weeds. The tillage affects the whole plot area, including the area around the trunk base. In the monoculture, weeds are the only vegetation present between the rows. The inter-crop consists of a mix (3:1) of common vetch (Vicia sativa L.) and common oat (Avena sativa L.), sown annually during early autumn at 150 kg seeds ha-1 and mowed in May. After manually mowing, it is incorporated into the soil using a cultivator.

During ten years (2009-2018) the effects of crop diversification and reduced tillage on a range of soil quality indicators (including soil physical, chemical and biological properties) were monitored allowing the evaluation of different support, regulating and provisioning ecosystem services (e.g. carbon sequestration, water availability, crop yield).

An improvement in soil quality with the inter-crop management (IRT) was detected after three years from its implementation, after which it was maintained or slightly increased for ten years. When comparing the inter-cropping system with the monoculture one, an improvement in soil quality indicators for regulating and supporting ecosystem services was observed at the plow layer (e.g., soil bulk density decrease, as well as increases in soil water retention capacity, plant water availability, infiltration capacity, fertility, microbial activity, and OC stabilized in aggregates). During the first seven years of inter-cropping implementation, an average reduction of about 30% in the crop yield (provisioning ecosystem service) in the inter-crop treatment respect to the monoculture was observed. However, those differences decreased, or even were reversed after eight years, suggesting that the observed positive effect on crop production with inter-crops does not occur at the same time than the improvement on soil quality but several years after that. All together, these results highlight the potential of inter-cropping in woody crops as a good option to be adopted by farmers and for climate change mitigation and adaptation.

How to cite: Martínez-Mena, M., Díaz-Pereira, E., García-Franco, N., Boix-Fayos, C., and Almagro, M.: Long-term impacts of inter-cropping and reduced tillage on ecosystem services in dryland agriculture, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-3333, https://doi.org/10.5194/egusphere-egu2020-3333, 2020.

D2200 |
Fabien Ferchaud, Bruno Mary, Thidarat Rupngam, and Claire Chenu

Bioenergy crops are expected to provide biomass to replace fossil resources and reduce greenhouse gas emissions. In this context, their effect on soil carbon sequestration is of primary importance. There is a wide range of candidate crops including perennial C4 crops or annual crops but their impact on soil organic carbon (SOC) stocks remain very uncertain as shown by the wild variability in published experimental results.

In this study, we measured the changes in SOC stocks under perennial (miscanthus and switchgrass), semi-perennial (fescue and alfalfa) and annual (triticale and sorghum or maize) bioenergy crops managed with two N fertilisation rates. The experiment called “Biomass & Environment” is located in northern France on a deep loamy soil (Haplic Luvisol) and was set up in 2006. The soil was sampled at the start of the experiment, in 2011-2012 and again in 2018 (0-60 cm, 5 layers). SOC stocks were calculated at equivalent soil mass and δ13C was systematically measured and used to calculate changes in new and old SOC stocks. In 2018, the SOC distribution in different soil particle-size fractions was also characterized for some treatments.

After 12 years, there was a large increase in SOC concentration (+7.6 g kg-1 on average) under perennial crops in the surface layer (≈ 0-5 cm) but a slight decrease in deeper layers. Changes in δ13C also showed that more than half of the new SOC accumulated in the surface layer. In addition, the additional SOC storage in the first layer was found in coarse organic fractions (50-200 and 200-2000 μm) but also in the more stabilised 0-50 μm fraction. SOC concentration under semi-perennial crops increased in the two first layers (≈ 0-20 cm), from 10.2 g kg-1 in 2006 to 11.6 g kg-1 in 2018 on average and slightly decreased below. Under annual crops, a decrease in SOC concentration was observed in all layers and particularly in the third layer (≈ 20-33 cm). There was no significant effect of the N fertilisation. Over the old ploughed layer (≈ 0-33 cm), SOC stocks increased between 2006 and 2018 under perennial and semi-perennial bioenergy crops (by 3 and 2 t C ha-1 on average respectively) and decreased by 7 t C ha-1 on average under annual crops.

This study show that different bioenergy crops can have contrasted impacts on SOC stocks but also on SOC distribution in the soil profile.

How to cite: Ferchaud, F., Mary, B., Rupngam, T., and Chenu, C.: Changes in soil carbon stocks and distribution under perennial and annual bioenergy crops, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-20118, https://doi.org/10.5194/egusphere-egu2020-20118, 2020.

D2201 |
Mariano Marcos-Pérez, Virginia Sánchez-Navarro, and Raúl Zornoza

Including legumes in intercropping systems may be regarded as a sustainable way to improve soil quality, fertility and land productivity, mostly due to facilitation processes and high rhizospheric activity which can mobilize soil nutrients for plants. Improvements in production and soil quality depend on inherent soil properties, climatic conditions, adopted management practices and fertilization, among others. The aim of this study was to assess the effect of the association between broccoli (Brassica oleracea var italica) and fava bean (Vicia fava) grown under different intercropping patterns on crop production, soil organic carbon (SOC), total nitrogen (Nt), soil aggregate stability (SAS) and soil fertility, compared to a broccoli monocrop. We defined a randomised block field experiment with three replications assessing the effect of monocropping, row 1:1 intercropping, row 2:1 intercropping and mix intercropping, with 30% reduction in fertilization in intercropped systems compared to monocrop. Soil sampling took place at harvest in February 2019. Results showed that the broccoli-fava bean intercropping significantly increased the general land production, with similar broccoli yield of 20000 kg ha-1 in all treatments, plus 8000 kg ha-1 coming from fava bean. Crop diversification and fava bean cultivation even in monocrop significantly increased SOC and Nt compared to broccoli monocrop. SOC and Nt were 1.06% and 0.09%, respectively, for broccoli monocrop, while they had average values of 1.29% and 0.12%, respectively for the intercropped systems. SAS was also significantly affected by crop diversification, with increases in the proportion of the macroaggregates (size >2 mm) with intercropping. Broccoli monocrop showed an average proportion of these macroaggregates of 9.19%, while they increased up to 17.51% in intercropped systems. CEC was not significantly affected by intercropping SAS showing almost same percentage of aggregates independently of the treatment. Available P significantly increased in intercropped systems, likely due to increased microbial activity with the simultaneous growth of the two crop species. However, no significant effect of intercropping was observed with any other nutrient (Ca, Mg, K, Mn, Cu, Fe, Zn and B), suggesting that microbial communities activated by the crop association are highly related to P mobilization but not so intensively involved in other nutrients. Thus, intercropping systems like broccoli-fava bean association can be regarded as a viable alternative for sustainable crop production while increasing soil fertility despite reducing the addition of external fertilization. However, more crop cycles are needed to confirm this trend.

How to cite: Marcos-Pérez, M., Sánchez-Navarro, V., and Zornoza, R.: Intercropping fava bean with broccoli can improve soil properties while maintaining crop production under Mediterranean conditions, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11058, https://doi.org/10.5194/egusphere-egu2020-11058, 2020.

D2202 |
Maysoon Mikha and Alan Schlegel

Land sustainability could be influenced by management decisions, soil nutrients content, and soil erosion potential. This study evaluates the management that consist on two sources of nitrogen (cattle beef manure, M; and synthetic fertilizer, F) and two levels of residue removal (0% and 80%) on corn yield and soil chemical properties in a no-tillage irrigated field. The study was initiated in 2011 in Tribune, Kansas where the nitrogen treatments and residue removal were organized in randomized strip design with four replications. After Seven years of annual M addition, corn yield and soil chemical properties significantly increased compared with synthetic fertilizer. Annual residue removal at 80% level greatly reduced soil chemical properties measured especially STN, SOC, and soil P availability for subsequent crops. Residue removal at 80% show a potential to decrease soil EC compared with 0% removal, but the EC reduction was not significant. The data generated from this study shows that soil nutrients content was reduced with removing the residue even in irrigated and well fertilized field unless organic amendment was accompanied the residue removal practice.

How to cite: Mikha, M. and Schlegel, A.: Management Practices Influenced Corn Grain Yield and Soil Chemical Properties, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-116, https://doi.org/10.5194/egusphere-egu2020-116, 2020.

D2203 |
Inna Brianskaia, Vyacheslav Vasenev, and Ramilla Brykova

Пожалуйста, вставьте свой абстрактный HTHigh anthropogenic impact and the rate of urbanization result in a decrease of urban soils’ capacity to perform ecosystem services. Carbon sequestration is an important soil-based ecosystem service, which can be assessed through quantity and quality soil carbon stocks. The stability of soil organic matter (SOM) is characterized by the resistance of its constituent components to biological, chemical and physical destruction. In the study, SOME stability in peat-sand mixture used for urban soils’ construction; floodplain soil was analyzed in response to temperature-moisture conditions. The decomposition rate of various soils was assessed. Decomposition was assessed through studying microbial production of CO2. In the research the CO2 emissions were studied under following temperatures and moisture conditions: temperature – 7°C, 22°C, 30°C and 40°C and moisture – 0.2 WHC, 0.4 WHC, 0.6 WHC, 0.8 WHC, 1 WHC. Moisture affects the amount and activity of microbial biomass, controls the availability of oxygen to microorganisms, causes periods of water microbial stress and also can destabilize organic matter, resulting in increased availability of carbon to soil microorganisms. Different patterns of moisture and temperature impacts on the soil organic carbon (SOC) decomposition rates were observed. It was concluded that, depending on the qualitative composition of carbon, the impact of hydrothermal conditions on the emission of carbon dioxide changed.ML здесь.

How to cite: Brianskaia, I., Vasenev, V., and Brykova, R.: Soil organic carbon stability of urban soils and of floodplain soils under different hydrothermal conditions, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-663, https://doi.org/10.5194/egusphere-egu2020-663, 2020.

D2204 |
Alexandra Seleznyova, Alexey Yaroslavtcev, Olga Gavrichkova, Alexey Ryazanov, Julia Kovaleva, Nadezhda Ananyeva, and Riccardo Valentini

Urban trees and soil microbial communities are the key ecosystem components to provide the supporting, provisioning and regulating services that define citizen’s well-being. Understanding the relationships between physiological states, age, species of trees and microbial functional properties are needed for a management of urban areas and landscapes' engineering. The research focuses on finding linkages between a wide range of trees’ properties monitored by smart TreeTalker technology and soil functional microbial indexes in Moscow megapolis.

The study was carried out on the RUDN University campus area (Moscow, Russia), where six tree species were selected (Pinus sylvestris, Populus tremula, Acer platanoides, Tilia cordata, Picea abies, Betula pendula). TreeTalker device was installed on the preselected five trees of each species for monitoring the sap flux, vertical stability (according to digital accelerometer), spectrums of canopy reflectance, trunk and canopy air temperature and humidity. Monitoring started in May 2019. The composite soil samples (0-10) were taken under each tree at the 0.5 m distance from its stand by augering in October 2019. In the samples, the microbial biomass carbon (MBC, SIR-method), basal respiration (BR), community level physiological profile (CLPP, MicroResp) and Shannon microbial diversity index (H’) based on CLPP were determined.

Soil MBC content was significantly depended on tree species, increasing from A.platanoides to T.cordata (from 538 to 1445 µg C g-1). The microbial diversity index was lowest in soil under A.platanoides (H’=2.1) and the highest for B.pendula (H’=2.4). The soil CLPP for A.platanoides was mainly shifted to microbial response on carboxylic acids with the low reaction on amino and phenolic acids compared to other trees species (e.g. B.pendula). Soil qCO2 (BR/MBC ratio) was positively related to trees’ age (r=0.8). Response to carboxylic acids (especially oxalic) had the highest correlation with physiological properties of the trees: trunk moisture, photochemical reflectance index and vertical stability (r > -0.5).

Current research was financially supported by Russian Science Foundation [No 19-77-30012].

How to cite: Seleznyova, A., Yaroslavtcev, A., Gavrichkova, O., Ryazanov, A., Kovaleva, J., Ananyeva, N., and Valentini, R.: Soil microbial biomass, community level physiological profiles relate to tree species and its state in urban environment, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1064, https://doi.org/10.5194/egusphere-egu2020-1064, 2020.

D2205 |
Xin Shu, Yiran Zou, Liz Shaw, Lindsay Todman, Mark Tibbett, and Tom Sizmur

Cover crops are a contemporary tool to sustainably manage agricultural soils by boosting fertility, suppressing weeds and disease, and benefiting cash crop yields, thus securing future food supply. Due to the different chemical composition of crop residues from different plant families, we hypothesised that a mixture of cover crop residues may have a greater potential to improve soil health than the sum of the parts. Our experiment focused on the impact of four cover crops (clover, sunflower, radish and buckwheat) and their quaternary mixture on soil respiration and the soil microbial community in an 84-day microcosm experiment. On average adding cover crop residues significantly (P < 0.001) increased soil respiration from 29 to 343 µg C g-1 h-1 and microbial biomass from 18 to 60 µg C g-1, compared to the unamended control during 84 days’ incubation. Cover crop addition resulted in a significant (P < 0.001) alteration of the soil microbial community structure compared to that of the control. The quaternary mixture of cover crop residues significantly (P = 0.011) increased soil respiration rate by 23.79 µg C g-1 h-1 during the period 30 to 84 days after residue incorporation, compared to the average of the four individual residues. However, no significant difference in the size of the microbial biomass was found between the mixture and the average of the four individuals, indicating the mixture may invest resources which transit dormant microbial species into a metabolically active state and thus boost microbial respiration. Analysis of similarity of microbial community composition (ANOSIM) demonstrated the mixture significantly (P = 0.001) shifted microbial community structure away from buckwheat (R = 0.847), clover (R = 0.688), radish (R = 0.285) and sunflower (R = 0.785), respectively. This implies cover crop residues provide a niche specialization and differentiation on a selection of microbial communities that favour certain plant compounds. While applying cover crop residues has positive impacts on soil function, we found that applying a mixture of cover crop residues may provide greater potential to select for microorganisms or activate dormant microbial species which result in higher soil function. The outcome of this study will help seed suppliers to design, and farmers to select, novel cover crop mixtures which enhance soil function synergistically, leading to a greater potential to sustainably improve soil health.

How to cite: Shu, X., Zou, Y., Shaw, L., Todman, L., Tibbett, M., and Sizmur, T.: Do diverse mixtures of cover crop residues alter the soil microbial community and increase soil function?, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1499, https://doi.org/10.5194/egusphere-egu2020-1499, 2020.

D2206 |
| Highlight
Moreen Willaredt, Susanne Ulrich, Thomas Nehls, and Loes van Scheik

Topsoil and peat are often taken from intact rural ecosystems to supply the urban demand for fertile soils and soil-like substrates. One way of reducing this exploitation is to recycle suitable urban wastes to produce Technosols and technogenic soil-like sub­strates. In this study we investigate the role earthworms can play in improving the hydraulic properties of such a soil-like substrate.

In a four-month microcosm experiment, the influence of the earthworm species D.veneta on the hy­draulic properties of brick-compost mixture was examined. Of the ten boxes filled with ca. 11 dm³ of ground bricks (0.7 cm³ cm-3) and green waste compost (0.3 cm³ cm-3), five contained earthworms (W-boxes) and the re­maining five were used as controls (C-boxes). The substrate was periodically irrigated and the weight of the boxes and of the drained water was monitored. At the same time, images were taken from the front of the boxes to quantify the activity of the earthworms by image analysis. Before and after the experiment, water retention curves were determined from disturbed samples of the substrate using the simplified evaporation method.

After six weeks, differences between the C- and the W-boxes were evident. Micrographs showed brick-compost aggregates only for the substrates processed by earthworms. The earthworm activity leads to reduced evaporation and an increased water content in the respec­tive microcosms. The effect persists even after disturbing the substrate. The propor­tion of plant-available soil water is about 0.02 cm³ cm-3 higher for the substrate processed by earthworms (0.250 ±0.009 cm³ cm-3) compared to the control (0.230 ±0.008 cm³ cm-3).

This study shows that earthworms are capable of ingesting and processing crushed bricks together with compost. The earthworms produced aggregates which persisted after disturbance and had a positive influence on the water retention capacity of such a soil-like substrate constructed from waste.

How to cite: Willaredt, M., Ulrich, S., Nehls, T., and van Scheik, L.: Development of plant-available water in soil-like substrate derived from urban wastes and processed by earthworm Dendrobaena veneta, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-3155, https://doi.org/10.5194/egusphere-egu2020-3155, 2020.

D2207 |
Viacheslav Vasenev, Andrey Dolgikh, Olga Romzaykina, Inna Brianskaia, Mikhail Varentsov, Pavel Konstantinov, and Riccardo Valentini

Urbanization is a global tendency, which social-economic and environmental role will increase coming decades. Urbanization has a multiple effect on climate, vegetation and soils and these effects are interrelated. Specific features urban meteorological regimes including but not limited to urban heat island alters biogeochemical processes in urban vegetation and soils. Natural vegetation in cities is to a large extent substituted by introduced species. Urban soils are dominated by artificial constructions, engineered from substrates rich in organic carbon. A complex effect of the mesoclimatic anomalies in cities alter biogeochemical processes in urban soil-plat-air systems with a crucial effect on carbon balance.

This study aims to study relationships between carbon stocks and greenhouse gases’ emissions from urban soils and climatic conditions in Moscow megapolis, considering its spatial heterogeneity and history. Moscow is among the largest cities in the world, Rapid urbanization of recent decades has evoked complex and ambiguous effects on soil C stocks and emissions. Soil sealing resulted from building and road construction directly reduces C stock in topsoils and indirectly effects soil respiration by salinization, pollution and over-compaction. On the other hand, establishment of new green zones brings an additional input of C through adding C-rich materials for engineering urban soils and stimulating production of root biomass by fertilization, irrigation and other practices maintaining urban green infrastructure. The research included several steps. At first, an intensive soil survey was organized in Moscow on summer 2019. Sampling scheme covered all the megapolis area and considered different functional and historical zones. Mixed topsoil (0-20 cm) samples were collected in total 240 locations. Total, organic and inorganic C was measured at the collected samples and C stocks were estimated. Second, microbial respiration in contrast soil moistures (4-5 points on water saturation curve) and temperatures (10, 20, 30 and 40ºC) were measured in standard lab conditions by gas chromatography. The multiple regression equations relating C stocks and microbial respiration to soil temperature, moisture and adjustment soil properties were developed. Finally, a regional climate model COSMO-CLM was adapted to the case of Moscow megapolis to estimate dynamics of soil temperature and moisture regimes. The investigated relationships were used to generate maps of C stocks and microbial respiration of urban soils in Moscow as affected by mesoclimatic anomalies.

Acknowledgements The experimental research was performed with the support of Russian Science Foundation project № 19-77-30012. The modelling part was carried out with the support of Russian Science Foundation project № 18-35-20052.

How to cite: Vasenev, V., Dolgikh, A., Romzaykina, O., Brianskaia, I., Varentsov, M., Konstantinov, P., and Valentini, R.: The effect of urban heat island and other mesoclimatic anomalies on soil C stocks and fluxes in Moscow megapolis, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-3832, https://doi.org/10.5194/egusphere-egu2020-3832, 2020.

D2208 |
Gorbov Sergey, Skripnikov Pavel, and Bezuglova Olga

Soil water-soluble organic matter (WSOM) is the most dynamic and least stable component of humus. It takes a direct part both in leading soil processes and in the formation of effective soil fertility. Its components are involved in the creation of a water-resistant structure, also exhibit physiological activity, and be of service as energy material by microorganisms. The total content of organic matter in the soils of the Rostov agglomeration varies widely: from 1.5 to 7.0%. Long-term studies of soils of the Rostov agglomeration forest-park zones showed that the organic carbon content in these soils increases under tree vegetation. This is due to changes in microclimate conditions and the associated longer period of vegetation of herbaceous vegetation. The WSOM content was obtained by summing the results of cold and hot extraction in natural soils. Its gradually decreases with depth repeating the profile dynamics of the organic carbon content in general. The surface horizons of native chernozems in a forest park and in a virgin land have the highest content of WSOM. It can be concluded that the WSOM pool is directly proportional to the stock of incoming plant residues. The maximum of extracellular enzymes activity was obtained in upper most biogenic soil horizons in the natural city soils. The highest activity was record for the enzyme, which is responsible for the nitrogen cycle (arginine-aminopeptidase (Agr)) and for the phosphorus cycle (acid phosphatase (Pho)). The enzymes activity decreases down the soil profile. 

For anthropogenically transformed soils, the WSOM profile distribution indicates a peculiar two-member structure of soil profile. The transformed upper urbiс horizons was demonstrate the absence of any patterns in its distribution. In the buried horizons of Technosols, were have the same profile trends and the same absolute values of the organic carbon content such us presented in native chernozems. Despite the high humus content in natural soils (5–7%), most of it is strongly associated with calcium ions. As a result, WSOM has values not exceeding 0.14% of the soil as a whole, or 4% in terms of organic carbon. For the urban horizons of anthropogenically transformed soils, WSOM values are not exceeding 0.04% of the soil, or about 2% in terms of organic carbon. The inversions of enzyme activity are often observed in anthropogenically transformed soils. The enzymatic activity is higher in buried humus-accumulative horizons of urbostratozems than in overlying horizons of the urbic. 

How to cite: Sergey, G., Pavel, S., and Olga, B.: Water-soluble organic matter and enzymatic activity of urban soils of Rostov aglomeration , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-5105, https://doi.org/10.5194/egusphere-egu2020-5105, 2020.

D2209 |
Gheorghe Stegarescu, Jordi Escuer, Karin Kauer, and Endla Reintam

The organic residues amendments have been widely studied for their essential role of enriching the soil with organic matter. Although the pathways of the fresh organic matter additions are very complex, so is the effect. Thus, the quality of the crop residues incorporated into the soil is a valuable attribute when deciding to switch to conservation agriculture. The different C/N ratio and biochemical composition of the crop residues will affect in various ways soil CO2, N2O and CH4 emissions and soil structural stability. The study explores the effect of different crop residues incorporated in the soil on greenhouse gas emissions and aggregate stability. The incubation experiment consisted of five treatments: control (just soil), sand (as reference), soil mixed with wheat straw, soil mixed with green fresh rye residues and soil mixed with green fresh oilseed rape residues. The residues were applied into the soil at a rate of 6 g C kg-1 of soil. The pots of all the treatments were placed for incubation for 105 days at approximately 23 oC and covered with dark plastic bags. The wetting procedure was done five times at 0-11-26-46-75 days to bring the soil to field capacity for water. The sampling for the gas emissions and aggregate stability was done before wetting and after wetting. The gas emissions were sampled using the chamber method and analysed in a Gas Chromatographer. The water-stable aggregates were analysed using the wet sieving method. The plant material was chemically analysed for total carbon and nitrogen and the biochemical composition on Fourier Transform Infrared Spectroscopy. The results revealed that the cumulative CO2 emissions in oilseed rape were 8% higher than in rye treatment. Also, it was 76% higher than in wheat straw treatment and 95 % higher than in control treatment. The highest cumulative N2O emissions were registered in rye treatment 18.79 (±0.48) mg m-2 h-1. Oilseed rape treatment had 19% lower cumulative emissions compared to rye and 98 % higher compared to control and wheat straw treatments. Both rye and oilseed rape had a low C/N ratio 12 and 10, respectively whereas wheat straw had 98 C/N ratio. From a biochemical point of view, the wheat straw was richer in stable compounds such as lignin, cellulose and hemicellulose followed by rye and oilseed rape which had a higher content of labile compounds such as sugars and easily decomposable proteins. In general mean aggregate stability increased significantly only in the wheat straw treatment being 34.69% ±1.35. 

In conclusion, this study showed that crop residues with low C/N ratio have a negative effect on greenhouse emissions. But do not have a long term effect on the increase of aggregate stability. On the contrary, the wheat straw has a positive impact on greenhouse gases, and it increased aggregate stability. 

How to cite: Stegarescu, G., Escuer, J., Kauer, K., and Reintam, E.: Crop residues amendments quality and effect on greenhouse gas emissions and aggregate stability, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-5973, https://doi.org/10.5194/egusphere-egu2020-5973, 2020.

D2210 |
David Richard, Laura Leimbrock, Gilles Rock, René Diederich, Guy Reiland, and Stéphanie Zimmer

With a high protein content (± 40 %) and an optimal amino acid composition, soybean (Glycine max (L.) Merr.), a member of the family Leguminosae, is one of the most important feed protein sources in animal nutrition. By signing the European Soy Declaration in 2017, Luxembourg aims to promote the regional cultivation of protein crops, e.g. soybean. Organic soybean cultivation in Luxembourg is still in its initial stage, with knowledge gaps mainly in mechanical weed control. The aim of the project “Sustainable and resource-efficient protein production using various mechanical weed control methods in grain legume cultivation, using soybean as an example” (LeguTec) is to investigate the efficiency of the selected mechanical systems under consideration of, inter alia, weed biomass.

In 2018 and 2019, field trials took place on two organic farms in Luxembourg (in Manternach and Hostert). Five mechanical methods were tested in soybean cultivation (variety Merlin), including A) harrow, B) interrow cultivator with duck-foot shares, C) interrow cultivator with duck-foot shares and finger-weeder, D) a combination of treatments A and C, and E) mixed cropping of soybean and camelina in combination with harrow. A positive control F) weeded by hand and a negative control G) not weeded are also implemented. Field trials were set as one-factorial-exact-trial with four replicates. Weeds were counted and identified and biomass cut before and after each weed control run as well as at flowering. Weed diversity was estimated by means of the Shannon index.  Data were analysed using ANOVA (p<0.05) and appropriated pairwise comparison Tuckey tests.

In 2018, significant less weed biomass is observed in Hostert for D in comparison to A and E, and for B, C and D in comparison to A and E, in 2019. Biomass in Manternach in 2019 is significantly lower in treatment D. Globally, weed biomass at flowering tends to be lower in the hoeing treatments (B, C and D) than in the harrowing treatments. High weed pressure from the beginning on in all treatments in Hostert has limited the efficiency of weeding but with a tendency in favour of the interrow cultivator.  At the Manternach site, weed pressure was low in 2018, allowing good regulation resulting in low diversity in all treatments. Values of the Shannon index tend to be negatively affected by mechanical weeding across all field trials. In 2019, significant lower Shannon index is observed in Hostert for treatments C and D, as well as for treatment C in Manternach. Hoeing generally tends to lower the most weed diversity in addition to weed biomass. Low abundant species were more likely to disappear, while 1 to 4 species became over-dominant in each treatment.

The increased interest in regional soybean cultivation in Luxembourg due to the LeguTec project shows the need of further research on soybean cultivation to reach the long-term goal of overcoming cultivation barriers and promoting a sustainable, resource-efficient protein production in Luxembourg.

How to cite: Richard, D., Leimbrock, L., Rock, G., Diederich, R., Reiland, G., and Zimmer, S.: Effects of mechanical weed control in organic soybean cultivation on weed biomass and diversity in Luxembourg, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7564, https://doi.org/10.5194/egusphere-egu2020-7564, 2020.

D2211 |
Inna Vaseneva, Elena Kuznetsova, and Fluza Khabibullina

Microbilogical properties of urban soils were studied in Syktyvkar town (Komi Republic), in the taiga zone of Russia. Within the settlement, two different types of functional zones were compared: transport (roadside areas with limited influence of traffic and highway area) and recreation areas (parks). The soils of parks are man-changed urban soils, whereas the soils of roadside areas were mainly man-made or considerably disturbed. The investigated soils were formed on the cultural layer or buried soils and sediments of various genesis. The soil profiles included a humus-accumulative horizon in the top part, followed by an anthropogenically transformed part, underlain by a slightly modified parent rock.

The highest number of species was determined in the soils of recreational areas, including 33 species of microscopic fungi. Soils of the transport area contained 22 species. The higher number of species is associated with the development of specific for urban zone fungal complex and partial preservation of natural zonal species of fungi, mainly representatives of Penicilliumgenus. Non-typical for the taiga zone species from Aspergillus and Fusariumgenera were frequently noted. Highway areas with intensive traffic were characterized by the dominance of dark-colored melanin-containing fungi, which are conditional pathogens for humans, and increasing presence of sterile mycelium – indicator of soil disturbance. Stenotopic species which are typical for undisturbed zonal conditions were rarely isolated.

Acknowledgements The experimental research was partly supported by Russian Science Foundation project № 19-77-30012.

How to cite: Vaseneva, I., Kuznetsova, E., and Khabibullina, F.: Mycobiota in urban soils of Russian North, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10594, https://doi.org/10.5194/egusphere-egu2020-10594, 2020.

D2212 |
Virginia Sánchez-Navarro, Mariano Marcos-Pérez, and Raúl Zornoza

Legume crops have been proposed as a way of reducing greenhouse gas (GHG) emissions because both, their rhizosphere behaviour and their ability to fix atmospheric N reducing the need of external N fertilizer. Moreover, the establishment of organic agriculture has been proposed as a sustainable strategy to enhance the delivery of ecosystem services, including mitigation of climate change by decreases in GHG emissions and increases in soil C sequestration. The aim of this study was to assess the effect of the association between cowpea (Vigna unguiculata L.) and melon (Cucumis melo L.) growing in different intercropping patterns on soil CO2 and N2O emissions compared to cowpea and melon monocultures under organic management as a possible strategy for climate change mitigation. Soil CO2 and N2O emissions were weekly measured in melon and cowpea rows using the dynamic chamber method during one cropping cycle in 2019. Results indicated that melon growing as monoculture was related to increases in O cumulative emissions (0.431 g m-2) compared to the average of the rest of treatments (0.036 g m-2). Cowpea growing as monoculture was related to decreases in CO2 cumulative emissions (390 g m-2) compared with the other treatments (512 g m-2 average). However, N2O and CO2 emission patterns did not directly follow soil moisture patterns in the experimental period, with no significant correlations. Finally there were no significant differences among intercropping treatments with regard to NO2 and CO2 emissions. Further measurements are needed to monitor the evolution of GHG emissions under these cropping systems and confirm the trend observed.

How to cite: Sánchez-Navarro, V., Marcos-Pérez, M., and Zornoza, R.: A comparison between vegetable intercropping systems and monocultures in greenhouse gas emissions under organic management, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13415, https://doi.org/10.5194/egusphere-egu2020-13415, 2020.

D2213 |
Andrey Dolgikh, Dmitriy Petrov, Inna Brianskaia, Soryia Demina, Ksenia Mahinya, Olga Romzaikina, and Aleksandr Dobrianskii

Moscow is the largest megapolis in Europe. The area of sealed areas in the center of Moscow is more than 50% (without hydrological objects). Anti-icing mixtures, car traffic, aerosols, dust, trampling - all this leads to the maximum stress of ecosystems in an urban environment Soil emission is the largest component of Gross Respiration in terrestrial ecosystems, including cities. Field measurements of emission allow estimating and comparing the state of both the underground tier and the entire ecosystem in different functional zones of a city with different types of vegetation. Soil emission is the easiest to measure, as compared to other fluxes of С-exchange. In 2019, field measurements of carbon dioxide emissions were carried out at 15 key sites (15 times, 1 per 2 weeks), which showed that in the historic center, not only the temperature at different depths of the soil, soil moisture, carbon content, particle size distribution, but also the diversity of factors combined into a group of "land use", namely: human tillage, irrigation, lawn mowing, garbage removal, sprinkling peat-compost mixture, trampling, bringing anti-icing reagents, etc., have a contrasting effect on carbon dioxide emissions from urban soils. In some cases, the emission is below the conditional background values (urban forest), in other cases, it is higher up to several times, which allows a new assessment of soils of unsealed (open) areas of the center of a megapolis as an important component of the (micro-) regional C-cycle. The data obtained allow comparing the current state of the upper part of the underground tier of urban ecosystems under the maximum anthropogenic load in the territory of a modern large city, where the share of open surfaces is minimal. The territories, where the ground layer is represented by cultivated lawn, are characterized by the maximum values of soil carbon dioxide emission.

The study was supported by the Russian Research Foundation #19-77-30012 (field measurements in the periphery of Moscow) and the Russian Foundation for Basic Research #18-35-20052 (field measurements in the historic center of Moscow).

How to cite: Dolgikh, A., Petrov, D., Brianskaia, I., Demina, S., Mahinya, K., Romzaikina, O., and Dobrianskii, A.: Soil Carbon Dioxide Emission in Extreme Environment of the Center of Moscow Megapolis, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13890, https://doi.org/10.5194/egusphere-egu2020-13890, 2020.

D2214 |
Efraín Carrillo López, Carolina Boix-Fayos, Niek Verschaeren, Jesús Lucas Parra, Elvira Díaz Pereira, Noelia García-Franco, María Almagro, Pedro Pérez Cutillas, and María Martínez-Mena

Soil erosion is one of the most important processes of soil degradation, especially vulnerable are many agricultural systems of SE Spain which are being transformed from a rainfed to irrigated agriculture. Crop diversification has been raised as a possible management measure with multiple benefits to combat soil degradation. Interrill soil erosion rates and processes were assessed in three land uses in SE Spain next to each other, with the same basic characteristics (climate, lithology and soils)  representing a gradient of land use change: natural shrubland, rainfed almond crop (Prunus dulcis) on terraces and levelled citrus crops (Citrus reticulata) with street-ridge morphology. The experimental design included two diversifications in the rainfed almond: intercropping Capparis spinosa and Thymus hyemalis, respectively, while in the citrus irrigated area a rotation with Hordeum vulgare and Vicia sativa (from February to July) or Vicia faba (from October to January) were intercropped in the streets.

In the rainfed and natural area interill erosion was measured using erosion pins with a 2 or 3 x 3 x 3 scheme (2 or 3 plots of 1 m2 with 9 pins at two diversifications and control, at three different agricultural terraces). In the natural area two pin plots were set up. At the irrigated area the experimental design was a 2 x 2 x 2 scheme (2 plots (ridge; street) x 2 replicates x 2 (bare, vegetated). Pins were measured after each rain event or each month during 14 months, identifying detachment (positive values) and sedimentation (negative values) within the erosion process.

The preliminary results indicate significant higher erosion rates in the irrigated areas than in the traditional rainfed terraces (83.6±147.4 t ha-1 versus 9.59±170.34 t ha-1, respectively). Shrubland natural areas show significant higher deposition rates (-74.97±43.08 t ha-1) than recent diversified plots with Capparis and Thymus (-52.56±227.06 and -28.29±85.94 t ha-1, respectively). Neither differences within diversification type (Capparis versus Thymus) nor between control and diversifications in the rainfed almond area have been yet detected. In the Citrus irrigated area erosion rates under Hordeum vulgare and Vicia sativa were significantly higher than under Vicia faba (129.58±94.43 and 25.61±87.79 t ha-1, respectively).

So far, those preliminary results indicate that natural shrubland and traditional rainfed crop systems facilitate sedimentation rates and are effective systems for soil conservation. However, the conversion from rainfed to irrigated crops mean a significant increase of erosion rates due to a system that does not facilitate retention of detached soils. Within this temporal framework, crop diversifications, both in rainfed and irrigated systems, have not yet significantly reduced erosion rates. A longer experimentation period is necessary to determine the effect of crop diversifications on soil erosion.

How to cite: Carrillo López, E., Boix-Fayos, C., Verschaeren, N., Lucas Parra, J., Díaz Pereira, E., García-Franco, N., Almagro, M., Pérez Cutillas, P., and Martínez-Mena, M.: From natural land to irrigated crops: impact of land use change and crop diversification on interrill erosion, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-17496, https://doi.org/10.5194/egusphere-egu2020-17496, 2020.

D2215 |
Thomas Iserloh, Felix Dittrich, Cord-Heinrich Treseler, Katharina Frey-Treseler, Roman Hüppi, Johann Six, Sören Thiele-Bruhn, and Manuel Seeger

The intensification of European agriculture leads to soil degradation, reduction of biodiversity and an increased economic risk for the farmers. An approach towards solving this problem is crop diversification and the optimized use of resources. Increasing agricultural efficiency/resilience through diversification and the associated falling environmental costs could contribute to the growth of the European agricultural sector by adapting the entire value chain.

The EU-funded project DIVERFARMING (Horizon 2020 no 728003) aims to develop and deploy innovative farming and agribusiness models based on crop diversification. Germany is involved with a broad-based study in organic steep slope viticulture in Wawern (Saar Valley).

A fundamental issue of steep slope viticulture is related to vegetation management below the vines. In order to overcome problems of soil erosion and soil organic matter depletion, an increasing number of winemakers is establishing cover crops such as grasses and legumes in driving lanes. On the contrary, the area underneath the vines is typically kept free of vegetation to avoid fungal diseases and competition on water. As cover crops do not benefit to the value chain and may compete with vines on water or have other adverse effects on vine performance, an alternative strategy for vegetation management underneath vines in steep slope viticulture is required.

Therefore, intercropping vines with perennial herbs like Thyme and Oregano growing underneath is a promising cropping practice to address the abovementioned issues. Both herbs are economically valuable and originate from dry and warm environments, which are typical for most viticultural areas. Furthermore, their relatively low need for water and flat-growing habitus is assumed to be suitable to cover the soil underneath the vines in order to protect against erosion and suppress weeds without having adverse effects on vine growth and -health. They can be marketed directly or indirectly as a concentrate for cosmetics, perfumes, nutritional supplements and food.

During the 5-year project, we will investigate impacts on and interactions between crops, soil ecological and physicochemical properties as well as erosion and emission of greenhouse gases to evaluate ecological benefits of crop diversification. Selected results obtained within the first two years of investigation will be presented.

How to cite: Iserloh, T., Dittrich, F., Treseler, C.-H., Frey-Treseler, K., Hüppi, R., Six, J., Thiele-Bruhn, S., and Seeger, M.: Environmental impact of crop diversification in steep vineyards, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-17745, https://doi.org/10.5194/egusphere-egu2020-17745, 2020.

D2216 |
Igor Zamotaev, Natalia Telnova, Alexander Alexandrovskiy, Raisa Gracheva, Andrey Dolgikh, Dmitry Karelin, Yulia Konoplyanikova, Pavel Mikheev, Alexander Dobrianskiy, and Eleonora Belova

Soils formed at once abandoned and recultivated industrial waste dumping sites are key research objects both as models of soil-forming processes in underdeveloped soils and indicators of persistent or potential environmental hazards of dumps themselves. Our studies of technogenic surface-like soil formations (TSF) and soils were conducted on a closed landfill and two abandoned filtration fields from sugar factories  in Kursk region, central part of European Russia.

Key properties of TSF and soils were defined with the assessments of their ecological, microbiological state and gas-geochemical condition. Set of methods (mesomorphological and micromorphological analysis, soil chemical and physico-chemical analysis, comparatively geographical method) was used for the detection of current elementary soil processes. Seasonal dynamics of carbon dioxide, methane and nitrous oxide emissions from soils to the atmosphere was also under consideration. Main used methodology is a research of sustainable properties of soil solid-phase (“soil memory”) together with soil functioning.

Long-term time series of high-detailed remote sensing data (from archive aerial photos of 1950s to actual satellite images and UAV optical photogrammetry) provided the possibility for the retrospective remote monitoring of the all abandoned dumps in study and reconstruction of their life cycles and land cover patterns.

As a result for the three industrial waste dumping sites of different types and the varying age of abandonment and recultivation history there were elaborated schemes of chrono-functional zoning. Each chrono-functional zone is characterized by the specific set of TSF and soils. Among them, it was described technogenic surface-like soil formations of closed landfill, calcareous technosols with several thick organic layers at the bottom of abandoned field filtration cells, calcic anthrosols of field filtration cells spontaneously used for agriculture after the abandonment of sugar factories.

The study is financially supported by RFBR project № 19–29–05025–mk.

How to cite: Zamotaev, I., Telnova, N., Alexandrovskiy, A., Gracheva, R., Dolgikh, A., Karelin, D., Konoplyanikova, Y., Mikheev, P., Dobrianskiy, A., and Belova, E.: Soils of abandoned industrial wastes disposal sites: properties, processes, functioning, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19676, https://doi.org/10.5194/egusphere-egu2020-19676, 2020.

D2217 |
Manuel González-Rosado, Jesús Aguilera Huertas, Beatriz Lozano-García, and Luis Parras-Alcántara

Carbon sequestration in agricultural soils has been defined as a positive strategy to mitigate the climate change effects. To implement this strategy, it is necessary to reduce the soil physical disturbances that encourage its degradation. It is therefore essential to analyze the consequences that conventional tillage practices have on agrosystems as a first step towards developing sustainable management practices that are in line with strategies to combat climate change. In order to evaluate the conventional tillage impact in olive groves, a toposequence was carried out where three profiles of 50 cm depth each were opened in three topographical positions: summit, backslope and toeslope. The physical and chemical soil properties were analyzed, including soil organic carbon (SOC) and mean weight diameter (MWD) of the aggregates, which showed a plot scale low SOC levels and low MWD being subject to erosive processes which negatively impacts on its SOC storage capacity.

How to cite: González-Rosado, M., Aguilera Huertas, J., Lozano-García, B., and Parras-Alcántara, L.: Effects of management on soil organic carbon and structural stability in olive grove toposequences in Mediterranean areas., EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-20635, https://doi.org/10.5194/egusphere-egu2020-20635, 2020.

D2218 |
Marta Tuninetti, Luca Ridolfi, and Francesco Laio

Increasing population and changing diets toward larger proportion of meat products have driven agricultural production increase over the past decades and will probably push it in the upcoming years. The analysis of the agricultural production increase is at the centre of the international debate since the 1800-century Malthusian prediction of exponentially growing population outstripping linearly increasing production.

In this study, we show how agriculture has changed over the past decades through the concept of a newly developed land productivity (LP) indicator, which measures the amount of calories, proteins, and fats produced per hectare of land and merges the variegate macronutrients spectrum of a 140-crops production basket. Land productivity indicator adds to the more widespread (crop specific) yield indicator the nutrient content of each product.

We find that the global LP has increased by 2.6-2.9% per year over 1961-2016 for calorie and protein, and 3.7% for fat. This confirms an important boost of the global productive regime whose growing rate has been able to overcome that of population. Humans can rely on larger amounts of calories (+1640 kcal/cap/day), proteins (+69 g/cap/day), and fats (+55 g/cap/day) supply. In this global picture, different macro-regions exhibit relevant heterogeneities. In particular, we found that Eastern Asian and Latin American countries could escape the Malthusian trap around the Nineties through both LP increase and ad hoc variation in the composition of their basket of products. However, this transition seems far to happen in Sub-Saharan Africa and South Asia, where the daily productive regime has remained stable since the Sixties, despite the variation of the basket composition.

How to cite: Tuninetti, M., Ridolfi, L., and Laio, F.: History and geography of land productivity to assess the challenges for food security, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-20661, https://doi.org/10.5194/egusphere-egu2020-20661, 2020.

D2219 |
Ksenia Mahinya, Sofiya Demina, Viacheslav Vasenev, and Inna Brianskaia

In conditions of on-going urbanization, urban parks play a key role in the sustainable development of urban space. New Moscow, the territory attached to Moscow in 2012, is currently the largest area in Russia experiencing rapid and intensive urban development. New Moscow is a unique area in which over the past five years, starting in 2012, rapid urbanization has been observed, including the formation of new recreational areas in the former forest, fallow and arable territories. There are currently more than 70 parks with a different land use history on this territory. Most of them have been created or reconstructed in the last 7 years. The aim of our study is to study the state of soils and green spaces of the recreational zones of New Moscow and the impact of anthropogenic factors on them, taking into account the different history of land use. For analysis, we selected 4 parks. Two parks are formed on the site of the former arable territory, and two parks in the forest zone. At the same time, one park from a couple was closer to the old borders of Moscow, and the second at a distance of more than 15 km. In the selected territories, we conduct physical, chemical and microbiological analysis of soils, as well as assess the state of green spaces. In each of the parks, 9 or 10 points were selected in various functional areas (territories near sports and playgrounds, in the walking area, barbecue area, etc.). The selection was carried out to a depth of 50-100 cm. The top layer (0-10 cm) was selected for analysis of the carbon content in the microbial biomass (Cmic), basal respiration (BR) and CO2 production. To carry out the pH, C / N analysis, as well as the content of heavy metals in the soil, the samples were taken horizontally to a depth of 100 cm. The second stage of the study was to assess the state of woody vegetation within a radius of 20 meters from each point selected for soil analysis. Thus, we plan to obtain a comprehensive analysis of the physical, chemical and microbiological condition of the soils of the recreational zones and green spaces with a different land use history and to identify the influence of the anthropogenic factor on them.

How to cite: Mahinya, K., Demina, S., Vasenev, V., and Brianskaia, I.: Analysis of the impact of urbanization on the microbiological, chemical and morphological properties of the soil in the recreational areas of the New Moscow with a different land-use history, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21658, https://doi.org/10.5194/egusphere-egu2020-21658, 2020.

D2220 |
| solicited
José María Esbrí, Sara Gallego, JuanAntonio Campos, Fabrice Martin-Laurent, Jesus Peco, and Pablo Higueras

Mining has an adverse effect on soil quality as it is a source of heavy metal environmental pollution with direct consequences on its ecosystem services, especially those related to microbial activity. The magnitude and diversity of the impact produced by pollution is linked to the complexity and diversity of mining processes that share the same mining area. The soil will be modified, not only in the physicochemical characteristics but also physical alterations of varied typology will occur. All these changes and alterations related to mining activity are accompanied by changes in the composition, diversity and activity of soil microorganisms..
A study was carried out on a mine site showing variable degrees of contaminations with metals, to estimate the impact of mining works on the geochemistry of soils, and the activity and diversity of soil microorganisms.  The aim is to characterize the level of disturbance on the “soil health” due to the presence of different metals, related physicochemical factors, and typology of the wastes affecting the soil. Besides, the process of bacterial colonization of the wastes has been also subject of interest to our work.
The selected study area was originally a lead-silver mine. Later, a mineral treatment plant was established in the area in order to recover Zn from the primary gangue dumps. In addition spills of olive mill residues were later deposited in the area. Four composite samples from the five distinct sites differing in their characteristics were selected: tailings, dumps, olive mill residues, contaminated soil and reference soil. A range of various analyses was done on these samples including pH, electrical conductivity, organic matter, multi-elemental contents, enzymatic activity and bacterial biodiversity (16S rRNA amplicon sequencing).
Selected sampling sites have contrasted physicochemical characteristics: acidic pH was observed in dumps (3.8 in average) and neutral in tailings and soils (~6); highest conductivity was recorded in dumps (2282 microS cm-1 in average) and lowest in soils (62 microS cm-1 in average); the highest organic matter value was measured in soils amended with olive mill residues (60% in average). Heavy metals were detected in higher concentrations in dumps and olive mill residues than in tailings or soils. It is noteworthy in dump samples the maximum concentrations of metals reach 6.8% with significant amounts of Zn, Cu, Sb, Hg, Ni, Co and Mn. Highest enzymatic activities were measured in contaminated and non-contaminated soils, while lowest values were obtained in dumps and tailings soils, in accordance with the concentration of metal measured in the matrix. Next generation sequencing analysis of 16S rRNA amplicon lead to the discrimination on the different sites sampled according to bacterial composition and diversity. Most abundant bacterial phyla were Proteobacteria, Actinobacteria, Chloroflexi, Acidobacteria, Gemmatimonadetes, Bacteriodetes, TM7, Firmicutes, Cyanobacteria and Verrucomicrobia.
As a conclusion, we have found evidences of the intense affection of the metal pollution to the microbiological biodiversity, particularly that related with the presence of high Pb concentrations.

How to cite: Esbrí, J. M., Gallego, S., Campos, J., Martin-Laurent, F., Peco, J., and Higueras, P.: Biogeochemical characterization of soils affected by more than 100 years of lead mining activity., EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21474, https://doi.org/10.5194/egusphere-egu2020-21474, 2020.