Advancing towards climate-smart agriculture: the role of soil organic carbon in soil functions, ecosystem services, and agroecosystem sustainability

Development and testing of a process-based model (MOSES) for simulating soil processes, functions and ecosystem services

The unsustainable use of soil natural capital and ecosystem services is of global concern due to damage and losses on a worldwide scale. This situation is further compounded in small island developing states (SIDS), such as the Caribbean, where rapid population growth coupled with limited land space accelerates the rate of degradation of soil natural capital. The Aripo savanna is the largest surviving natural savanna in Trinidad with economic and scientific importance. Presently, there are many different land uses and land covers competing for space to the detriment of soil ecosystem services in this savanna. An ecosystem framework approach is needed to guide the development of adaptation strategies to improve the resilience of soil ecosystem for the provisioning of services, especially in the face of climate change. We reviewed the existing literature on soil ecosystem management in SIDS with particular emphasis on Aripo savanna and attempted to provide a better understanding of soil processes by developing frameworks for assessing tropical small island soil ecosystem services and soil health. In tropical island states, poor soil quality has been associated with indiscriminant land use, creating short-term economic viability. Short-term economic viability is characterized by poor practices, negatively impacting on soil and thus limiting its ability to perform ecosystem services. To improve the resilience of a society, an ecosystem-framework approach becomes necessary. Soil ecosystem health, however, cannot be represented solely by specific land use(s)/land cover(s) (LULC) but by critical descriptors that influence soil quality. This review highlights the importance of an ecosystem framework approach for the sustainable management and optimization of soil natural capital and ecosystem services in the Caribbean SIDS.

Soil biodiversity, biological indicators and soil ecosystem services—an overview of European approaches

Over half of the world’s population live currently in urban areas with future projections estimating an increase to 68% by 2050, with a projected additional 1.2 million km2 of land to be converted to urban areas by 20301. Poor practice in the construction industry, lack of established processes and lack of practitioners to undertake surveys assessing soils health prior to a development, as well as loopholes in laws and policies are key factors affecting soil health during construction. Millions of tonnes of soils coming from construction sites are being disposed of in the landfill2 but 90% is inert. Although there are policies in place advising multiple recovery pathways for construction soil (e.g. agricultural and ecological improvement schemes)3 that should take precedence, the most widely used recovery pathway is for civil engineering purposes.     Urban soils are often overlooked but they play a major role in humans’ lives as the loss of soils functions can have not only disastrous consequences (e.g. loss of soil’s water infiltration function can cause increase flooding risk) but also huge financial repercussions. Construction inadvertently impacts soil health and functionality, due to soil loss, compaction, sealing, contamination, soil carbon loss, and soil biodiversity loss. In England and Wales the current approach for assessing the effects of a development on land and soil is restricted to the protection of biomass soil function for food, fibre and timber production,4 while other soil functions that are important in local, national and context of maintaining healthy ecosystems and mitigating climate change, are ignored.        To better understand whether construction waste contamination has a serious impact on soil functioning, we carried out a study which aimed to assess the impact of three major mineral-based construction materials (concrete, brick and plasterboard) on soil multifunctionality and ecosystem services under future climates. The materials were mixed with soil in 6 different addition treatments (5, 10, 20, 30, 40, and 50% material addition) and were maintained for 5 months at three different moisture contents (10, 25 and 50%). Soil moisture, total carbon and nitrogen, microbial biomass carbon and nitrogen, ammonium and nitrate, nitrogen mineralisation rate and microorganism community structure and abundance were measured the first and the last day of the experiment. Immediate responses were observed in all variables and were sustained throughout the duration of the experiment. Preliminary results show statistically significant stepwise reductions of plant available ammonium and nitrate as the materials’ additions were increased. pH increased immediately (Day 1) following the material additions, and although the stepwise pattern was lost, the values remained significantly higher than the controls (Day 150). Our results suggest that mineral-based construction materials have a significant impact on soil functioning which warrants further investigation if these soils are to be reused under circular economy principles.      

Agriculture intensification is increasing due to food demand and consumption patterns. Intensive agriculture is based on management that promotes the maximum profit per unit of area and involves agrochemicals, irrigation and heavy machinery. The purpose is to have high crop yields and livestock productivity. This practice's implications are increasing soil degradation and the loss of ecological functions and consequently to the detriment of ecosystem condition and services. Intensive agriculture practices are related to high erosion rates, soil compaction, pollution (e.g., pesticides, herbicides, heavy metals, pharmaceuticals), nitrification and acidification, loss of fertility and productivity, desertification, diffuse pollution, ground and surface water contamination, land fragmentation, loss of biodiversity, greenhouse gases emission, air pollution and ultimately human impact. All these effects contribute dramatically to global environmental change. Soils are the base of life. Therefore, such intensive use will induce rapid degradation. This is a global reality. Shreds of evidence from the world are plentiful: Tropical rainforests destruction in Amazonia, Congo Basin and southeast Asia due to the establishment of agriculture plantations or livestock farms, irrigation in semi-arid or arid areas of central Asia and Saudi Arabia and acidification in Northeast Europe. All these forms of soil degradation have negative implications on soil ecosystem services. For instance, agriculture intensification affects multiple regulating ecosystem services. The soil loses the capacity to regulate erosion, floods, water purification, and carbon storage, contribute to microclimate regulation, and combat pests and diseases. It also hampers the soil's capacity to supply fodder, water, wild food and medicinal plants. Although crop yields may increase, intensive agriculture practices are not sustainable since they contribute to soil degradation. Without any intervention (e.g., fertilization), there will be a loss of fertility, and yields may be reduced. Also, diffuse pollution from agriculture contributes to surface water bodies' loss of biodiversity and ecosystem services. These areas are also key for food provisioning. Intensive agriculture also dramatically impacts cultural ecosystem services such as landscape aesthetics, recreation and heritage. We have many challenges ahead regarding the impacts of agriculture intensification, and it is key to halt and reduce their impacts on ecosystem services. We live in challenging times when food security needs to be ensured for a growing global population. How we can balance between food production and soil degradation? What practices are more adjusted in each context to ensure the sustainability of agroecosystems? These are key questions that need to be answered. Bottom line is that we need to develop practices to follow a sustainable path, instead of exhausting the ecosystems and their services at a dramatic pace.         AcknowledgementsWe would like to acknowledge the support of the project Enhancing ecoSysteM sERvices mApping for poLicy and Decision mAking (SELINA), financed by the European Union’s Horizon Europe research and innovation programme under grant agreement No 101060415.

<p>Fire is an essential element of the environment and a vital force for shaping landscapes all around the world. It has a critical role as driver of natural ecosystem processes and many plant communities are fire dependent aros the globe. However, although fire is a natural and regular component of some biomes in the Earth’s systems, it can become a destructive force when natural ecosystems are disturbed, fire is introduced at a rate not previously experienced, and recovery to a pre-fire state is not possible. Thus, assesing the potentially harmful environmental impacts of fire and building the underlying knowledge required to successfully manage fire makes are crucial in order to understand the role of fire in all its different dimensions. Over the past year, fires in California in the United States and in the Amazon rainforest in Brazil have grabbed the world’s attention. The increased rates of fire events in some of these areas, mostly attributed to land degradation processes, have led to international concern. More recently, several bushfires all around Australia have had dramatic impacts in the environment with 10 million hectares burned so far, including large portions of the natural environment. These unprecedented fires are predicted to affect to a large extent the soil characteristics, processes and function in several ecosystems. In this presentation, we highlight some of the most recent research published during the last year on the effects of fire on soil functions and the provision of soil ecosystem services. We also showcase some of the possible approaches to protect and conserve soil ecosystems affected by extreme fires and propose available strategies for post-fire management.</p>

Soil tillage, crop residue management, nutrient management, and pest management are among the core farming practices. Each of these practices impacts a range of soil functions and ecosystem services, including water availability for crops, weed control, insect and pathogen control, soil quality and functioning, soil erosion control, soil organic carbon pool, environmental pollution control, greenhouse gas refuse, and crop yield productivity. In this study, we reviewed relevant bibliography and then developed a simple conceptual model, in which these soil functions and ecosystem services were scored and compared between conventional, conservation, and integrated agricultural systems. Using this conceptual model revealed that the overall agro-environmental score, excluding crop yield productivity, is largest for conservation systems (71.9 %), intermediate for integrated systems (68.8 %), and the smallest for conventional systems (52.1 %). At the same time, the crop yield productivity score is largest for integrated systems (83.3 %), intermediate for conventional systems (66.7 %), and the smallest for conservation systems (58.3 %). This study shows the potential of moderate-intensity and integrated farming systems in carrying on global food security while adequately sustaining environmental quality and ecosystem services.

Soil structural vulnerability: Critical review and conceptual development

The assessment of soil functions and ecosystem services requires reliable eco-physiological indicators that capture the complexity of soil processes across scales. Long-term field experiment provides unique insights into soil carbon dynamic and functions under varying agricultural management practices and environmental conditions. In this study, we plan to conduct a meta-analysis of self-obtained field data from several long-term field experiments in Bad Lauchstädt, central Germany, to evaluate the applicability of both basic and novel eco-indicators in assessing soil health and carbon sequestration.Our analysis includes traditional indicators such as metabolic quintet (qCO2) and microbial biomass carbon to soil organic carbon ratio (MBC:SOC), alongside some potential novel indicators like active microbial fractions, particulate organic matter to soil organic matter ratio (POM/SOM), soil pore characteristics, and soil fauna. These long-term field experiments represent varying land use practices, climatic conditions, and management strategies, offering a robust dataset for testing indicator sensitivity and effectiveness.The primary objective of this research is to identify which indicators are most responsive to land use, climate variability, and seasonality at the field scale, and to explore their potential for evaluating soil functions and ecosystem services. While our data analysis is ongoing, we hypothesize that integrating basic and novel indicators will provide a comprehensive framework for soil assessment, enabling better predictions of ecosystem resilience and carbon storage potential. We look forward to presenting our findings and discussing the implications of eco-indicator-based assessments for sustainable soil management and climate change mitigation at the conference.

Urban soils exhibit a wide diversity of properties that have no equivalent in other environments but are overwhelmingly perceived as degraded by decision makers. As a result, their potential is not considered in urban planning even though they can deliver a range of ecosystem services. This paper describes a decision support tool for assessing soil ecosystem services to support urban land use planning. An overview of existing methods for assessing ecosystem services provided by urban soils has been detailed. Destisol, a model developed specifically for the urban context, is presented in detail. Destisol was then applied to 37 urban soils under various situations and pedoclimates. The main innovations of Destisol lie in the consideration of soil properties throughout the whole pedon and in the evaluation of the compatibility of the soil with different land covers. It is based on the acquisition of soil indicators, which are transformed into scores of soil functions, then into compatible land covers and finally into scores of ecosystem services. The architecture of the model is based on 20 physico‐chemical‐biological soil indicators used to score 15 soil functions, based on a detailed set of decision rules. The soil functions scores allow the calculation of a percentage of compatibility for 13 land covers. Finally, the resulting scores are used to evaluate 18 ecosystem services, as a function of land cover. The tests show a wide distribution of scores depending on the soil studied, but also depending on the soil function, land cover or ecosystem service considered. Technosols show the largest dispersion of soil function scores, and no correlation was found between the anthropization gradient and the mean soil function score. The main results of Destisol are an assessment of the soil suitability, that is the compatibility between a soil and a land cover, and an explicit assessment of the ecosystem services provided depending on the land covers.

Brazil's riparian forests are continuously threatened by conversion into agricultural areas, causing not only degradation and loss of vegetation but also negative changes in soil properties and ecosystem services. In order to select vegetation and soil variables that are affected by degradation and to evaluate whether forest structure can be used as a proxy for soil ecosystem services, two watersheds in eastern Amazon were chosen as a study area in which four degradation levels were identified (very high, high, moderate and low), based on forest canopy openness and height. Vegetation structural characteristics, water infiltration rates, and soil properties were evaluated in 24, 1,000 m2 permanent plots. Results indicated that forest degradation significantly reduced soil carbon, phosphorus, cation exchange capacity, silt proportion, total porosity, and water content as well as water infiltration rate. Vegetation structure was a good proxy for monitoring soil ecosystem services (i.e. regulation of water flow, erosion control and life‐supporting). Tree height and basal area, as well as herb biomass, were identified as the best vegetation indicators for changes in soil properties that underlie ecosystem services. Application of this strategy may facilitate the monitoring and modeling of riparian forest ecosystem services across broader spatial scales, to help guide efficient restoration efforts and conservation policies. Copyright © 2016 John Wiley & Sons, Ltd.

<p>Desertification is an important soil treat, affecting soil functions and ecosystem services   in arid and semiarid climate zones. Salinization is one of the principal processes which follows desertification and has a negative impact on soil properties and functions. Carbon sequestration is considered a principle soil function and the decline in soil carbon stocks in one of the main negative consequences of soil degradation. Soil salinization is caused by combination of natural factors (e.g. dry climate condition and high table of mineralized ground waters) and human activities such as improper water management. Globally, soils of the areas affected by salinization are considered to be poor in organic carbon due to low biomass and hampered microbiological activity. However, the contribution of inorganic carbon to the total carbon stocks in these areas can be comparable. Considering that soil inorganic carbon is more stable to mineralization compared to organic carbon, soil carbon stocks in saline landscape shall not be neglected.</p><p>Central Asian regions and especially the Aral Sea basin have been historically affected by desertification enhancing soil salinity. Hungry Steppe (Mirzachul) is an area of historical desertification and salinization, covering around 10000 km<sup>2</sup> at the territories of Uzbekistan, South Kazakhstan and Tajikistan. The region has a sharp continental climate with large seasonal fluctuations. Dry and semidesertic steppe vegetation dominates the natural areas (mainly coincided with high soil salinity), whereas most of the areas is managed to produce cotton, perennial grasses, melons and gourds. Soils are dominated by serozems corresponding to Calcisols in WRB soil classification. The research aimed to analyze the effect of salinization on carbon stocks in Hungry Steppe. To achieve this aim, soil carbon stocks were estimated at the four collective farms, referred as Water Consumer Assiociations (WCAs) or ‘shirkats’ in Syrdarya province: Khavast district in Yangier WCA, Mirzaobod district in Beruniy WCA  Oq Oltin district in Andijan WCA and Syrdarya district in Sobir  Rakhimov WCA. The selected sites belonged to different in land quality classes, based on the land evaluation survey carried out by the melioration expedition of the Ministry of Agriculture and Water Resources of Uzbekistan in 201,  from the lowest (Mirzaobod) to the highest (S. Rahimov). Soil pH, electroconductivity, chlorides, organic and inorganic carbon stocks and total nitrogen stocks were estimated for each of the areas. Although the internal variability in the analyzed parameters was high we clearly showed the highest stocks of soil inorganic carbon in the most salinized area, whereas the highest stocks of organic carbon were shown for the most fertile lands. However, we didn’t ding significant difference in the total carbon stocks between the sites. It can be concluded that desertification has more effect on the redistribution of organic and inorganic forms of carbon, rather than on the total carbon stocks.</p><p><strong>Acknowledgements </strong>The experimental research was performed with the support of the Russian Foundation for Basic Research, Project # 18-54-41004 and Ministry of Innovation development of the Republic of Uzbekistan, Project # MRU-SQV 86/2017. Data analysis and mapping was supported by the RUDN project “5-100”.</p>

Soils and their biodiversity are currently being degraded at a rapid pace due to human activities. However, despite sitting at the foundation of human and ecosystem sustainability, soils are often ignored in scientific discussions of global issues. This book synthesizes current knowledge on soil ecosystem services, and provides a basis for the maintenance of soil health and sustainability. It begins by examining the living soil as a habitat in terms of biodiversity, functions, and ecosystem services. Soil ecosystem services are explored and explained at different scales from genes of microbes to whole ecosystems. The book discusses the importance of biodiversity to ecosystem functioning and ecosystem services with regards to phylogeny, biogeography, and diversity of important soil fauna groups, from microbes to large ecosystem engineers. The influence of global environmental changes such as climate change, nutrient enrichment, urbanization, and land use change, and their effect on soils and ecosystem services, are discussed. Finally, the book outlines how sustainability of soils, biodiversity, and ecosystem services can be monitored, maintained, and restored, and how humans, other animals, and ecosystems are dependent on living soils and ecosystem services.

Micro- and nanoplastics in soil: Linking sources to damage on soil ecosystem services in life cycle assessment

Various soil processes are responsible for the flow and maintenance of ecosystems services within a soil type in a landscape. The human-induced pressure causes land degradation like soil erosion, depletion of soil organic matter, loss of soil biodiversity, acidification, mechanical compaction, secondary salinization (from irrigation water) and contamination by industrial wastes. These degradations are damaging the capacity of soil to perform optimum soil functions. Soil erosion is the major cause of land degradation which causes huge losses to the economy through loss of provisioning, regulating, and supporting ecosystem services (ESs). Study revealed that global economic losses from soil erosion is around US $ 8 billion annually, due to reduced soil fertility, decreased crop yields and increased water usage. However, proper implementation of soil and water conservation (SWC) measures and sediment control programmes can reduce the erosion and sediment loads of water bodies. Soil conservation measures are sustainable if the supporting, provisioning, regulating, and cultural ecosystem services provided by soil are maintained or enhanced without significantly impairing the soil functions. In this chapter, for easy understanding, some important soil functions are compared for two contrasting ecosystems at three different locations within a landscape in hill and mountain ecosystem of India. Overall, the aggregated soil quality was better in adjoining forest sites than that of terraced croplands. It clearly showed that to maximize the crop productivity through intensive cultivation, there is massive compromise with the soil ecosystem functions. We highlighted here that in hill and mountain ecosystem, land use land cover change through legume intercropping in maize had the highest additional ESs to the tune of USD 457 (INR. 33637) compared to without inter cropping. Interestingly, here the contribution of regulating service was more (to the tune of USD 241; INR. 17735) than the provisioning service (USD 210; INR. 15461). The analysis of different parameters in a participatory watershed management study revealed that the ecosystem benefits due to soil and water conservation intervention in a watershed can be realized by understanding the saving of travel time for odder and fuel collection, soil retention through erosion control, nutrient build-up and carbon sequestration. Earlier (before the watershed intervention) the women community used to travel to near-by forest areas for the purpose of collecting fuel-woods and fodder. After 27 years, they realized the importance of soil and water conservation intervention in terms of many provisioning and intangible benefits. Although, more detail information and computation methodology needs to be established to compute the all other benefits. Soil degradation is a severe global concern for food security and ecosystem sustainability due to landslides, erosion, and a reduction in soil carbon and biodiversity. Soils' contribution to human well-being goes beyond food production, and this may be addressed by incorporating soils into the ecosystem services framework and linking it to the diverse functions it performs. Much research has been done on soil and ecosystem services, but not all of them have looked at the direct relationship between soil qualities and ecosystem services.