Assessing Impacts on the Natural Resource Soil in Life Cycle Assessment: Methods for Compaction and Water Erosion

Development of a Multifaceted Perspective for Systematic Analysis, Assessment, and Performance for Environmental Standards of Contaminated Sites

Contaminated soil and groundwater can pose significant risks to human health and ecological environments, making the remediation of contaminated sites a pressing and sustained challenge. It is significant to identify key performance indicators and advance environmental management standards of contaminated sites. The traditional study currently focuses on the inflexible collection of related files and displays configurable limitations regarding integrated assessment and in-depth analysis of published standards. In addition, there is a relative lack of research focusing on the analysis of different types of standard documents. Herein, we introduce a cross-systematic retrospective and review for the development of standards of the contaminated sites, including the comprehensive framework, multifaceted analysis, and improved suggestion of soil and groundwater standards related to the environment. The classification and structural characteristics of different types of files are systematically analyzed of over 300 national, trade, local, and group standards for the contaminated sites. It exhibits that trade standards are the main types and testing methods are the important format within numerical considerations of soil standards. The guide standard serves as a crucial component in environmental management for investigating, assessing, and remediating of contaminated sites. Future improvement plans and development directions are proposed for advancing robust technical support for effective soil contamination prevention and control. This multidimensional analysis and the accompanying suggestions can provide improved guidance for Chinese environmental management of contaminated sites and sparkle the application of standards in a wide range of countries.

Quantifying the contribution of direct runoff and baseflow to nitrogen loading in the Western Lake Erie Basins

Soluble nitrogen is highly mobile in soil and susceptible to leaching. It is important to identify nitrogen transport pathways so that the sources can be efficiently targeted in environment management. This study quantified the contribution of direct runoff and baseflow to nitrate + nitrite loading by separating flow and nitrate + nitrite concentration measurements into two periods depending on whether only baseflow was present or not using baseflow separation methods. When both direct runoff and baseflow were present in streamflow, their nitrate + nitrite concentrations were assumed based on the hydrological reasoning that baseflow does not change rapidly, and streamflow mostly consists of direct runoff within a rainfall event. For this study, we obtained and investigated daily flow and nitrate + nitrite concentration observations made at the outlets of 22 watersheds located in the Western Lake Erie area. Results showed that baseflow was responsible for 26 to 77% of the nitrate + nitrite loads. The relative nitrate + nitrite load contributions of direct runoff and baseflow substantially varied with the sizes of drainage areas and agricultural land uses. Increases in drainage areas tend to prolong the travel time of surface runoff and thus help its reinfiltration into soil, which then could increase the baseflow contribution. In addition, the artificial drainage networks common in the agricultural fields of the study areas would promote the drainage of nutrient-laden excess water from soils. Such findings suggest the need for environmental management customized considering nitrogen transport pathways.

Farm vehicles approaching weights of sauropods exceed safe mechanical limits for soil functioning

Mechanization has greatly contributed to the success of modern agriculture, with vastly expanded food production capabilities achieved by the higher capacity of farm machinery. However, the increase in capacity has been accompanied by higher vehicle weights that increase risks of subsoil compaction. We show here that while surface contact stresses remained nearly constant over the course of modern mechanization, subsoil stresses have propagated into deeper soil layers and now exceed safe mechanical limits for soil ecological functioning. We developed a global map for delineating subsoil compaction susceptibility based on estimates of mechanization level, mean tractor size, soil texture, and climatic conditions. The alarming trend of chronic subsoil compaction risk over 20% of arable land, with potential loss of productivity, calls for a more stringent design of farm machinery that considers intrinsic subsoil mechanical limits. As the total weight of modern harvesters is now approaching that of the largest animals that walked Earth, the sauropods, a paradox emerges of potential prehistoric subsoil compaction. We hypothesize that unconstrained roaming of sauropods would have had similar adverse effects on land productivity as modern farm vehicles, suggesting that ecological strategies for reducing subsoil compaction, including fixed foraging trails, must have guided these prehistoric giants.

Soil water infiltration evaluation from punctual to hillslope scales

Quantifying infiltration and surface runoff at the hillslope scale is indispensable for soil conservation studies. However, the spatial and temporal variability of infiltration imposes a major constraint on surface runoff estimation. Point infiltration values do not fully express the complexity of the surface runoff in the landscape. Considering the need to improve the estimation of runoff volume from infiltration data, this study aimed to measure the apparent infiltration at hillslope-scale and compare it with two methods of infiltration estimative derived from point information. The study was carried out in six hydrological monitoring units paired. A set of hyetographs and hydrographs allowed the determination of apparent infiltration [Formula: see text] to each monitoring unit as a function of precipitation rate P. The measured [Formula: see text] values were used: (1) to evaluate the efficiency of the different land management in increasing infiltration; and (2) to evaluate the efficiency of two methods of hillslope-scale infiltration estimation based on point data: (a) derived from concentric rings method ([Formula: see text]), and (b) derived from a physically-based modeling ([Formula: see text]). Regarding the differences in land managements, terraces proved to be the most efficient land management practice, followed by phytomass addition. Regarding the methods, for precipitation rates greater than 40 [Formula: see text] the point infiltration-based [Formula: see text] underestimates apparent infiltration [Formula: see text] with PBIAS ranging from [Formula: see text] to [Formula: see text]. Even so, [Formula: see text] proved efficient in representing [Formula: see text] at less intense rainfall events. Nonetheless, the point infiltration-based method [Formula: see text] properly represented [Formula: see text] to all rainfall intensities (Nash-Sutcliffe coefficient [Formula: see text]).

Global Assessment of Agricultural Productivity Losses from Soil Compaction and Water Erosion

To guide us toward a sustainable future, the impacts of human activities on natural resources need to be understood and quantified. In this study on global agriculture, we use a Life Cycle Assessment framework to estimate potential long-term soil productivity losses caused by soil compaction and water erosion due to agricultural crop production. We combine several data sets to model spatially resolved Life Cycle Inventory information at the global level and multiply results with characterization factors from a previous publication. The global picture shows a compaction-stressed "Global North" and an erosion-stressed "Global South", with some countries and regions in between, for example, China and parts of South America. Results show that both compaction and water erosion impacts matter at the global level and that overall potential long-term productivity losses of 10-20% can be expected, with high relative impacts on low input production systems. These losses might limit long-term agricultural productivity and lead to additional land use change. Our work adds to and extends the discussion of global assessments of soil degradation. Furthermore, we prove the suggested framework to be applicable and useful for Life Cycle Assessments and other studies and provide results that can be used in such global assessments.

Life cycle assessment (LCA): informing the development of a sustainable circular bioeconomy?

The role of life cycle assessment (LCA) in informing the development of a sustainable and circular bioeconomy is discussed. We analyse the critical challenges remaining in using LCA and propose improvements needed to resolve future development challenges. Biobased systems are often complex combinations of technologies and practices that are geographically dispersed over long distances and with heterogeneous and uncertain sets of indicators and impacts. Recent studies have provided methodological suggestions on how LCA can be improved for evaluating the sustainability of biobased systems with a new focus on emerging systems, helping to identify environmental and social opportunities prior to large R&D investments. However, accessing economies of scale and improved conversion efficiencies while maintaining compatibility across broad ranges of sustainability indicators and public acceptability remain key challenges for the bioeconomy. LCA can inform, but not by itself resolve this complex dimension of sustainability. Future policy interventions that aim to promote the bioeconomy and support strategic value chains will benefit from the systematic use of LCA. However, the LCA community needs to develop the mechanisms and tools needed to generate agreement and coordinate the standards and incentives that will underpin a successful biobased transition. Systematic stakeholder engagement and the use of multidisciplinary analysis in combination with LCA are essential components of emergent LCA methods. This article is part of the theme issue 'Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 1)'.