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In this paper, we present the Daily based Morgan-Morgan-Finney model. The main processes in this model are based on the Morgan-Morgan-Finney soil erosion model, and it is suitable for estimating surface runoff and sediment redistribution patterns in seasonal climate regions with complex surface configurations. We achieved temporal flexibility by utilizing daily time steps, which is suitable for regions with concentrated seasonal rainfall. We introduce the proportion of impervious surface cover as a parameter to reflect its impacts on soil erosion through blocking water infiltration and protecting the soil from detachment. Also, several equations and sequences of sub-processes are modified from the previous model to better represent physical processes. From the sensitivity analysis using the Sobol' method, the DMMF model shows the rational response to the input parameters which is consistent with the result from the previous versions. To evaluate the model performance, we applied the model to two potato fields in South Korea that had complex surface configurations using plastic covered ridges at various temporal periods during the monsoon season. Our new model shows acceptable performance for runoff and the sediment loss estimation (NSE⩾0.63, jPBIASj ⩽17.00, and RSR ⩽ 0.57). Our findings demonstrate that the DMMF model is able to predict the surface runoff and sediment redistribution patterns for cropland with complex surface configurations. [ABSTRACT FROM AUTHOR]

Non-sustainable agricultural practices can alter the quality of soil and water. A sustainable soil management requires detailed understanding of how tillage affects soil quality, erosion, and leaching processes. Agricultural soils in the Haean catchment (South Korea) are susceptible to erosion by water during the monsoon. For years, erosion-induced losses have been compensated by spreading allochthonous sandy material on the fields. These anthropogenically modified soils are used for vegetable production, and crops are cultivated in ridges using plastic mulches. To evaluate whether the current practice of ridge cultivation is sustainable with regard to soil quality and soil and water conservation, we (i) analysed soil properties of topsoils and (ii) carried out dye tracer experiments. Our results show that the sandy topsoils have a very low soil organic matter content and a poor structure and lack soil burrowers. The artificial layering induced by spreading sandy material supported lateral downhill water flow. Ridge tillage and plastic mulching strongly increased surface runoff and soil erosion. We conclude that for this region a comprehensive management plan, which aims at long-term sustainable agriculture by protecting topsoils, increasing soil organic matter, and minimizing runoff and soil erosion, is mandatory for the future. [ABSTRACT FROM AUTHOR]

• We assess interregional flows of four ecosystem services used in Germany. • Germany´s prosperity depends on ecosystem services supplied abroad. • Governance mechanisms need to operate at multiple scales. Despite a growing number of national-scale ecosystem service (ES) assessments, few studies consider the impacts of ES use and consumption beyond national or regional boundaries. Interregional ES flows – ecosystem services "imported" from and "exported" to other countries – are rarely analyzed and their importance for global sustainability is little known. Here, we provide a first multi-ES quantification of a nation's use of ES from abroad. We focus on ES flows that benefit the population in Germany but are supplied outside German territory. We employ a conceptual framework recently developed to systematically quantify interregional ES flows. We address four types of interregional ES flows with: (i) biophysical flows of traded goods: cocoa import for consumption; (ii) flows mediated by migratory species: migration of birds providing pest control; (iii) passive biophysical flows: flood control along transboundary watersheds; and (iv) information flows: China's giant panda loan to the Berlin Zoo. We determined that: (i) Ivory Coast and Ghana alone supply around 53% of Germany's cocoa while major negative consequences for biodiversity occurred in Cameroon and Ecuador; (ii) Africa´s humid and sub-humid climate zones are important habitats for the majority of migratory bird species that provide natural pest control services in agricultural areas in Germany; (iii) Upstream watersheds outside the country add an additional 64% flood regulation services nationally, while Germany exports 40% of flood regulation services in neighboring, downstream countries; (iv) Information flows transported by the pandas were mainly related to political aspects and - contrary to our expectations - considerably less on biological and natural aspects. We discuss the implications of these results for international resource management policy and governance. [ABSTRACT FROM AUTHOR]

Abstract: Intensive agricultural land use in combination with heavy rain storm events during the summer monsoon season plays a key role in groundwater pollution by nutrients and agrochemicals in agricultural catchments in South Korea. A widespread measure for weed control in this region is plastic mulched ridge cultivation. However, it is not well understood, how and to which extent the water flow regime in sloped fields is hereby modified. To evaluate the effect of plastic mulched ridge cultivation (RTpm) on soil water dynamics, we carried out a two-dimensional process-based modeling study using the numerical model Hydrus 2/3D. Subsequently, RTpm was compared to model simulations of ridge cultivation without plastic cover (RT) and flat conventional tillage without ridges and without plastic cover (CT). Datasets of soil water potentials obtained by field measurements at two plastic mulched potato fields (Solanum tuberosum L.) provided the basis for optimizing soil hydraulic parameters inversely by the Levenberg–Marquardt algorithm. We found, that plastic mulching induced horizontal pressure head gradients and forced soil water to move laterally from furrows to ridges under normal weather conditions. During monsoon events, soils were fully saturated and interflow occurred in coarse textured and ploughed topsoil. Further, the water balance of the different model scenarios showed that plastic mulching reduced drainage water up to 16% but concurrently increased the surface runoff up to 65%. The consequences are an increase in runoff peak flow, flood risk and erosion. Therefore, we recommend the application of perforated and biodegradable plastic mulch in regions affected by summer monsoon. [Copyright &y& Elsevier]

Intensive agricultural practices implemented to secure increased crop yields have potentially negative environmental effects due to the generation of sediment and nutrients from agricultural fields. The monsoon climate and current agricultural practices on mountainous landscapes of the Haean catchment in South Korea have significantly affected water quality by transporting sediment and nutrients to downstream water bodies. The aim of this study is to suggest strategies for a permanent reduction of sediment and nitrate from this catchment through an efficient application of best management practices (BMPs). We applied three BMPs; split fertilizer application (SF), winter cover crop cultivation (CC), and a combination of the two (SFCC) to major dryland crops (cabbage, potato, radish and soybean) in order to investigate their effectiveness at the catchment scale through the Soil and Water Assessment Tool (SWAT) model. We found that the SF scenario reduced nitrate pollution while sediment and crop yield did not change relative to the baseline (BL) scenario. The application of the CC scenario reduces both sediment and nitrate load while crop yields increased. The combination of split fertilization and cover cropping (SFCC) showed the highest positive effect on reducing sediment and nitrate and increasing crop yields compared to a single application. We estimated the variability in the effectiveness of BMPs for major crop types and could demonstrate that specific sites and crop types, such as soybean, were less influential in reducing sediment and nitrate loads. Those sites and crops could be considered for additional BMP measures to mitigate water deterioration by target pollutants. Recommendations for BMP applications should also consider minor crops and other land use types in order to reduce overall water pollution and efficiently improve crop yields in this catchment. [ABSTRACT FROM AUTHOR]

Peatlands perform important ecosystem functions, such as carbon storage and nutrient retention, which are affected, among other factors, by vegetation and peat decomposition. The availability of silicon (Si) in peatlands differs strongly, ranging from <1 to >25 mg L -1 . Since decomposition of organic material was recently shown to be accelerated by Si, the aim of this study was to examine how Si influences decomposition of carbon and nutrient and toxicant mobilization in peatlands. We selected a fen site in Northern Bavaria with naturally bioavailable Si pore water concentrations of 5 mg/L and conducted a Si addition experiment. At a fourfold higher Si availability, dissolved organic carbon, carbon dioxide, and methane concentrations increased significantly. Furthermore, dissolved nitrogen, phosphorus, iron, manganese, cobalt, zinc, and arsenic concentrations were significantly higher under high Si availability. This enhanced mobilization may result from Si competing for binding sites but also from stronger reducing conditions, caused by accelerated respiration. The stronger reducing conditions also increased reduction of arsenate to arsenite and thus the mobility of this toxicant. Hence, higher Si availability is suggested to decrease carbon storage and increase nutrient and toxicant mobility in peatland ecosystems.