Integrated climate-chemical indicators of diffuse pollution from land to water

Management of agricultural diffuse pollution to water remains a challenge and is influenced by the complex interactions of rainfall-runoff pathways, soil and nutrient management, agricultural landscape heterogeneity and biogeochemical cycling in receiving water bodies. Amplified cycles of weather can also influence nutrient loss to water although they are less considered in policy reviews. Here, we present the development of climate-chemical indicators of diffuse pollution in highly monitored catchments in Western Europe. Specifically, we investigated the influences and relationships between weather processes amplified by the North Atlantic Oscillation during a sharp upward trend (20102016) and the patterns of diffuse nitrate and phosphorus pollution in rivers. On an annual scale, we found correlations between local catchment-scale nutrient concentrations in rivers and the influence of larger, oceanic-scale climate patterns defined by the intensity of the North Atlantic Oscillation. These influences were catchment-specific showing positive, negative or no correlation according to a typology. Upward trends in these decadal oscillations may override positive benefits of local management in some years or indicate greater benefits in other years. Developing integrated climate-chemical indicators into catchment monitoring indicators will provide a new and important contribution to water quality management objectives

Internet of Things for Water Sustainability

The water is a finite resource. The issue of sustainable withdrawal of freshwater is a vital concern being faced by the community. There is a strong connection between the energy, food, and water which is referred to as water-food-energy nexus. The agriculture industry and municipalities are struggling to meet the demand of water supply. This situation is particularly exacerbated in the developing countries. The projected increase in world population requires more fresh water resources. New technologies are being developed to reduce water usage in the field of agriculture (e.g., sensor guided autonomous irrigation management systems). Agricultural water withdrawal is also impacting ground and surface water resources. Although the importance of reduction in water usage cannot be overemphasized, major efforts for sustainable water are directed towards the novel technology development for cleaning and recycling. Moreover, currently, energy technologies require abundant water for energy production. Therefore, energy sustainability is inextricably linked to water sustainability. The water sustainability IoT has a strong potential to solve many challenges in water-food-energy nexus. In this chapter, the architecture of IoT for water sustainability is presented. An in-depth coverage of sensing and communication technologies and water systems is also provided

Particulate-facilitated leaching of glyphosate and phosphorus from a marine clay soil via tile drains

Losses of commonly used chemical pesticides from agricultural land may cause serious problems in recipient waters in a similar way to phosphorus (P). Due to analytical challenges concerning determination of glyphosate (Gly), transport behaviour of this widely used herbicide is still not well-known. The objective of the present study was to quantify and evaluate leaching of Gly in parallel with P. Leaching losses of autumn-applied Gly (1.06 kg ha-1) via drainage water were examined by flow-proportional sampling of discharge from 20 drained plots in a field experiment in eastern Sweden. Samples were analysed for Gly in particulate-bound (PGly) and dissolved (DGly) form. The first 10 mm water discharge contained no detectable Gly, but the following 70 mm had total Gly (TotGly) concentrations of up to 6 µg L-1, with 62% occurring as PGly. On average, 0.7 g TotGly ha-1 was leached from conventionally ploughed plots, compared with 1.7 g TotGly ha-1 from shallow-tilled plots (cultivator to 12 cm working depth). Higher Gly losses occurred in snowmelt periods in spring, but then with the majority (60%) as DGly. All autumn concentrations of PGly in drainage water were significantly correlated (p<0.001) to the concentrations of particulate-bound phosphorus (PP) lost from the different plots (Pearson correlation coefficient 0.84), while PP concentrations were in turn significantly correlated to water turbidity (Pearson correlation coefficient 0.81). Leaching losses of TotGly were significantly lower (by 1.3 g ha-1; p<0.01) from plots that had been structure-limed three years previously and ploughed thereafter than from shallow-tilled plots. Turbidity and PP concentration also tended to be lowest in discharge from structure-limed plots and highest from shallow-tilled plots. This difference in TotGly leaching between soil management regimes could not be explained by differences in measured pH in drainage water or amount of discharge. However, previously structure-limed plots had significantly better aggregate stability, measured as readily dispersed clay (RDC), than unlimed plots. The effects of building up good soil structure, with strong soil aggregates and an appropriate pore system in the topsoil, on mitigating Gly and P losses in particulate and dissolved form should be further investigated

Phosphorus Availability in Soils Amended with Wheat Residue Char

Plant availability and risk for leaching and/or runoff losses of phosphorus (P) from soils depends among others on P concentration in the soil solution. Water soluble P in soil measures soil solution P concentration. The aim of this study was to understand the effect of wheat residue char (biochar) addition on water soluble P concentration in a wide range of biochar amended soils. Eleven agricultural fields representing dominant soil texture classes of Swedish agricultural lands were chosen. Concentrations of water soluble P in the soils and in biochar were measured prior to biochar incorporation to soils in the laboratory. Experiments with three dominant soil textures- silt loam, clay loam and an intermediate loam soil with different rates of biochar addition (i.e., 0.5, 1, 2 and 4%; w/w) showed that the highest concentration of water soluble P was achieved at an application rate of 1%. At higher application rates, P concentrations decreased which coincided with a pH increase of 0.3 - 0.7 units. When the eleven soils were amended with 1% (w/w) biochar, water soluble P concentrations increased in most of the soils ranging from 11 to 253%. However, much of the water soluble P added through the biochar was retained (33 - 100%). We concluded that - wheat residue char can act as a source of soluble P; and low and high additions of biochar can have different effects on soil solution P concentration due to possible reactions with Ca and Mg added with biochar