scholarly journals Sediment Phosphorus Release in Boreal Lakes: The Role of Trophic State and Humic Substances

2021 ◽  
Author(s):  
Olga Tammeorg ◽  
Gertrud Nürnberg ◽  
Peeter Nõges ◽  
Juha Niemistö
Keyword(s):  
Humic Substances ◽  
Trophic State ◽  
Organic Matter Content ◽  
Boreal Lakes ◽  
Reverse Direction ◽  
Internal P Loading ◽  
Multiple Stressor ◽  
P Release ◽  
P Fraction ◽  
The Impact

Abstract Coloured lakes are often productive. While their increased productivity can be the consequence of internal recycling of phosphorus (P), the impact of humic substances on these interactions is largely unexplored. Here we elucidated the spatial variations in sediment P release by diffusion in four Finnish lakes with high trophic state. For further insights regarding possible implications of humic substances on sediment P release, we extended our analysis to lakes worldwide using data from the scientific literature. Variations in sediment P release rates (RR) in four Finnish lakes were largely explained by trophic state and mixing state of the water column. P release by diffusion was positively correlated with the iron-bound P fraction, but negatively with the organic-P fraction in surface sediment. Furthermore, the diffusive flux of P correlated positively with the RR predicted from a published model based on total P concentration (positive effect) and organic matter content (negative effect) in surface sediments. Analysis of the worldwide data confirmed the importance of humic substances in internal P recycling. While dissolved organic carbon (DOC) in water correlated positively with RR in oligotrophic lakes, the correlation was negative in lakes of higher trophic state. The implications for internal P loading and primary production, however, are not so straightforward. In a multiple-stressor world (climate change, eutrophication), response of internal P load in boreal lakes to changes in DOC is particularly unpredictable. This is because the variables relevant to internal P loading, i.e. RR and anoxic factor, may be affected in a reverse direction.

NOM increase in drinking water reservoirs - relevance for drinking water production

2004 ◽  
Vol 4 (4) ◽  
pp. 55-60 ◽  
Author(s):  
A. Korth ◽  
C. Fiebiger ◽  
K. Bornmann ◽  
W. Schmidt
Keyword(s):  
Molecular Weight ◽  
Drinking Water ◽  
Humic Substances ◽  
Elimination Rate ◽  
Organic Matter Content ◽  
Matter Content ◽  
Water Reservoirs ◽  
Treated Water ◽  
Drinking Water Production ◽  
The Impact

In the last 10–15 years in some German drinking water reservoirs an increase in the NOM (natural organic matter) content has occurred. The impact of such a change on the drinking water quality was almost unknown. A research project was carried out at several drinking water reservoirs and water works concerning the change in the NOM quality and the nutrient situation. The results indicate that the NOM increase in the reservoir is predominately caused by an increasing input of high and intermediate molecular weight humic substances from the catchment area into the reservoir. The fractions of the polysaccharides and the high molecular weight humic substances are significantly reduced in the treatment process. In contrast, the elimination rate for the substances with an intermediate and low molecular weight was low. Due to the low elimination rate particularly of the intermediate humic fraction, the NOM content of the treated water increased with the change in the raw water. Furthermore, the BDOC of the treated water increased with the NOM content. For the AOC of the treated water no relationship was found with the NOM content. However, the change of this parameter was affected by the snowmelt and the circulation in the reservoir.

scholarly journals Fruit yield and composition in orange trees cv. 'Lane Late' in response to nitrogen fertilization in Sandy Typic Hapludalf soil

2017 ◽  
Vol 47 (3) ◽  
Author(s):  
Gustavo Brunetto ◽  
◽  
Cesar Cella ◽  
Alcione Miotto ◽  
Eduardo Girotto ◽  
...  
Keyword(s):  
Fruit Juice ◽  
Organic Matter Content ◽  
Titratable Acidity ◽  
N Fertilization ◽  
Fruit Yield ◽  
Soluble Solids ◽  
Total N ◽  
Total Titratable Acidity ◽  
Orange Trees ◽  
The Impact

ABSTRACT: Little is known about the impact of N fertilization on fruit production and composition in orange groves grown in soils with low or medium organic matter content in Rio Grande do Sul (RS). This study aimed to evaluate how N fertilization of orange trees cv. 'Lane Late' in a sandy soil may interfere in fruit yield and composition of fruit and juice. The experiment was conducted with orange trees cv. 'Lane Late' growing in Sandy Typic Hapludalf soil, in Rosário do Sul (RS). The plants received applications of 0, 20, 40, 60, 80, 100, 120, 140 and 160kg N ha-1. Total N in leaves, number of fruits per plant, yield, fresh weight, fruit diameter, peel thickness, percentage of fruit juice, peel color, juice color, ascorbic acid content, total soluble solids (TSS) and total titratable acidity were evaluated in 2010/2011 and 2011/2012 crops. In the first crop, especially yield, number of fruits per plant, TSS content in fruit juice and ratio decreased with increasing N rate applied. However, in the second crop, the total titratable acidity of the fruit juice prominently increased with the dose of N applied. In both crops, results were highly influenced by rainfall distribution, which affect the plant physiology, soil N dynamics and, consequently, probability of response to N applied and the loss of mineral N in the soil.

scholarly journals Differences in soil organic matter and humus of sandy soil after application of biochar substrates and combination of biochar substrates with mineral fertilizers

2020 ◽  
Vol 23 (3) ◽  
pp. 117-124
Author(s):  
Dušan Šrank ◽  
Vladimír Šimanský
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Carbon Content ◽  
Humic Substances ◽  
Sandy Soil ◽  
The Other ◽  
Mineral Fertilizers ◽  
Other Hand ◽  
Sheep Manure ◽  
The Impact

The effort to achieve the sustainable farming system in arable soil led to the intensive search for a new solution but an inspiration can also be found in the application of traditional methods of soil fertility improvement as it is shown in numerous examples in history. Recently many scientific teams have focused their attention on the evaluation of biochar effects on soil properties and crop yields. Since there are a lot of knowledge gaps, especially in explanations how biochar can affect soil organic matter (SOM) and humus substances, we aimed this study at the solution of these questions. Therefore, the objective of the experiment was to evaluate the impact of two biochar substrates (B1 – biochar blended with sheep manure, and B2 – biochar blended with sheep manure and the residue from the biogas station) at two rates (10 and 20 t ha-1) applied alone or in combination with mineral fertilizers (Urea was applied in 2018, at rate 100 kg ha-1, and Urea at rate 100 kg ha-1 + AMOFOS NP 12-52 at 100 kg ha-1 were applied in 2019) on the quantity and quality of SOM and humus of sandy soil (Arenosol, Dolná Streda, Slovakia). The results showed that application of the biochar substrates together with mineral fertilizers (MF) had more pronounced effect on the organic matter mineralization in the sandy soil which resulted in low accumulation of soil organic carbon (Corg) and labile carbon compared to biochar substrates treatments without MF. The share of humic substances in Corg significantly decreased by 16, 50, 16 and 24% in B1 at 10 t ha-1, B1 at 20 t ha-1, B2 at 10 t ha-1 and B2 at 20 t ha-1 treatments, respectively, compared to the control. A similar tendency was observed for biochar substrates treatments + MF, compared to MF control. The carbon content of humic substances (CHS) was equal to 4.40 – 5.80 g kg-1 and the biochar substrates had statistically significant influence on CHS content. On average, there was a smaller decrease of CHS in B1 at rate 10 t ha-1 than at rate 20 t ha-1 and no effect of B2 compared to control. The carbon content of fulvic acid (CFA) was 9% higher in B1 at 10 t ha-1, and 20 t ha-1, 47% higher in B2 at 10 t ha-1 and 17% higher in B2 at 20 t ha-1 compared to control. As a result of biochar substrates + MF application, the reduction in CFA was observed. The results showed a decrease of CHA : CFA ratio with association to biochar substrates alone application compared to control on one hand, and a wider of CHA : CFA ratio in biochar substrates + MF treatments in comparison to MF control on the other hand. Humus stability was increased in biochar substrates alone treatments compared to control, on the other hand, compared to MF control, the application of biochar substrates + MF resulted in a lower humus stability.

scholarly journals ECOTOXICOLOGICAL ASSESSMENT OF THE SOILFERTILIZED WITH SEWAGE SLUDGE

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Justyna Kujawska ◽  
Katarzyna Wójcik-Oliveira
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Control Measure ◽  
Organic Matter Content ◽  
Environmental Safety ◽  
Matter Content ◽  
Ecotoxicological Assessment ◽  
Safety Control ◽  
The Impact ◽  
Modified Soil

Sewage sludge and its management constitute one of the most important environmental problems. The introduced the Sewage Sludge Directive 86/278/EEC advocate utilization of sewage sludge in agriculture. However, this method is limited mainly by the availability of heavy metals and pathogens. An ecotoxicological assessment of sewage sludge doses applied to soil, recommended in the Polish Regulation of the Minister of Environment of 6th February 2015 on municipial sewage sludge, was carried out. The sewage sludge was added to soil in the amounts of 3, 6, 9, and 15 Mg/ha. The produced mixtures were subjected to physicochemical and ecotoxicological tests, involving the biomass and mortality tests of Eisenia fetida earthworms. The sewage sludge had a statistically significant impact on the increase in: electrical conductivity, total exchangeable cations, organic matter content, organic carbon, nitrogen and heavy metals of the considered soil. The impact on the biomass of earthworms was different; after 7 days in the mixtures with 3 Mg/ha and 6 Mg/ha sewage sludge addition, the biomass increased approximately by 1.3-fold, in comparison to non-modified soil. At 9 Mg/ha, it reduced by 1.3-fold, whereas at 15 Mg/ha – by 16-fold, in relation to the initial value. The studies indicated that the ecotoxicological assessment of wastes may be employed as environmental safety control measure of the sewage sludge application in agriculture.

scholarly journals Role of humic substances as refractory organic matter in sustainable water quality assessment and management

2019 ◽  
Vol 20 (2) ◽  
pp. 538-549
Author(s):  
Maoqing Duan ◽  
Xia Du ◽  
Wenqi Peng ◽  
Cuiling Jiang ◽  
Shijie Zhang
Keyword(s):  
Water Quality ◽  
Chemical Oxygen Demand ◽  
Humic Substances ◽  
River Water ◽  
Anthropogenic Activities ◽  
Water Quality Management ◽  
National Development ◽  
Oxygen Demand ◽  
Study Results ◽  
The Impact

Abstract In northern China, river water originating from or flowing through forests often contains large amounts of oxygen-consuming organic substances, mainly humic substances. These substances are stable and not easily biodegradable, resulting in very high detection values of chemical oxygen demand. However, under natural conditions, the dissolved oxygen demand is not as high. Using experimental values to evaluate river water quality and the impact of human activities on water quality is thus unscientific and does not meet national development goals. In this study, the potential sources of high-concentration chemical oxygen demand in river water in two areas exposed to virtually no anthropogenic activities and strongly affected by humic substances, were analysed. The chemical oxygen demand contributed by humic substances (COD-HSs) was quantified using three methods. The results of water quality monitoring in 2017 and 2018 revealed that the chemical oxygen demand concentrations (5–44 mg/L) predominantly exceeded the standard (15 mg/L). The study results suggest that COD-HSs should be considered separately for objective evaluation and management of water quality, particularly in areas that are seriously affected by COD-HSs, to provide a scientific basis for formulating sustainable water quality management policies.

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