Complex interactions of in-stream DOM and nutrient spiralling unravelled by Bayesian regression analysis

2021 ◽  
Author(s):  
Matthias Pucher ◽  
Peter Flödl ◽  
Daniel Graeber ◽  
Klaus Felsenstein ◽  
Thomas Hein ◽  
...  
Keyword(s):  
Nutrient Uptake ◽  
Nutrient Dynamics ◽  
Gas Production ◽  
Transport Processes ◽  
Bayesian Regression ◽  
Nutrient Concentrations ◽  
Cow Dung ◽  
Small Stream ◽  
Fluorescence Measurements ◽  
Nutrient Spiralling

<p>The carbon cycle in aquatic environments is of high interest because of its effects on water quality and greenhouse gas production as well as its alteration through anthropogenic activities with unknown outcomes. Uptake and release of dissolved organic matter (DOM) compounds is depending on the molecular structure and is strongly linked to N and P dynamics. Current research has not fully revealed the complex patterns behind.</p><p>To investigate the interactions between DOM components, we performed ten plateau addition experiments with different, realistic, complex DOM leachates (cow dung, pig dung, corn, leaves and nettles) in a small stream. The DOM quality was determined by fluorescence measurements and parallel factor (PARAFAC) decomposition and the nutrient concentrations were measured at eleven consecutive points in the stream at plateau conditions. The hydrological transport processes were incorporated by using the results of a 1-D hydrodynamic model.</p><p>The nutrient spiralling concept and its application in nutrient dynamics is a valuable basis for the analysis of our data. However, we could not find a data analysis approach, that suited the nature of our questions and data. Based on previously observed nutrient uptake models, we extended the nutrient spiralling concept by additional non-linear terms to analyse interactions between different DOM components.</p><p>We developed the “Interactions in Nutrient Spirals using BayesIan REgression (INSBIRE)” approach to analyse DOM uptake and retention mechanism. This approach can disentangle complex and interacting biotic and abiotic drivers in nutrient uptake metrics, show their variability and quantify their error distribution. We successfully used INSBIRE to show DOM-compound-specific interactions and draw conclusions from the data of our experiment. The applicability of INSBIRE has still to be tested in other studies, but we see a high potential not only in DOM dynamics but any kind of solute dynamics where interactions are crucial.</p>

scholarly journals Complex interactions of in-stream DOM and nutrient spiralling unravelled by Bayesian regression analysis

2020 ◽  
Author(s):  
Matthias Pucher ◽  
Peter Flödl ◽  
Daniel Graeber ◽  
Klaus Felsenstein ◽  
Thomas Hein ◽  
...  
Keyword(s):  
Nitrate Uptake ◽  
Soluble Reactive Phosphorus ◽  
Transport Processes ◽  
Bayesian Regression ◽  
Nutrient Concentrations ◽  
Small Stream ◽  
Fluorescence Measurements ◽  
Wide Range ◽  
Non Linear ◽  
Nutrient Spiralling

Abstract. Uptake and release patterns of dissolved organic matter (DOM) compounds and nutrients are entangled, and the current literature does not provide a consistent picture of the link between DOM composition, nutrient concentrations, and effects on their cycling. We performed two plateau addition experiments for each of five different, realistic, complex DOM leachates in a small stream, heavily enriched in nitrate but not phosphate or DOM due to diffuse agricultural pollution. By including cow and pig dung as well as corn, leaves and nettles leachates, the study used a wide range of different DOM qualities. We measured changes in nutrient concentrations and determined DOM fractions by fluorescence measurements and parallel factor (PARAFAC) decomposition. To assess influences from hydrological transport processes, we used a 1-D hydrodynamic model. We propose a non-linear Bayesian approach to the nutrient spiralling concept, the Interactions in Nutrient Spirals using BayesIan REgression (INSBIRE) approach. This approach can disentangle complex and interacting biotic and abiotic drivers in nutrient uptake metrics, show their variability and quantify their error distribution. Furthermore, previous knowledge on nutrient spiralling can be included in the model using prior probability distributions. We used INSBIRE to assess interactions of compound-specific DOM and nutrient spiralling metrics the data of our experiment. The uptake processes of different DOM fractions were linked to each other. We observed stimulating and dampening effects of DOM fractions on each other and the overall DOM uptake. We found saturation effects for dissolved organic carbon (concentration of C, DOC) uptake, as rising concentrations of a DOM fraction dampened its uptake. The degradation of a humic DOM component of terrestrial origin was stimulated by other DOM fractions, pointing to priming effects. We also found an influence of the wetted width on the uptake of soluble reactive phosphorus (SRP) and a microbially derived humic substance, which indicates the importance of the sediment-water interface for P and humic C cycling in the studied stream. Interestingly, we found no interactions between DOM uptake and nitrate or SRP concentrations, or any effect of the added DOM leachates on nitrate uptake, indicating that the increase in DOC concentrations and SRP concentrations were not sufficient to affect the relatively steady nitrate uptake during the experiments. Overall, we show that bulk DOC is a weak predictor of DOC uptake behaviour for complex DOM leachates and that individual DOM compound uptake, nitrate uptake and SRP uptake are controlled very differently within the same aquatic ecosystem. We also found effects of hydromorphology on the uptake of one humic fluorophore and SRP. We conclude that cycling of different C fractions, their interaction and interactions with N and P uptake in streams is a complex, non-linear problem, which can only be assessed with advanced non-linear approaches, such as we present with INSBIRE.

scholarly journals Complex interactions of in-stream dissolved organic matter and nutrient spiralling unravelled by Bayesian regression analysis

2021 ◽  
Vol 18 (10) ◽  
pp. 3103-3122
Author(s):  
Matthias Pucher ◽  
Peter Flödl ◽  
Daniel Graeber ◽  
Klaus Felsenstein ◽  
Thomas Hein ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Transport Processes ◽  
Bayesian Regression ◽  
Positive Interactions ◽  
Cow Dung ◽  
Complex Interactions ◽  
Fluorescence Measurements ◽  
Non Linear ◽  
Nutrient Spiralling

Abstract. Uptake and release patterns of dissolved organic matter (DOM) compounds and co-transported nutrients are entangled, and the current literature does not provide a consistent picture of the interactions between the retention processes of DOM fractions. We performed plateau addition experiments with five different complex DOM leachates in a small experimental stream impacted by diffuse agricultural pollution. The study used a wide range of DOM qualities by including leachates of cow dung, pig dung, corn leaves, leaves from trees, and whole nettle plants. We measured changes in nutrient and dissolved organic carbon (DOC) concentrations along the stream course and determined DOM fractions by fluorescence measurements and parallel factor (PARAFAC) decomposition. To assess the influences of hydrological transport processes, we used a 1D hydrodynamic model. We developed a non-linear Bayesian approach based on the nutrient spiralling concept, which we named the “interactions in nutrient spirals using Bayesian regression” (INSBIRE) approach. This approach can disentangle complex interactions of biotic and abiotic drivers of reactive solutes' uptake in multi-component DOM sources. It can show the variability of the uptake velocities and quantify their uncertainty distributions. Furthermore, previous knowledge of nutrient spiralling can be included in the model using prior probability distributions. We used INSBIRE to assess interactions of compound-specific DOM and nutrient spiralling metrics in our experiment. Bulk DOC uptake varied among sources, showing decreasing uptake velocities in the following order: corn > pig dung > leaves > nettles > cow dung. We found no correlations between bulk DOC uptake and the amounts of protein-like compounds or co-leached soluble reactive phosphorus (SRP). The fastest uptake was observed for SRP and the tryptophan-like component, while the other DOM components' uptake velocities more or less resembled that of the bulk DOC. Almost all DOM components showed a negative relationship between uptake and concentration, known as efficiency loss. Furthermore, we observed a few negative and (weak) positive interactions between the uptake and the concentration of different components, such as a decreased uptake of protein-like compounds at high concentrations of a high-molecular-weight humic-like compound. We also found an influence of the wetted width on the uptake of SRP and a microbially derived humic substance, which indicates the importance of the sediment–water interface for P and humic C cycling in the studied stream. Overall, we show that bulk DOC is a weak predictor of DOC uptake behaviour for complex DOM leachates. Individual DOM compound uptake, including co-leached nutrients, is controlled by both internal (quality-related) and external (environmental) factors within the same aquatic ecosystem. We conclude that the cycling of different C fractions and their mutual interaction with N and P uptake in streams is a complex, non-linear problem, which can only be assessed with advanced non-linear approaches, such as the presented INSBIRE approach.

scholarly journals Corn Grain and Stover Nutrient Uptake Responses from Sandy Soil Treated with Designer Biochars and Compost

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 942
Author(s):  
Jeffrey M. Novak ◽  
Donald W. Watts ◽  
Gilbert C. Sigua ◽  
Thomas F. Ducey
Keyword(s):  
Nutrient Uptake ◽  
Corn Stover ◽  
Pinus Contorta ◽  
Panicum Virgatum ◽  
Zea Mays L ◽  
Sandy Loam ◽  
Nutrient Concentrations ◽  
Extractable P ◽  
Soil Fertility Improvement ◽  
Corn Grain

Biochars are used for soil fertility improvement because they may contain certain elements that plants use as nutrients. However, few studies have demonstrated enhanced crop nutrient uptake. Our study examined nutrient uptake responses of corn (Zea Mays L.) grain and stover over 4 years (Y) after a Goldsboro sandy loam (fine-loamy, siliceous, sub-active, thermic Aquic Paleudults) received different designer biochars and a compost. The designer biochars were produced from lodgepole pine (Pinus contorta) chip (PC), poultry litter (PL), blends with switchgrass (SG; Panicum virgatum), and a SG compost alone. Topsoil treated with 100% PL biochar and blended PC:PL biochar had significantly greater Mehlich 1 (M1) extractable P, K and Na contents compared to the control or other treatments. No significant differences were detected in annual grain nutrient concentrations. In the first corn stover harvest (Y1), significantly greater concentrations of P and K were taken up after treatment with 100% PL biochar, with PC:PL blend and with SG when compared to control. By the fourth corn stover harvest (Y4), nutrient uptake between treatments was not significantly different. Biochar impact on corn stover P, K and Na concentrations was time dependent, suggesting that repeated biochar applications may be needed.

Nutrient cycling differs between cropped soils with century-old and recently pyrolyzed biochar

2021 ◽  
Author(s):  
Victor Burgeon ◽  
Julien Fouché ◽  
Sarah Garré ◽  
Ramin Heidarian-Dehkordi ◽  
Gilles Colinet ◽  
...  
Keyword(s):  
Nutrient Cycling ◽  
Soil Solution ◽  
Nutrient Dynamics ◽  
Chemical Properties ◽  
Crop Productivity ◽  
Nutrient Concentrations ◽  
Soil Productivity ◽  
Long Term Effects ◽  
Mitigation And Adaptation

<p>The amendment of biochar to soils is often considered for its potential as a climate change mitigation and adaptation tool through agriculture. Its presence in tropical agroecosystems has been reported to positively impact soil productivity whilst successfully storing C on the short and long-term. In temperate systems, recent research showed limited to no effect on productivity following recent biochar addition to soils. Its long-term effects on productivity and nutrient cycling have, however, been overlooked yet are essential before the use of biochar can be generalized.</p><p>Our study was set up in a conventionally cropped field, containing relict charcoal kiln sites used as a model for century old biochar (CoBC, ~220 years old). These sites were compared to soils amended with recently pyrolyzed biochar (YBC) and biochar free soils (REF) to study nutrient dynamics in the soil-water-plant system. Our research focused on soil chemical properties, crop nutrient uptake and soil solution nutrient concentrations. Crop plant samples were collected over three consecutive land occupations (chicory, winter wheat and a cover crop) and soil solutions gathered through the use of suctions cups inserted in different horizons of the studied Luvisol throughout the field.</p><p>Our results showed that YBC mainly influenced the soil solution composition whereas CoBC mainly impacted the total and plant available soil nutrient content. In soils with YBC, our results showed lower nitrate and potassium concentrations in subsoil horizons, suggesting a decreased leaching, and higher phosphate concentrations in topsoil horizons. With time and the oxidation of biochar particles, our results reported higher total soil N, available K and Ca in the topsoil horizon when compared to REF, whereas available P was significantly smaller. Although significant changes occurred in terms of plant available nutrient contents and soil solution nutrient concentrations, this did not transcend in variations in crop productivity between soils for neither of the studied crops. Overall, our study highlights that young or aged biochar behave as two distinct products in terms of nutrient cycling in soils. As such the sustainability of these soils differ and their management must therefore evolve with time.</p>

scholarly journals Uptake and translocation of nitrogen, phosphorus and calcium in soybean infected with Meloidogyne incognita and M. javanica

2002 ◽  
Vol 27 (2) ◽  
pp. 141-150 ◽  
Author(s):  
RUI G. CARNEIRO ◽  
PAULO MAZZAFERA ◽  
LUIZ CARLOS C.B. FERRAZ ◽  
TAKASHI MURAOKA ◽  
PAULO CESAR O. TRIVELIN
Keyword(s):  
Nutrient Uptake ◽  
Meloidogyne Incognita ◽  
Nutrient Concentrations ◽  
Tissue Mass ◽  
Split Root ◽  
Split Root System ◽  
Shoot Mass ◽  
Moderately Resistant ◽  
Nitrogen Phosphorus ◽  
Uptake And Transport

Two soybean (Glycine max) cultivars were used in this study, Ocepar 4, rated as moderately resistant to Meloidogyne incognita race 3 but susceptible to M. javanica, and 'BR 16', susceptible to both nematodes. The effect of nematodes infection on the uptake and transport of N, P and Ca to the shoot was studied in plants growing in a split root system. The upper half was inoculated with 0, 3,000, 9,000 or 27,000 eggs/plant while the lower half received 15N, 32P or 45Ca. Infected plants showed an increase of root but a decrease of shoot mass with increasing inoculum levels. In general, total endogenous nutrients increased in the roots and tended to decrease in the shoots with increasing inoculum levels. When concentrations were calculated, there was an increase in the three nutrients in the roots, and an increase of Ca but no significant variation of N and P was observed in the shoots. The total amount of 15N in the roots increased at the highest inoculum levels but 32P and 45Ca decreased. In the shoots there was a reduction of 32P and 45Ca. The specific concentrations of the labelled nutrients (abundance or radioactivity/tissue mass) also showed a decrease of 32P and 45Ca in the shoots and roots of infected plants and an increase of 15N in the shoots. Considering that overall nutrient concentrations reflect cumulative nutrient uptake and the data from labelled elements gave information at a specific moment of the infection, thus nematodes do interfere with nutrient uptake and translocation.

scholarly journals Nitrogen and Phosphorus Uptake Dynamics in Tropical Cerrado Woodland Streams

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1080 ◽  
Author(s):  
Nícolas Reinaldo Finkler ◽  
Flavia Tromboni ◽  
Iola Boëchat ◽  
Björn Gücker ◽  
Davi Gasparini Fernandes Cunha
Keyword(s):  
Nutrient Uptake ◽  
N Uptake ◽  
Pollution Abatement ◽  
Phosphorus Uptake ◽  
Soluble Reactive Phosphorus ◽  
Nitrogen Retention ◽  
Water Velocity ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Lotic Ecosystem

Pollution abatement through phosphorus and nitrogen retention is a key ecosystem service provided by streams. Human activities have been changing in-stream nutrient concentrations, thereby altering lotic ecosystem functioning, especially in developing countries. We estimated nutrient uptake metrics (ambient uptake length, areal uptake rate, and uptake velocity) for nitrate (NO3–N), ammonium (NH4–N), and soluble reactive phosphorus (SRP) in four tropical Cerrado headwater streams during 2017, through whole-stream nutrient addition experiments. According to multiple regression models, ambient SRP concentration was an important explanatory variable of nutrient uptake. Further, best models included ambient NO3–N and water velocity (for NO3–N uptake metrics), dissolved oxygen (DO) and canopy cover (for NH4–N); and DO, discharge, water velocity, and temperature (for SRP). The best kinetic models describing nutrient uptake were efficiency-loss (R2 from 0.47–0.88) and first-order models (R2 from 0.60–0.85). NO3–N, NH4–N, and SRP uptake in these streams seemed coupled as a result of complex interactions of biotic P limitation, abiotic P cycling processes, and the preferential uptake of NH4–N among N-forms. Global change effects on these tropical streams, such as temperature increase and nutrient enrichment due to urban and agricultural expansion, may have adverse and partially unpredictable impacts on whole-stream nutrient processing.

Nutrient distribution in the Bosphorus and surrounding areas

2002 ◽  
Vol 46 (8) ◽  
pp. 59-66 ◽  
Author(s):  
E. Okuş ◽  
A. Aslan-Yilmaz ◽  
A. Yüksek ◽  
S. Taş ◽  
V. Tüfekçi
Keyword(s):  
Chlorophyll A ◽  
Black Sea ◽  
Nutrient Dynamics ◽  
Lower Layer ◽  
Water Quality Monitoring ◽  
Nutrient Concentrations ◽  
The Black Sea ◽  
Sea Of Marmara ◽  
Nutrient Distribution ◽  
Northwestern Shelf

As part of a five years monitoring project “Water Quality Monitoring of the Strait of Istanbul”, February-December 1999 nutrient dynamics of the Black Sea-the Sea of Marmara transect are studied to evaluate the effect of discharges given by deep disposals. Through a one-year study, upper layer nutrient concentrations were generally under the effect of northwestern-shelf Black Sea originated waters. This effect was strictly observed in July, when the upper layer flow was the thickest. On the other hand, partly in November but especially in December the northwestern-shelf Black Sea originated water flow was a minimum resulting in similar concentrations in both layers. Nutrient fluctuations also affected the chlorophyll a and POC concentrations as parameters of productivity. The nutrient concentrations decreased with the effect of spring bloom and highest chlorophyll a values were detected in November at Strait stations that did not match to the Sea of Marmara values. This fact represents the time-scale difference between the Black Sea and the Sea of Marmara. On the contrary, high nutrient concentrations in the lower layer (especially inorganic phosphate), and therefore low N:P ratios reflect the effect of deep discharge. Vertical mixing caused by meteorological conditions of the shallow station (M3) under the effect of surface discharges resulted in homogenous distribution of nutrients. Nutrient concentrations of the stations affected by deep discharge showed that the two-layer stratification of the system did not permit the discharge mix to the upper layer.

scholarly journals Nickel Toxicity Induced Changes in Nutrient Dynamics and Antioxidant Profiling in Two Maize (Zea mays L.) Hybrids

Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 5 ◽  
Author(s):  
Muhammad Amjad ◽  
Hasan Raza ◽  
Behzad Murtaza ◽  
Ghulam Abbas ◽  
Muhammad Imran ◽  
...  
Keyword(s):  
Nutrient Solution ◽  
Elevated Level ◽  
Nutrient Dynamics ◽  
Zea Mays L ◽  
Nutrient Concentrations ◽  
Nickel Toxicity ◽  
Maize Hybrid ◽  
Maize Hybrids ◽  
Growth Physiology ◽  
Induced Changes

Nickel (Ni) is among the essential micronutrient heavy metals utilized by plants. However, an elevated level of Ni causes serious concerns for plants’ physiology and their survival. This study evaluated the mechanisms influencing the growth, physiology, and nutrient dynamics in two commercial maize hybrids (Syngenta and Pioneer) exposed to Ni treatments in hydroponics nutrient solution (NS). Seedlings were raised in plastic trays with quartz sand, and subsequently transferred to Hoagland’s NS at the two leaves stage. After three days of transplantation, Ni levels of 0, 20, and 40 mg L−1 were maintained in the nutrient solution. After 30 days of Ni treatments, seedlings were harvested and different growth, physiological, and nutrient concentrations were determined. The results showed that with increasing Ni concentration, the growth of maize hybrids was significantly reduced, and the maize hybrid, Pioneer, showed significantly higher growth than that of Syngenta at all levels of Ni. Higher growth in Pioneer is ascribed to elevated levels of antioxidant enzymes (SOD, CAT, GR, APX, and POX), lower damage to cellular membranes (i.e., higher MSI and lower MDA), and higher tissue nutrient concentrations (N, P, K, Ca, Mg, Fe, Mn, Zn, and Cu). Furthermore, the maize hybrids showed a difference in nutrient translocation from root to shoot which could be one of the factors responsible for differential response of these hybrids against Ni treatments.

scholarly journals Nutrient Limitation and Uptake Rates in Streams and Rivers of the Greater Yellowstone Ecosystem

2013 ◽  
Vol 36 ◽  
pp. 153-159
Author(s):  
Jennifer Tank ◽  
Alexander Reisinger
Keyword(s):  
Water Quality ◽  
Nutrient Limitation ◽  
Water Column ◽  
Nutrient Dynamics ◽  
Nutrient Retention ◽  
Light Limitation ◽  
Small Stream ◽  
Streams And Rivers ◽  
Greater Yellowstone ◽  
Uptake Studies

Nutrient pollution of aquatic ecosystems is a growing concern as the influence of human activities continues to increase on the landscape. Headwater streams have long been shown to process nutrients via the biofilm community growing on the bottom of streams. The growth and activity of these biofilms is often limited by the availability of nitrogen (N), phosphorus (P), or co-limited by both N and P. Although small stream nutrient dynamics are relatively well understood, comparatively little is known about larger, non-wadeable rivers. Biofilms on the river bottom are likely still nutrient limited, but there becomes an increased potential for light limitation as rivers increase in depth. In addition to biofilms on the bottom of rivers, free-living microbial communities suspended in the water column also occur in rivers and process nutrients - a component of nutrient processing largely ignored in streams. In summer 2013 we worked in streams and rivers of the Greater Yellowstone Area (GYA) to establish the nutrient limitation status of minimally-impacted rivers, as well as the role of the water column in processing nutrients as streams increase in size. For both the nutrient limitation and water column uptake studies, we are using the GYA sites in addition to systems from other regions of the US to establish what controls the various aspects of nutrient dynamics in rivers. Our results from the GYA, in addition to Midwest and Southwest US rivers, will provide water quality managers with new strategies for improving water quality downstream, and clarify mechanisms controlling nutrient retention in rivers.

scholarly journals Design and Fabrication of a Modified Portable Biogas Digester for Renewable Cooking-Gas Production

2018 ◽  
Vol 3 (3) ◽  
pp. 21
Author(s):  
Barinyima Nkoi ◽  
Barinadaa Thaddeus Lebele-Alawa ◽  
Benedict Odobeatu
Keyword(s):  
Pressure Vessel ◽  
Storage Tank ◽  
Raw Materials ◽  
Gas Production ◽  
Smoke Detector ◽  
Cow Dung ◽  
Nickel Steel ◽  
Cylindrical Pressure Vessel ◽  
Test Pressure ◽  
Materials Used

This research paper focuses on re-engineering design and fabrication of a modified potable biogas digester for the production of biogas as a renewable energy source for domestic use. Digesters used around the world are commonly big in size. There is need to modify and re-engineer an existing biogas digester to fit in to modern day design for better efficiency, portability and safety. Floating drum and Flexible balloon are digesters to be modified as a thin walled pressure vessel with radius-thickness ratio  greater than 10. ASME codes and standards were used to carry out the sizing calculations, thickness and pressure calculations for the cylindrical pressure vessel shells and also calculations for the storage tank hemisphere shell. AISI 304 (Chromium-Nickel steel) is used for the vessel shell and the maximum allowable stress is 137 MPa. Weld efficiency (85%), corrosion allowance (0.02mm),  of 24 (for digester),  of 18 (for collector) and  of 20 (storage tank). 17 kg of cow dung and 34 kg of water with temperature of 32oC were the raw materials used for this research to produce a cumulative gas volume of 0.1243 m3 for 30 days. Furthermore, a bike pump is modified and used to increase methane gas pressure from 4.903 kPa to 345 kPa to suit the modern day gas cookers design and storage tank. Unlike other biogas plant, an electronic smoke alarm detector (model: Ei100) is placed 300 mm below the digester top for effective fire protection. Series of tests were performed to ensure that the constructed prototype met the specifications/standards. Such test include, smoke detector test, pressure testing, gas leak test, and a unit test run also confirmed that the aim of research was achieved.

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