Inorganic Nitrogen Production and Removal along the Sediment Gradient of a Stormwater Infiltration Basin

Stormwater infiltration basins (SIBs) are vegetated depressions that collect stormwater and allow it to infiltrate to underlying groundwater. Their pollutant removal efficiency is affected by the properties of the soils in which they are constructed. We assessed the soil nitrogen (N) cycle processes that produce and remove inorganic N in two urban SIBs, with the goal of further understanding the mechanisms that control N removal efficiency. We measured net N mineralization, nitrification, and potential denitrification in wet and dry seasons along a sedimentation gradient in two SIBs in the subtropical Tampa, Florida urban area. Net N mineralization was higher in the wet season than in the dry season; however, nitrification was higher in the dry season, providing a pool of highly mobile nitrate that would be susceptible to leaching during periodic dry season storms or with the onset of the following wet season. Denitrification decreased along the sediment gradient from the runoff inlet zone (up to 5.2 μg N/g h) to the outermost zone (up to 3.5 μg N/g h), providing significant spatial variation in inorganic N removal for the SIBs. Sediment accumulating around the inflow areas likely provided a carbon source, as well as maintained stable anaerobic conditions, which would enhance N removal.

Download Full-text

Modelling of seasonal effects of soil processes on N leaching in northern latitudes

Hydrology Research ◽

10.2166/nh.2004.0026 ◽

2004 ◽

Vol 35 (4-5) ◽

pp. 347-357 ◽

Cited By ~ 4

Author(s):

K. Rankinen ◽

K. Granlund ◽

I. Bärlund

Keyword(s):

Land Use ◽

N Mineralization ◽

Inorganic Nitrogen ◽

Mineral Soil ◽

Seasonal Effects ◽

N Leaching ◽

Net N Mineralization ◽

Inorganic N ◽

Northern Latitudes ◽

Dormant Season

Concentrations of inorganic nitrogen (N) in non-polluted and undisturbed northern rivers are often lower during summer than during the dormant season. The great difference between summer and winter N concentrations probably reflects higher soil water N contents in the dormant season compared with the growing season, when inorganic N is usually retained effectively. Microbial activity in soil is observed even in sub-zero temperatures and it is generally assumed that in the northern latitudes some N mineralization occurs during winter. The dynamic, semi-distributed INCA (Integrated Nitrogen in Catchments) model was applied to the Simojoki river basin in the boreal zone in northern Finland. With this model process rates and loads of N can be simulated in different land use modes. The INCA model was not able to simulate the high inorganic N concentrations in the river water in winter unless N processes in sub-zero temperatures were included. The aim of this study was to compare the simulated N mineralization in two different land use modes: boreal forests on mineral soil and agricultural fields. Net N mineralization occurring during the season when soil is mainly frozen (November–April) accounted for 43% of the annual N mineralization. This work indicates the importance of over-winter N processes in northern areas, which should be taken into account when modelling nutrient leaching.

Download Full-text

Soil nitrogen transformation responses to seasonal precipitation changes are regulated by changes in functional microbial abundance in a subtropical forest

10.5194/bg-2017-3 ◽

2017 ◽

Author(s):

Jie Chen ◽

Guoliang Xiao ◽

Yakov Kuzyakov ◽

Darrel Jenerette ◽

Ying Ma ◽

...

Keyword(s):

N Mineralization ◽

N2o Emission ◽

Dry Season ◽

Subtropical Forest ◽

Net N Mineralization ◽

Microbial Abundance ◽

Wet Season ◽

Net Nitrification ◽

N Transformation ◽

Precipitation Changes

Abstract. More dry-season droughts and wet-season storms have been predicted in subtropical areas. Since subtropical forest soils are significant sources of N2O and NO3−, it is important to understand the features and determinants of N transformation responses to the predicted precipitation changes. A precipitation manipulation field experiment was conducted to reduce dry-season precipitation and increase wet-season precipitation, while keeping the annual precipitation unchanged in a subtropical forest. Net N mineralization, net nitrification, N2O emission, nitrifying (bacterial and archaeal amoA) and denitrifying (nirK, nirS and nosZ) genes abundance, microbial biomass carbon (MBC) and soil physicochemical properties were monitored to characterize and explain soil N transformation responses. Dry-season precipitation reduction decreased net nitrification and N mineralization rates by 13–20 %, while wet-season precipitation addition increased both rates by 50 %. More than 20 % of the total variation of net nitrification and N mineralization could be explained by microbial abundance and soil water content (SWC), but archaeal amoA abundance was the main factor. Increased net nitrification in wet season together with large precipitation events caused substantial NO3− losses via leaching. However, N2O emission decreased moderately either in dry or wet seasons due to changes in nosZ gene abundance, MBC, net nitrification and SWC (decreased by 10–21 %). We conclude that reducing dry-season precipitation and increasing wet-season precipitation affect N transformation mainly through altering functional microbial abundance and MBC, which are further determined by changes in DOC and NH4+ availabilities. Such contrasting precipitation pattern will increase droughts and NO3− leaching in subtropical forests.

Download Full-text

Nitrogen Availability in Biochar-Amended Soils with Excessive Compost Application

Agronomy ◽

10.3390/agronomy10030444 ◽

2020 ◽

Vol 10 (3) ◽

pp. 444 ◽

Cited By ~ 3

Author(s):

Chen-Chi Tsai ◽

Yu-Fang Chang

Keyword(s):

N Mineralization ◽

Nitrogen Availability ◽

Agricultural Soils ◽

Inorganic Nitrogen ◽

Clay Content ◽

N Availability ◽

Net N Mineralization ◽

Mineral N ◽

Mineralization Potential ◽

The Impact

Adding biochar to excessive compost amendments may affect compost mineralization rate and nitrogen (N) availability. The objective of this 371-day incubation study was to evaluate the effects of four proportions of woody biochar (0%, 0.5%, 1.0%, and 2.0%) from lead tree (Leucaena leucocephala (Lam.) de. Wit) biochar produced at 750 °C through dynamic mineral N and N mineralization rates in three rural soils (one Oxisol and two Inceptisols). In each treatment, 5% poultry–livestock manure compost was added to serve as an excessive application. The results indicated that the biochar decreased available total inorganic nitrogen (TIN) (NO3−-N+NH4+-N) by on average 6%, 9% and 19% for 0.5%, 1.0% and 2.0% treatments, respectively. The soil type strongly influenced the impact of the biochar addition on the soil nitrogen mineralization potential, especially the soil pH and clay content. This study showed that the co-application of biochar and excessive compost benefited the agricultural soils by improving NO3−-N retention in agroecosystems. The application of biochar to these soils to combine it with excessive compost appeared to be an effective method of utilizing these soil amendments, as it diminished the net N mineralization potential and reduced the nitrate loss of the excessive added compost.

Download Full-text

The simulated N deposition accelerates net N mineralization and nitrification in a tropical forest soil

Biogeosciences ◽

10.5194/bg-16-4277-2019 ◽

2019 ◽

Vol 16 (21) ◽

pp. 4277-4291

Author(s):

Yanxia Nie ◽

Xiaoge Han ◽

Jie Chen ◽

Mengcen Wang ◽

Weijun Shen

Keyword(s):

N Deposition ◽

Functional Genes ◽

Net N Mineralization ◽

Soil N ◽

Wet Season ◽

Inorganic N ◽

N Transformations ◽

N Transformation ◽

Soil N Transformation ◽

N Additions

Abstract. Elevated nitrogen (N) deposition affects soil N transformations in the N-rich soil of tropical forests. However, the change in soil functional microorganisms responsible for soil N cycling remains largely unknown. Here, we investigated the variation in soil inorganic N content, net N mineralization (Rm), net nitrification (Rn), inorganic N leaching (Rl), N2O efflux and N-related functional gene abundance in a tropical forest soil over a 2-year period with four levels of N addition. The responses of soil net N transformations (in situ Rm and Rn) and Rl to N additions were negligible during the first year of N inputs. The Rm, Rn, and Rl increased with the medium nitrogen (MN) and high nitrogen (HN) treatments relative to the control treatments in the second year of N additions. Furthermore, the Rm, Rn, and Rl were higher in the wet season than in the dry season. The Rm and Rn were mainly associated with the N addition-induced lower C:N ratio in the dry season but with higher microbial biomass in the wet season. Throughout the study period, high N additions increased the annual N2O emissions by 78 %. Overall, N additions significantly facilitated Rm, Rn, Rl and N2O emission. In addition, the MN and HN treatments increased the ammonia-oxidizing archaea (AOA) abundance by 17.3 % and 7.5 %, respectively. Meanwhile, the HN addition significantly increased the abundance of nirK denitrifiers but significantly decreased the abundance of ammonia-oxidizing bacteria (AOB) and nosZ-containing N2O reducers. To some extent, the variation in functional gene abundance was related to the corresponding N-transformation processes. Partial least squares path modelling (PLS-PM) indicated that inorganic N contents had significantly negative direct effects on the abundances of N-related functional genes in the wet season, implying that chronic N deposition would have a negative effect on the N-cycling-related microbes and the function of N transformation. Our results provide evidence that elevated N deposition may impose consistent stimulatory effects on soil N-transformation rates but differentiated impacts on related microbial functional genes. Long-term experimentation or observations are needed to decipher the interrelations between the rate of soil N-transformation processes and the abundance or expression of related functional genes.

Download Full-text

Variation with slope aspect in effects of temperature on nitrogen mineralization and nitrification in mineral soil of mixed hardwood forests

Canadian Journal of Forest Research ◽

10.1139/cjfr-2015-0087 ◽

2015 ◽

Vol 45 (7) ◽

pp. 958-962 ◽

Cited By ~ 10

Author(s):

Frank S. Gilliam ◽

Julia E. Galloway ◽

Jacob S. Sarmiento

Keyword(s):

N Mineralization ◽

Incubation Temperature ◽

Global Climate ◽

Mineral Soil ◽

Slope Aspect ◽

Net N Mineralization ◽

Inorganic N ◽

N Dynamics ◽

Net Nitrification ◽

Effects Of Temperature

This study examined the effects of temperature on soil nitrogen (N) dynamics and variation with slope aspect (northeast (NE) versus southwest (SW)) at two forested sites in West Virginia — Beech Fork Lake (BFL) and Fernow Experimental Forest (FEF) — with similar soil and overstory characteristics but with different latitudes and elevations. Previous work on mineral soil from both sites had shown sharp differences in microbial communities between SW slopes and NE slopes. Mineral soil was sampled from three and eight plots per aspect at FEF and BFL, respectively. Inorganic N was extracted from samples, which were then divided into polyethylene bags for 7-day incubations at 4 °C, 15 °C, 25 °C, and 35 °C. Following incubation, soils were extracted and analyzed for inorganic N. Net N mineralization varied significantly between aspects and temperatures but did not vary between sites; net nitrification varied significantly between aspects, temperatures, and sites. Net N mineralization increased with incubation temperature at all aspects and sites. Net nitrification rates increased with incubation temperature for BFL soils; however, maximum net nitrification rates occurred at 20–25 °C for FEF soils. Net nitrification was essentially undetectable for SW soils at either site. Results underline the complexities of the N cycle in temperate forest ecosystems, representing challenges in predicting alterations in soil N dynamics under conditions of global climate change.

Download Full-text

Effects of snow absence on N pools and enzyme activities within soil aggregates in a spruce forest on the eastern Tibetan Plateau

10.21203/rs.3.rs-226750/v1 ◽

2021 ◽

Author(s):

Zhijie Li ◽

Zimin Li ◽

Rüdiger Reichel ◽

Kaijun Yang ◽

Li Zhang ◽

...

Keyword(s):

Tibetan Plateau ◽

Snow Cover ◽

Enzyme Activities ◽

N Mineralization ◽

Soil Aggregates ◽

Net N Mineralization ◽

Spruce Forest ◽

Soil N ◽

Eastern Tibetan Plateau ◽

Inorganic N

Abstract Background Snow cover change has a great potential to impact soil nitrogen (N) pools and enzyme activities in boreal forests. Yet, the nature of this biochemical processes within soil aggregates is still limited. We conducted a snow manipulation experiment to investigate the effects of snow absence on N pools and enzyme activities within soil aggregates in a subalpine spruce forest on the eastern Tibetan Plateau of China. Results Snow absence increased extractable inorganic N pools (ammonium and nitrate) and enzyme activities, accompanying with the improvement of N mineralization rate. Regardless of snow manipulations, both soil extractable inorganic N and net N mineralization was higher in macroaggregates than that in the other two aggregates. In contrast, microaggregates had higher urease and nitrite reductase activities compared to macroaggregates and large macroaggregates. Compared with small macroaggregates and large macroaggregates, N pools and enzymes within microaggregates is more sensitive to snow absence. Conclusions Our results indicated that the impacts of snow cover change on soil N dynamic depend on aggregate sizes and winter conditions (e.g., snow cover and temperature). Such findings have important implication for soil N cycling in snow-covered subalpine forests experiencing pronounced winter climate change.

Download Full-text

Dissolved inorganic nitrogen in a tropical estuary in Malaysia: transport and transformation

Biogeosciences ◽

10.5194/bg-16-2821-2019 ◽

2019 ◽

Vol 16 (14) ◽

pp. 2821-2836 ◽

Cited By ~ 11

Author(s):

Shan Jiang ◽

Moritz Müller ◽

Jie Jin ◽

Ying Wu ◽

Kun Zhu ◽

...

Keyword(s):

Primary Productivity ◽

Inorganic Nitrogen ◽

River Estuary ◽

Dry Season ◽

Similar Distribution ◽

Tropical Estuary ◽

Dissolved Inorganic Nitrogen ◽

Wet Season ◽

Terrestrial Organic Matter ◽

Transport And Transformation

Abstract. Dissolved inorganic nitrogen (DIN), including nitrate, nitrite and ammonium, frequently acts as the limitation for primary productivity. Our study focused on the transport and transformation of DIN in a tropical estuary, i.e., the Rajang River estuary, in Borneo, Malaysia. Three cruises were conducted in August 2016 and February–March and September 2017, covering both dry and wet seasons. Before entering the coastal delta, decomposition of the terrestrial organic matter and the subsequent soil leaching was assumed to be the main source of DIN in the river water. In the estuary, decomposition of dissolved organic nitrogen was an additional DIN source, which markedly increased DIN concentrations in August 2016 (dry season). In the wet season (February 2017), ammonium concentrations showed a relatively conservative distribution during the mixing, and the nitrate addition was weak. La Niña events induced high precipitations and discharge rates, decreased reaction intensities of ammonification and nitrification. Hence similar distribution patterns of DIN species in the estuary were found in September 2017 (end of the dry season). The magnitude of riverine DIN flux varied between 77.2 and 101.5 t N d−1, which might be an important support for the coastal primary productivity.

Download Full-text

A comparative account of the microbial biomass-N and N-mineralization of soils under natural forest, grassland and crop field from dry tropical region, India

Plant Soil and Environment ◽

10.17221/1021-pse ◽

2009 ◽

Vol 55 (No. 6) ◽

pp. 223-230 ◽

Cited By ~ 14

Author(s):

S. Singh Jay ◽

D.P. Singh ◽

A.K. Kashyap

Keyword(s):

Soil Moisture ◽

Microbial Biomass ◽

N Mineralization ◽

Mixed Forest ◽

Microbial Biomass N ◽

Tropical Region ◽

Net N Mineralization ◽

Inorganic N ◽

Total N ◽

Biomass N

This study investigated microbial biomass-N (MB-N) and N-mineralization in soils of four different vegetation systems including forest (sal), mixed forest, savanna and cropland ecosystems in the Vindhyan region, India. A change was noted in the above region due to physiographic differences and anthropogenic disturbances. Annually the soil moisture (SM) content across the different study sites ranged from 7.5 to 24.3% being maximum in forest sites compared to savanna and cropland sites. The NH4+-N, NO -3 -N and MB-N concentrations varied from 4.3 to 10.2 μg/g, 1.1 to 5.8 μg/g and 21.3 to 90.2 μg/g dry soil, respectively, with minimum values in the wet and maximum values in the dry season. The trend of seasonal variation in net N-mineralization was similar to that of moisture content but counter to the concentrations of inorganic-N and MB-N. The net N-mineralization rates at different investigated sites ranged from 4.5 to 37.6 μg/g month. Cultivation reduced the N-mineralization and MB-N by 58.5% and 63.5%, respectively. Experiments showed that the percentage contribution of MB-N to total-N was 8.01 to 19.15%. MB-N was positively correlated with the inorganic-N (n = 180,r.80,P < 0.001) but negatively with soil moisture (n = 180, r = 0.79, P < 0.001) and net N-mineralization rates (n = 180, r = 0.92, P < 0.0001). The higher N-mineralization and MB-N in the soil of forest ecosystem was reported compared to savanna and cropland and the order of soil MB-N levels and net N-mineralization followed the sequence: forest (sal) > mixed forest > savanna > cropland.

Download Full-text

Treatment of laboratory wastewater in a tropical constructed wetland comparing surface and subsurface flow

Water Science & Technology ◽

10.2166/wst.2001.0872 ◽

2001 ◽

Vol 44 (11-12) ◽

pp. 499-506 ◽

Cited By ~ 14

Author(s):

A.A. Meutia

Keyword(s):

Removal Efficiency ◽

Constructed Wetland ◽

Rainy Season ◽

Transition Period ◽

Subsurface Flow ◽

Dry Season ◽

Surface Flow ◽

Cod Removal ◽

N Removal ◽

Removal Efficiencies

Wastewater treatment by constructed wetland is an appropriate technology for tropical developing countries like Indonesia because it is inexpensive, easily maintained, and has environmentally friendly and sustainable characteristics. The aim of the research is to examine the capability of constructed wetlands for treating laboratory wastewater at our Center, to investigate the suitable flow for treatment, namely vertical subsurface or horizontal surface flow, and to study the effect of the seasons. The constructed wetland is composed of three chambered unplanted sedimentation tanks followed by the first and second beds, containing gravel and sand, planted with Typha sp.; the third bed planted with floating plant Lemna sp.; and a clarifier with two chambers. The results showed that the subsurface flow in the dry season removed 95% organic carbon (COD) and total phosphorus (T-P) respectively, and 82% total nitrogen (T-N). In the transition period from the dry season to the rainy season, COD removal efficiency decreased to 73%, T-N increased to 89%, and T-P was almost the same as that in the dry season. In the rainy season COD and T-N removal efficiencies increased again to 95% respectively, while T-P remained unchanged. In the dry season, COD and T-P concentrations in the surface flow showed that the removal efficiencies were a bit lower than those in the subsurface flow. Moreover, T-N removal efficiency was only half as much as that in the subsurface flow. However, in the transition period, COD removal efficiency decreased to 29%, while T-N increased to 74% and T-P was still constant, around 93%. In the rainy season, COD and T-N removal efficiencies increased again to almost 95%. On the other hand, T-P decreased to 76%. The results show that the constructed wetland is capable of treating the laboratory wastewater. The subsurface flow is more suitable for treatment than the surface flow, and the seasonal changes have effects on the removal efficiency.

Download Full-text

Comparison of Wastewater Treatment Technologies in the ED-WAVE Tool to Technologies of Similar Cases in Malawi: Case of Blantyre and Soche WWTW

The Open Civil Engineering Journal ◽

10.2174/18741495010040100057 ◽

2010 ◽

Vol 4 (1) ◽

pp. 57-64

Author(s):

Victor Chipofya ◽

Andrzej Kraslawski ◽

Yury Avramenko

Keyword(s):

Wastewater Treatment ◽

Removal Efficiency ◽

Biological Treatment ◽

Dry Season ◽

Wet Season ◽

Trickling Filters ◽

Treatment Technologies ◽

The Difference ◽

Study Manager

This paper compares the wastewater treatment technologies at Blantyre and Soche wastewater treatment works (WWTW) in Malawi with technologies of a similar case according to the ED-WAVE tool to determine if existing cases in the tool can be invoked and appropriately modified to arrive at a particular design alternative. The ED-WAVE tool is a shareware PC based package for imparting training on wastewater treatment technologies. The system consists of four modules viz. Reference Library, Process Builder, Case Study Manager, and Treatment Adviser. The paper also compares the reduction in the levels of BOD5, COD, and TSS at the three respective treatment works. The study established that there is a similarity in the sequencing of treatment units of Municipal Case 6 in the ED-WAVE tool and the sequencing of treatment units at Blantyre and Soche WWTW, respectively. All the three plants incorporate screening, grit removal, aerobic biological treatment, and sedimentation. Soche and Blantyre WWTW use hand-raked inclined bar screens and constant velocity grit channels, where longitudinal flow velocity is hydraulically controlled. Rotary mechanically-raked bar screens and mechanically stirred grit chambers are used in the ED-WAVE tool. In addition, Municipal Case 6 uses oxidation ditches for aerobic biological treatment while Blantyre and Soche WWTW use trickling filters. BOD5 removal efficiency at Soche WWTW at 95% and 96% for dry season and wet season, respectively, is comparable to the removal efficiency at Municipal Case 6 (95%). The dry season BOD5 removal efficiency at Blantyre WWTW at 87% is slightly lower than the removal efficiency at Municipal Case 6. TSS removal efficiency at Soche WWTW is at 80% in the wet season and 35% in the dry season. TSS removal efficiency at Blantyre WWTW is only 3% in the wet season, while there is an increase of 11% in the wet season. TSS removal efficiency at Municipal Case 6 is 96%. Inspite of the difference in the BOD5 and TSS removal efficiencies at Municipal Case 6 as compared to Blantyre and Soche WWTW, there is a close match in technologies at Blantyre and Soche WWTW, and Municipal Case 6 in Greece as invoked by the Case Study Manager in the ED- WAVE tool. What is evident from this study is the need to appropriately modify the case arrived at through the Case Study Manager in order to come up with a design appropriate to the local situation in terms of operation and maintenance.

Download Full-text