Effects of Hydrological Processes on Surface and Subsurface Nitrogen Losses from Purple Soil Slopes

2021 ◽  
Author(s):  
Meixiang Xie ◽  
Pingcang Zhang ◽  
Yuanzhi Shi ◽  
Dalin Hong
Keyword(s):  
Ammonia Nitrogen ◽  
Surface Flow ◽  
Hydrological Processes ◽  
Purple Soil ◽  
Slope Gradient ◽  
N Loss ◽  
N Losses ◽  
Critical Slope ◽  
Study Laboratory ◽  
Critical Slope Gradient

Abstract Relationships of hydrological processes via surface flow (SF) and subsurface flow (SSF) to nitrogen (N) losses from sloping farmlands have been rarely researched. In this study, laboratory experiments were conducted to investigate ammonia nitrogen (NH4-N), nitrate nitrogen (NO3-N) and total nitrogen (TN) losses from purple sloped soils due to SF, SSF and sediment (S). Effects of rainfalls and slope gradients on N losses were also studied. Three rainfall intensities (0.4 ± 0.02, 1.0 ± 0.04 and 1.8 ± 0.11 mm min-1) and four slope gradients (5°, 10°, 15° and 20°) were designed in experiments. Larger SF discharges occurred with increasing rainfall intensities while SSF was prone to happen under low rainfall intensities. Although r2 of regression results were low, both N loss concentrations and loads coincided positively with discharges except for a negative relation between N concentrations and SF discharges. In comparison, smaller SSF discharges produced substantial N loads with higher N concentrations especially for NO3-N. NH4-N, NO3-N, and TN losses were dominated by S, SSF and SF, respectively. Furthermore, linear increases in loss loads with increasing discharges revealed that distributions of N loss loads were compatible with flow distributions in stormwater. 10° may be a critical slope gradient for SSF discharge and nutrient export.

scholarly journals The interaction of seasonal rainfall and nitrogen fertiliser rate on soil N2O emission, total N loss and crop yield of dryland sorghum and sunflower grown on sub-tropical Vertosols

Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 604 ◽  
Author(s):  
G. D. Schwenke ◽  
B. M. Haigh
Keyword(s):  
Crop Yield ◽  
Crop Production ◽  
Field Experiments ◽  
N2o Emission ◽  
N2o Emissions ◽  
N Loss ◽  
N Losses ◽  
Total N ◽  
Tropical Regions ◽  
The Impact

Summer crop production on slow-draining Vertosols in a sub-tropical climate has the potential for large emissions of soil nitrous oxide (N2O) from denitrification of applied nitrogen (N) fertiliser. While it is well established that applying N fertiliser will increase N2O emissions above background levels, previous research in temperate climates has shown that increasing N fertiliser rates can increase N2O emissions linearly, exponentially or not at all. Little such data exists for summer cropping in sub-tropical regions. In four field experiments at two locations across two summers, we assessed the impact of increasing N fertiliser rate on both soil N2O emissions and crop yield of grain sorghum (Sorghum bicolor L.) or sunflower (Helianthus annuus L.) in Vertosols of sub-tropical Australia. Rates of N fertiliser, applied as urea at sowing, included a nil application, an optimum N rate and a double-optimum rate. Daily N2O fluxes ranged from –3.8 to 2734g N2O-Nha–1day–1 and cumulative N2O emissions ranged from 96 to 6659g N2O-Nha–1 during crop growth. Emissions of N2O increased with increased N fertiliser rates at all experimental sites, but the rate of N loss was five times greater in wetter-than-average seasons than in drier conditions. For two of the four experiments, periods of intense rainfall resulted in N2O emission factors (EF, percent of applied N emitted) in the range of 1.2–3.2%. In contrast, the EFs for the two drier experiments were 0.41–0.56% with no effect of N fertiliser rate. Additional 15N mini-plots aimed to determine whether N fertiliser rate affected total N lost from the soil–plant system between sowing and harvest. Total 15N unaccounted was in the range of 28–45% of applied N and was presumed to be emitted as N2O+N2. At the drier site, the ratio of N2 (estimated by difference)to N2O (measured) lost was a constant 43%, whereas the ratio declined from 29% to 12% with increased N fertiliser rate for the wetter experiment. Choosing an N fertiliser rate aimed at optimum crop production mitigates potentially high environmental (N2O) and agronomic (N2+N2O) gaseous N losses from over-application, particularly in seasons with high intensity rainfall occurring soon after fertiliser application.

Characteristics of Non-Point Source N Export via Surface Runoff from Sloping Croplands in Northeast China

2011 ◽  
Vol 347-353 ◽  
pp. 2302-2307 ◽  
Author(s):  
Hong Xiang Wang ◽  
Yi Shi ◽  
Jian Ma ◽  
Cai Yan Lu ◽  
Xin Chen
Keyword(s):  
Point Source ◽  
Surface Runoff ◽  
Rainfall Intensity ◽  
Inorganic Nitrogen ◽  
Rainfall Amount ◽  
Organic N ◽  
Dissolved Inorganic Nitrogen ◽  
Slope Gradient ◽  
N Loss ◽  
Total N

A field experiment was conducted to study the characteristics of non-point source nitrogen (N) in the surface runoff from sloping croplands and the influences of rainfall and cropland slope gradient. The results showed that dissolved total N (DTN) was the major form of N in the runoff, and the proportion occupied by dissolved inorganic nitrogen (DIN) ranged from 45% to 85%. The level of NH4+-N was generally higher than the level of NO3--N, and averaged at 2.50 mg·L-1and 1.07 mg·L-1respectively. DIN was positively correlated with DTN (R2=0.962). Dissolved organic N (DON) presented a moderate seasonal change and averaged at 1.40 mg·L-1. Rainfall amount and rainfall intensity significantly affected the components of DTN in the runoff. With the increase of rainfall amount and rainfall intensity, the concentrations of DTN, NH4+-N and NO3--N presented a decreased trend, while the concentration of DON showed an increased trend. N loss went up with an increase in the gradient of sloping cropland, and was less when the duration was longer from the time of N fertilization.fertilization.

scholarly journals Extent and Variation of Nitrogen Losses from Non-legume Field Crops of Conterminous United States

Nitrogen ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 34-51
Author(s):  
Amitava Chatterjee
Keyword(s):  
United States ◽  
Management Strategies ◽  
Application Rate ◽  
Fertilizer N ◽  
N Loss ◽  
N Losses ◽  
Field Crops ◽  
N Application Rate ◽  
Spatio Temporal ◽  
N Management

Nitrogen (N) losses from field crops have raised environmental concerns. This manuscript accompanies a database of N loss studies from non-legume field crops conducted across the conterminous United States. Cumulative N losses through nitrous oxide-denitrification (CN2O), ammonia volatilization (CNH3), and nitrate leaching (CNO3−) during the growing season and associated crop, soil, and water management information were gathered to determine the extent and controls of these losses. This database consisted of 404, 26, and 358 observations of CN2O, CNH3, and CNO3− losses, respectively, from sixty-two peer-reviewed manuscripts. Corn (Zea mays) dominated the N loss studies. Losses ranged between −0.04 to 16.9, 2.50 to 50.9, and 0 to 257 kg N ha−1 for CN2O, CNH3 and CNO3−, respectively. Most CN2O and CNO3− observations were reported from Colorado (n = 100) and Iowa (n = 176), respectively. The highest values of CN2O, and CNO3− were reported from Illinois and Minnesota states, and corn and potato (Solanum tuberosum), respectively. The application of anhydrous NH3 had the highest value of CN2O loss, and ammonium nitrate had the highest CNO3− loss. Among the different placement methods, the injection of fertilizer-N had the highest CN2O loss, whereas the banding of fertilizer-N had the highest CNO3− loss. The maximum CNO3− loss was higher for chisel than no-tillage practice. Both CN2O and CNO3− were positively correlated with fertilizer N application rate and the amount of water input (irrigation and rainfall). Fertilizer-N management strategies to control N loss should consider the spatio-temporal variability of interactions among climate, crop-and soil types.

scholarly journals Assessment of TMPA 3B42V7 and PERSIANN-CDR in Driving Hydrological Modeling in a Semi-Humid Watershed in Northeastern China

2020 ◽  
Vol 12 (19) ◽  
pp. 3133
Author(s):  
Lu Zhang ◽  
Zhuohang Xin ◽  
Huicheng Zhou
Keyword(s):  
Hydrological Modeling ◽  
Assessment Tool ◽  
Surface Flow ◽  
Northeastern China ◽  
Base Flow ◽  
Hydrological Processes ◽  
Superior Performance ◽  
Climate Data ◽  
Satellite Precipitation ◽  
Precipitation Estimation

Recent developments of satellite precipitation products provide an unprecedented opportunity for better precipitation estimation, and thus broaden hydrological application. However, due to the errors and uncertainties of satellite products, a thorough validation is usually required before putting into the real hydrological application. As such, this study aims to provide a comprehensive evaluation on the performances of Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis (TMPA) 3B42V7 and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR), as well as their adequacies in simulating hydrological processes in a semi-humid region in the northeastern China. It was found that TMPA 3B42V7 showed a superior performance at the daily and monthly time scales, and had a favorable capture of the rainfall-intensity distribution. Intra-annual comparisons indicated a better representation of TMPA 3B42V7 from January to September, whereas PERSIANN-CDR was more reliable from October to December. The Soil and Water Assessment Tool (SWAT) driven by gauge precipitation data performed excellently with NSE > 0.9, while the performances of TMPA 3B42V7- and PERSIANN-CDR-based models are satisfactory with NSE > 0.5. The performances varied under different flow levels and hydrological years. Water balance analysis indicated a better performance of TMPA 3B42V7 in simulating the hydrological processes, including evapotranspiration, groundwater recharge and total runoff. The runoff compositions (i.e., base flow, subsurface flow, and surface flow) driven by TMPA 3B42V7 were more accordant with the actual hydrological features. This study will not only help recognize the potential satellite precipitation products for local water resources management, but also be a reference for the poor-gauged regions with similar hydrologic and climatic conditions around the world, especially the northeastern China and western Russia.

scholarly journals Hydraulic characteristics and sediment generation on slope erosion in the Three Gorges Reservoir Area, China

2016 ◽  
Vol 64 (3) ◽  
pp. 237-245 ◽  
Author(s):  
Feng Qian ◽  
Dongbin Cheng ◽  
Wenfeng Ding ◽  
Jiesheng Huang ◽  
Jingjun Liu
Keyword(s):  
Soil Erosion ◽  
Sediment Yield ◽  
Rainfall Intensity ◽  
Purple Soil ◽  
Three Gorges ◽  
Slope Gradient ◽  
Stream Power ◽  
Yield Rate ◽  
The Three Gorges ◽  
Subsurface Runoff

Abstract Hydrological processes play important roles in soil erosion processes of the hillslopes. This study was conducted to investigate the hydrological processes and the associated erosional responses on the purple soil slope. Based on a comprehensive survey of the Wangjiaqiao watershed in the Three Gorges Reservoir, four typical slope gradients (5°, 10°, 15°and 20°) were applied to five rainfall intensities (0.6, 1.1, 1.61, 2.12 and 2.54 mm·min-1). The results showed that both surface and subsurface runoff varied greatly depending on the rainfall intensity and slope gradient. Surface runoff volume was 48.1 to 280.1 times of that for subsurface runoff. The critical slope gradient was about 10°. The sediment yield rate increased with increases in both rainfall intensity and slope gradient, while the effect of rainfall intensity on the sediment yield rate was greater than slope gradient. There was a good linear relationship between sediment yield rate and Reynolds numbers, flow velocity and stream power, while Froude numbers, Darcy-Weisbach and Manning friction coefficients were not good hydraulic indicators of the sediment yield rate of purple soil erosion. Among the three good indicators (Re, v and w), stream power was the best predictor of sediment yield rate (R2 = 0.884). Finally, based on the power regression relationship between sediment yield rate, runoff rate, slope gradient and rainfall intensity, an erosion model was proposed to predict the purple soil erosion (R2 = 0.897). The results can help us to understand the relationship between flow hydraulics and sediment generation of slope erosion and offer useful data for the building of erosion model in purple soil.

Tech-IA floating system introduced in urban wastewater treatment plants in the Veneto region – Italy

2013 ◽  
Vol 68 (5) ◽  
pp. 1144-1150 ◽  
Author(s):  
Anna Mietto ◽  
Maurizio Borin ◽  
Michela Salvato ◽  
Paolo Ronco ◽  
Nicola Tadiello
Keyword(s):  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Alnus Glutinosa ◽  
Primary Treatment ◽  
Ammonia Nitrogen ◽  
Surface Flow ◽  
Treatment Wetland ◽  
N Removal ◽  
Floating System

The performance of three integrated wetland treatment plants (horizontal sub-surface flow (h-SSF) and floating treatment wetland (FTW) with differentiated primary treatments) designed for treating domestic wastewater was investigated, monitoring total (TN), nitrate (NO3-N), nitrite (NO2-N) and ammonia nitrogen (NH4-N), total (TP) and phosphate phosphorus (PO4-P), chemical (COD) and biological oxygen demand (BOD5), and dissolved oxygen (DO) at the inlet and outlet of each wetland section from February 2011 to June 2012. Sediments settled in the FTW were collected and analyzed. The growth of plants in each system was also monitored, observing their general conditions. The chemical–physical characteristics of the pretreated domestic wastewater depended on the primary treatment installed. During the monitoring period we observed different reduction performance of the wetland sector in the three sites. In general, the wetland systems demonstrated the capacity to reduce TN, COD, BOD5 and Escherichia coli, whereas NO3-N and NH4-N removal was strictly influenced by the chemical conditions, in particular DO concentration, in the h-SSF and FTW. Vegetation (Phragmites australis, Alnus glutinosa and Salix eleagnos) was well established in the h-SSF as well as in the floating elements (Iris pseudacorus), although there were some signs of predation. FTW is a relatively novel wetland system, so the results obtained from this study can pave the way for the application of this technology.

Recovery of 15N-labelled fertilizers applied to barley on two artificially eroded soils in north-central Alberta

1998 ◽  
Vol 78 (2) ◽  
pp. 377-383 ◽  
Author(s):  
R. Pradhan ◽  
R. C. Izaurralde ◽  
S. S. Malhi ◽  
M. Nyborg
Keyword(s):  
Field Experiments ◽  
Water Saturation ◽  
Nutrient Use Efficiency ◽  
N Loss ◽  
Hordeum Vulgare L ◽  
N Losses ◽  
North Central ◽  
Major Mechanism ◽  
Erosion Level ◽  
N Management

Soil erosion induces variability in soil properties which may influence nutrient use efficiency. A 2-yr field study was conducted with the following objectives: (1) to determine the recovery of 15N-labelled fertilizers applied to barley growing on artificially eroded soil, and (2) to compare N losses from nitrate- and ammonia-based N fertilizers. Field experiments were conducted in north-central Alberta in 1991 and 1992 on an Orthic Gray Luvisol (Site 1) and on an Eluviated Black Chernozem (Site 2) soil. At each site, a factorial experiment of three levels of artificial erosion (0, 10 and 20 cm) and three N sources (KNO3, urea, and control) was laid out as a split-plot design with four replications. The 15N-labelled fertilizers (5.63 atom % abundance) were banded in June 1991 at 150 kg N ha−1 within 46-cm by 46-cm steel frame microplots. The proportion of added N recovered by barley (Hordeum vulgare L.) was not affected by erosion level. Periodical water saturation and NO3− availability suggested denitrification as a major mechanism of N loss. The N losses ranged from 12 to 51 g N ha−1 in 1991 and 20 to 80 kg N ha−1 over the 2-yr period, but the N losses did not relate to erosion level. The N losses after 2 yr were greater from KNO3 than from urea at Site 1. Most of the added 15N was found in the surface 0- to 15-cm layer, but amounts of 15N were detected in the 15- to 30-cm or 30- to 45-cm layers. The results call for continued development of N management techniques geared to optimize crop growth and minimize losses from fields. Key words: Artificial erosion, barley, fate of applied N, 15N-labelled fertilizers, N immobilization, N loss

scholarly journals The effect of work level and dietary intake on sweat nitrogen losses in a hot climate

1972 ◽  
Vol 27 (3) ◽  
pp. 543-552 ◽  
Author(s):  
J. S. Weiner ◽  
J. O. C. Willson ◽  
Hamad El-Neil ◽  
Erica F. Wheeler
Keyword(s):  
Normal Diet ◽  
Physical Work ◽  
N Loss ◽  
N Losses ◽  
Total N ◽  
Adequate Diet ◽  
N Concentration ◽  
Hot Climate ◽  
Rate Of Increase ◽  
Work Level

1. Nitrogen intakes, and N output in urine, faeces and sweat have been measured in six young Tanzanian men who were accustomed to a hot climate. The measurements were done while the subjects were receiving first a normal and then a low-N diet; and when they were performing moderate physical work, and had undergone a period of acclimatization.2. When the subject were acclimatized and working on a normal diet, their sweat output increased, with a fall in its N concentration. Total sweat N loss increased from an average of 0.10 to 0.71 g/d.3. The effect of the low-N diet was to decrease both the sweat N concentration, and the rate of increase of total N loss in sweat, as sweat volume increased.4. It is estimated that maximum sweat N losses would not exceed 1 g/d on an adequate diet, or 0.5 g/d on a low-protein diet. Our results provide no basis for recommending extra protein allowances to cover sweat N losses for workers in tropical climates.

scholarly journals Shallow soil moisture – ground thaw interactions and controls – Part 2: Influences of water and energy fluxes

2010 ◽  
Vol 7 (1) ◽  
pp. 67-101
Author(s):  
X. J. Guan ◽  
C. Spence ◽  
C. J. Westbrook
Keyword(s):  
Soil Moisture ◽  
Peclet Number ◽  
Companion Paper ◽  
Surface Flow ◽  
Hydrological Processes ◽  
Energy Fluxes ◽  
Péclet Number ◽  
Shallow Soil ◽  
Inundation Extent ◽  
Study Sites

Abstract. The companion paper (Guan et al., 2010) demonstrated variable interactions and correlations between shallow soil moisture and ground thaw in soil filled areas along a wetness spectrum in a subarctic Canadian Precambrian Shield landscape. From wetter to drier, these included a wetland, peatland and soil filled valley. Herein, water and energy fluxes were examined for these same subarctic study sites to discern the key controlling processes on the found patterns. Results showed the key control in variable soil moisture and frost table interactions among the sites was the presence of surface water. At the peatland and wetland sites, accumulated water in depressions and flow paths maintained soil moisture for a longer duration than at the hummock tops. These wet areas were often locations of deepest thaw depth due to the transfer of latent heat accompanying lateral surface runoff. Although the peatland and wetland sites had large inundation extent, modified Péclet numbers indicated the relative influence of external and internal hydrological processes at each site were different. Continuous inflow from an upstream lake into the wetland site caused advective and conductive thermal energies to be of equal importance to conductive ground thaw. The absence of continuous surface flow at the peatland and valley sites led to dominance of conductive thermal energy over advective energy for ground thaw. The results suggest that the modified Péclet number could be a very useful parameter to differentiate landscape components in modeling frost table heterogeneity. The calculated water and energy fluxes, and the modified Péclet number provide quantitative explanations for the shallow soil moisture-ground thaw patterns by linking them with hydrological processes and hillslope storage capacity.

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