Effects of dynamic factors of erosion on soil nitrogen and phosphorus loss under freeze-thaw conditions

2020 ◽  
Author(s):  
yuting cheng ◽  
peng li ◽  
Guoce Xu ◽  
yixin zhang
Keyword(s):  
Water Content ◽  
Total Phosphorus ◽  
Nitrogen And Phosphorus ◽  
Phosphorus Loss ◽  
P Loss ◽  
Total Runoff ◽  
Dynamic Factors ◽  
Sediment Loss ◽  
The Relationship ◽  
Rainfall Erosion

<p>Soil erosion is one of the primary environmental problems in China, and it can lead to serious water, soil, and nutrient losses. However, the mechanism of action of the dynamic factors of erosion on nitrogen (N) and phosphorus (P) loss remains unclear. In this study, a series of laboratory experiments were carried out to characterize the N and P loss and its influencing factors under freeze–thaw conditions. Two slope treatments (i.e. LS: loess and FTS: freeze–thaw soil) and five soil water content (SWC) (i.e. 10%, 15%, 20%, 25% and 30%) were considered. The results showed that the total runoff was higher under 30% SWC and lower under 20% SWC for the LS and FTS treatments. The freeze–thaw action caused higher sediment loss under low water content (10% and 15%). The runoff-associated total nitrogen (RTN), runoff-associated total phosphorus (RTP), and sediment-associated total phosphorus (STP) loss rate showed a larger fluctuation for FTS than for LS. The freeze–thaw action not only caused the instability of the nitrogen and phosphorus loss behavior but also caused increased diversity among individual samples. The soil erodibility, runoff energy, and runoff power were important dynamic factors associated with erosion, and the freeze–thaw action has a very large impact on these factors. For the LS treatments, the SWC could explain 60% of the variation in RTN loss and 63% of the variation in RTP; the runoff and infiltration both explained 90% of the variation in STN loss and the runoff time explained 97% of the variation in STP. For the FTS treatments, the runoff time explained 63% of the variation in STN and 53% of the variation in STP. The results enable us to understand further the relationship between dynamic factors of rainfall erosion and nitrogen and phosphorus loss under freeze–thaw conditions.</p>

Effects of dynamic factors of erosion on soil nitrogen and phosphorus loss under freeze-thaw conditions

Geoderma ◽  
2021 ◽  
Vol 390 ◽  
pp. 114972
Author(s):  
Yuting Cheng ◽  
Peng Li ◽  
Guoce Xu ◽  
Xiukang Wang ◽  
Zhanbin Li ◽  
...  
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen And Phosphorus ◽  
Phosphorus Loss ◽  
Freeze Thaw ◽  
Dynamic Factors

The Relationship of Chlorophyll-A, Total Nitrogen and Total Phosphorus in Wuliangsuhai Lake

2014 ◽  
Vol 955-959 ◽  
pp. 1393-1396 ◽  
Author(s):  
Yun Hao ◽  
Rui Hong Yu ◽  
Yu Jin Zhang ◽  
Huan Yang
Keyword(s):  
Regression Analysis ◽  
Chlorophyll A ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Monitoring Data ◽  
Nitrogen And Phosphorus ◽  
Algae Growth ◽  
Relationship Of ◽  
The Relationship

This paper studied the relationship of chlorophyll-a, total nitrogen (TN) and total phosphorus (TP) concentration based on the conventional monitoring data in 2013. The results showed that the concentration of chlorophyll-a (Chl.a) had obvious correlation with TN, TP in July and August, and there was no relationship in October. Furthermore, content of nitrogen is more relevant to chlorophyll-a than phosphorus by regression analysis. Therefore, it was indicated that nitrogen and phosphorus nutrients had intimated relationships with algae growth.

scholarly journals Study on Characteristics of Nitrogen and Phosphorus Loss under an Improved Subsurface Drainage

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1467 ◽  
Author(s):  
Tao ◽  
Wang ◽  
Guan ◽  
Xu ◽  
Chen ◽  
...  
Keyword(s):  
Total Nitrogen ◽  
Total Phosphorus ◽  
Nitrate Nitrogen ◽  
Subsurface Drainage ◽  
Ammonia Nitrogen ◽  
Nitrogen And Phosphorus ◽  
Phosphorus Loss ◽  
Soluble Reactive Phosphate ◽  
Reactive Phosphate ◽  
Nitrogen Concentrations

Agricultural drainage plays an effective role in preventing waterlogging and salinity disasters and also is the main transport pathway for agricultural non-point source pollutants into rivers and lakes. Hence, the water quality of agricultural drainage should be a point of focus. In this paper, nitrogen and phosphorus loss under improved subsurface drainage with different filter materials (gravel, layered sand-gravel, mixed sand-gravel, straw) were studied by a three-year field experiment (2016–2018) compared with the conventional subsurface drainage. The pH values, total nitrogen, ammonia nitrogen, nitrate nitrogen, total phosphorus and soluble reactive phosphate were considered. The results showed that the nitrogen and phosphorus concentrations of drain outflow under improved subsurface drainage with gravel filter were larger than that with layered sand-gravel filter and mixed sand-gravel filter. The improved subsurface drainages with layered sand-gravel filter and mixed sand-gravel filter had an effect on reducing the ammonia nitrogen, total phosphorus and soluble reactive phosphate concentrations of the outflow. Meanwhile, the characteristics of nitrogen and phosphorus loss under the improved subsurface drainage with straw filter were different from that with layered sand-gravel filter and mixed sand-gravel filter. For the improved subsurface drainage with layered sand-gravel filter outflow, the ammonia nitrogen, total phosphorus, and soluble reactive phosphate concentrations were about 13%–78%, 38%–63%, 40%–68% less, and total nitrogen, nitrate nitrogen concentrations were 24%–80%,18%–96% more than that under conventional subsurface drainage. Meanwhile, for the improved subsurface drainage with straw filter outflow, compared with conventional subsurface drainage outflow, the percentage changes of the total nitrogen, nitrate nitrogen, ammonia nitrogen, total phosphorus and the soluble reactive phosphate concentrations were about −76%–62%, −77%–78%, −152%–−274%, −103%–−400% and −221%–−291%, respectively. Additionally, in the outflow of all subsurface drainage patterns, there were much higher total nitrogen and nitrate nitrogen concentrations which should be focused on and the agricultural water management should be adopted.

Mechanism Analysis and Experimental Research on the Interception of Nitrogen and Phosphorus Pollutants by Gullies in Northern China

2011 ◽  
Vol 250-253 ◽  
pp. 3392-3396
Author(s):  
Yu Jia Song ◽  
Hui Qing Liu
Keyword(s):  
Total Phosphorus ◽  
Nitrate Nitrogen ◽  
Northern China ◽  
Careful Analysis ◽  
Ammonia Nitrogen ◽  
Mechanism Analysis ◽  
Nitrogen And Phosphorus ◽  
Urban Sewage ◽  
Control Section ◽  
Nitrogen Pollutants

The discharge of urban sewage and agricultural non-point source pollutants is the main reason causing eutrophication in gullies in most cities of northern China. Based on a careful analysis on the ecological structure and ecological characteristics of a gully, this article preliminarily studies the interception and degradation mechanisms of nitrogen pollutants by the gully. Meanwhile, to take gullies in Changchun as the object of the study, this article carries out an experiment on the interception effect of nitrogen pollutants by gullies. This experiment respectively establishes a control section in the upper and lower reaches of a gully, and takes water samples four times in each section from May to August to determine total nitrogen, total phosphorus, nitrate nitrogen, ammonia nitrogen and salinity. The result shows: the gully plays some role in the interception of pollutants; total phosphorus accounts for the largest interception in pollutants in the experimented gully section, with the relative interception rate of 27.46%, followed by ammonia nitrogen, with the interception rate of 21.80%, which is the result of the combined effects of aquatic plants, microorganisms and sediment in the gully.

Carbon balance in relation to drying in four epiphytic mosses growing in different vertical ranges

1979 ◽  
Vol 57 (19) ◽  
pp. 1994-1998 ◽  
Author(s):  
Peter L. Tobiessen ◽  
Nancy G. Slack ◽  
Keith A. Mott
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Carbon Balance ◽  
The Other ◽  
Moss Species ◽  
Relationship Of ◽  
The Relationship ◽  
Neckera Pennata ◽  
Lower Water Content ◽  
Photosynthesis And Respiration

The response of photosynthesis and respiration to drying was measured in four species of epiphytic mosses, Ulota crispa (Hedw.) Brid., Neckera pennata Hedw., Anomodon rugellii (C. Mull.) Keissl., and Plagiomnium cuspidatum (Hedw.) T. Kop., from habitats along a desiccation gradient. There was little difference among the mosses in these responses. The relationship of water content to water potential did differ among the mosses, with Plagiomnium, the facultative epiphyte, showing a typical response of more mesic species and the other three showing a more xeric response, i.e., water potential does not begin to fall steeply until a lower water content is reached in Ulota, Neckera, and Anomodon. Both photosynthesis and respiration in all four moss species were quite sensitive to moderate water stress.

Soil Water Characteristic Curve and its Applications in Tunnel

2011 ◽  
Vol 261-263 ◽  
pp. 1039-1043
Author(s):  
Yu You Yang ◽  
Qin Xi Zhang ◽  
Gui He Wang ◽  
Jia Xing Yu
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Land Subsidence ◽  
Unsaturated Soil ◽  
Characteristic Curve ◽  
Tunnel Construction ◽  
Coupling Theory ◽  
Engineering Analysis ◽  
Soil Water Characteristic Curve ◽  
The Relationship

A soil water characteristic curve (SWCC) can describe the relationship between unsaturated soil matric suction and water content. By analyzing and researching the test data of the soil water characteristic curve researchers can initially establish the SWCC equation and apply this equation to the actual engineering analysis. In another words, this article is based on the fluid-solid coupling theory of unsaturated soil used to analyze and study the problem of land subsidence caused by tunnel construction. Numerical calculations show that the coupling results agree well with the measured curve works.

scholarly journals Optimization of nitrogen and phosphorus removal from pig slaughterhouse and packing plant wastewater through electrocoagulation in a batch reactor

2018 ◽  
Vol 13 (5) ◽  
pp. 1
Author(s):  
Fábio Orssatto ◽  
Maria Hermínia Ferreira Tavares ◽  
Flávia Manente da Silva ◽  
Eduardo Eyng ◽  
Leandro Fleck
Keyword(s):  
Total Phosphorus ◽  
Retention Time ◽  
Batch Reactor ◽  
Maximum Efficiency ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Treatment Conditions ◽  
Surface Graph ◽  
Wide Range ◽  
Kjeldahl Nitrogen

This work evaluated the removal of total Kjeldahl nitrogen (TKN) and total phosphorus (P) through electrocoagulation and used aluminum electrodes to optimize the potential differential (pd) and hydraulic retention time (HRT) variables in a batch reactor. The experimental design used was Rotatable Central Composite Design (RCCD). The application of the electrocoagulation in the treatment of effluents from pig slaughterhouses and packing plants proved to be efficient in relation to the removal of TKN and total phosphorus, obtaining maximum efficiency equal to 67.15% and 99%, respectively. The maximum TKN removal value was found in Test 12, where treatment conditions were 30 minutes for HRT and 20 volts for pd, which corresponds to 0.86 A of electric current and a current density of 17.2 mA cm-2. For P, the only test that removed below 99% was the first. Through statistical analyses, it was only possible to obtain a mathematical model for TKN removal. While the response surface graph did not present a defined range of the best conditions for the independent variables, it was possible to observe the tendency for better removal, a wide range of pd and values over 30 minutes for retention time.

scholarly journals Ichthyometry and electrical bioimpedance analysis to estimate the body composition of tambatinga

2014 ◽  
Vol 44 (2) ◽  
pp. 279-286 ◽  
Author(s):  
Francisco Teixeira Andrade ◽  
Márvio Lobão Teixeira de Abreu ◽  
João Batista Lopes ◽  
Agustinho Valente de Figueiredo ◽  
Maria de Nazaré Bona Alencar Araripe ◽  
...  
Keyword(s):  
Body Composition ◽  
Water Content ◽  
Correlation Coefficients ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
The Body ◽  
Composition Analysis ◽  
Average Weight ◽  
Electrical Bioimpedance ◽  
The Relationship

Body composition analysis is relevant to characterize the nutritional requirements and finishing phase of fish. The aim of this study was to investigate the relationship between ichthyometric (weight, total and standard length, density and yields), bromatological (fat, protein, ash and water content) and bioelectrical-impedance-analysis (BIA) (resistance, reactance, phase angle and composition indexes) variables in the hybrid tambatinga (Colossoma macropomum × Piaractus brachypomus). In a non-fertilized vivarium, 520 juveniles were housed and fed commercial rations. Then, 136 days after hatching (DAH), 15 fish with an average weight of 37.69 g and average total length of 12.96 cm were randomly chosen, anesthetized (eugenol) and subjected to the first of fourteen fortnightly assessments (BIA and biometry). After euthanasia, the following parts were weighed: whole carcass with the head, fillet, and skin (WC); fillet with skin (FS); and the remainder of the carcass with the head (CH). Together, FS and CH were ground and homogenized for the bromatological analyses. Estimates of the body composition and yields of tambatinga, with models including ichthyometric and BIA variables, showed correlation coefficients ranging from 0.81 (for the FS yield) to 1,00 (for the total ash). Similarly, models that included only BIA variables had correlation coefficients ranging from 0.81 (FS and CH yields) to 0.98 (for the total ash). Therefore, in tambatinga, the BIA technique allows the estimation of the yield of the fillet with skin and the body composition (water content, fat, ash, and protein). The best models combine ichthyometric and BIA variables.

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