scholarly journals Nitrogen and Phosphorus Export After Flooding of Agricultural Land by Coastal Managed Realignment

2020 ◽  
Author(s):  
Erik Kristensen ◽  
Cintia O. Quintana ◽  
Thomas Valdemarsen ◽  
Mogens R. Flindt
Keyword(s):  
Agricultural Land ◽  
Nitrogen And Phosphorus ◽  
Managed Realignment ◽  
Phosphorus Export

scholarly journals Evidence of Phosphate Mining and Agriculture Influence on Concentrations, Forms, and Ratios of Nitrogen and Phosphorus in a Florida River

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1064
Author(s):  
Shuiwang Duan ◽  
Kamaljit Banger ◽  
Gurpal S. Toor
Keyword(s):  
Agricultural Land ◽  
Water Discharge ◽  
Mining Area ◽  
Specific Conductance ◽  
Organic N ◽  
Wet Season ◽  
Nitrogen And Phosphorus ◽  
Total N ◽  
Phosphate Mining ◽  
Molar Ratios

Florida has a long history of phosphate-mining, but less is known about how mining affects nutrient exports to coastal waters. Here, we investigated the transport of inorganic and organic forms of nitrogen (N) and phosphorus (P) over 23 sampling events during a wet season (June–September) in primary tributaries and mainstem of Alafia River that drains into the Tampa Bay Estuary. Results showed that a tributary draining the largest phosphate-mining area (South Prong) had less flashy peaks, and nutrients were more evenly exported relative to an adjacent tributary (North Prong), highlighting the effectiveness of the mining reclamation on stream hydrology. Tributaries draining > 10% phosphate-mining area had significantly higher specific conductance (SC), pH, dissolved reactive P (DRP), and total P (TP) than tributaries without phosphate-mining. Further, mean SC, pH, and particulate reactive P were positively correlated with the percent phosphate-mining area. As phosphate-mining occurred in the upper part of the watershed, the SC, pH, DRP, and TP concentrations increased downstream along the mainstem. For example, the upper watershed contributed 91% of TP compared to 59% water discharge to the Alafia River. In contrast to P, the highest concentrations of total N (TN), especially nitrate + nitrite (NOx–N) occurred in agricultural tributaries, where the mean NOx–N was positively correlated with the percent agricultural land. Dissolved organic N was dominant in all streamwaters and showed minor variability across sites. As a result of N depletion and P enrichment, the phosphate-mining tributaries had significantly lower molar ratios of TN:TP and NOx–N:DRP than other tributaries. Bi-weekly monitoring data showed consistent increases in SC and DRP and a decrease in NOx–N at the South Prong tributary (highest phosphate-mining area) throughout the wet season, and different responses of dissolved inorganic nutrients (negative) and particulate nutrients (positive) to water discharge. We conclude that (1) watersheds with active and reclaimed phosphate-mining and agriculture lands are important sources of streamwater P and N, respectively, and (2) elevated P inputs from the phosphate-mining areas altered the N:P ratios in streamwaters of the Alafia River.

scholarly journals Evaluating the Impacts of Agriculture to Groundwater Pollution in a Shallow Aquifer in Eastern Croatia

2011 ◽  
Vol 68 (2) ◽  
Author(s):  
Vilim FILIPOVIĆ ◽  
Dragutin PETOŠIĆ ◽  
Ivan ŠIMUNIĆ ◽  
Ivan MUSTAĆ ◽  
Zlatko SVEČNJAK ◽  
...  
Keyword(s):  
Groundwater Pollution ◽  
Agricultural Land ◽  
Shallow Aquifer ◽  
Nitrogen And Phosphorus ◽  
Potential Threat ◽  
Investigation Area ◽  
Groundwater Samples ◽  
The Mean ◽  
Phosphorus Levels ◽  
Observation Period

Agricultural activities are frequently associated with groundwater pollution. In this study, the goal is to evaluate the nitrate and phosphorus levels and it's impact to the groundwater. The investigation was located in the Eastern Croatia in the area of 6.600 ha of mainly agricultural land. Groundwater quality in the countertop part of the soil profile to 4.0 m depth was monitored by 40 installed hydropedological piezometers. Sampling water from piezometers was carried out every 60 days. In the groundwater samples nitrate, nitrite, ammonia and orthophosphate were analyzed. According to the indicators it was confirmed that at all locations during the observation period mean concentrations of NH4-N, NO3-N, total nitrogen (N) and phosphorus (P) in the groundwater from piezometers occasionally exceeded the value of maximum allowable concentration (MAC) which is prescribed by the Regulations. The mean concentrations of NO3-N were consistent and varied in the range from 2.42 to 4.61 mg NO3-N/l, the mean concentrations of nitrogen from ammonia exceed the permissible value (NH4-N) throughout the year, the average being higher than MAC (0.50 mg NH4-N/l) and were within the range of 0.57 mg NH4-N/l in to 1.21 mg NH4-N/l. The maximum concentration of phosphorus in groundwater were in the range of values from 0.40 to 1.11 mg P/l. Observation of traditional agricultural production in the investigation area with emphasis on leaching of nitrogen and phosphorus shows that it represents a potential threat to the future pollution of groundwater with nitrogen with phosphorus.

A meta-analysis of carbon, nitrogen and phosphorus change in response to conversion of grassland to agricultural land

Geoderma ◽  
2020 ◽  
Vol 363 ◽  
pp. 114149 ◽  
Author(s):  
Shucheng Li ◽  
Junhu Xu ◽  
Shiming Tang ◽  
Qiuwen Zhan ◽  
Qinghai Gao ◽  
...  
Keyword(s):  
Agricultural Land ◽  
Meta Analysis ◽  
Nitrogen And Phosphorus

scholarly journals Land‐use dominates climate controls on nitrogen and phosphorus export from managed and natural Nordic headwater catchments

2020 ◽  
Vol 34 (25) ◽  
pp. 4831-4850
Author(s):  
Heleen A. Wit ◽  
Ahti Lepistö ◽  
Hannu Marttila ◽  
Hannah Wenng ◽  
Marianne Bechmann ◽  
...  
Keyword(s):  
Land Use ◽  
Nitrogen And Phosphorus ◽  
Headwater Catchments ◽  
Climate Controls ◽  
Phosphorus Export

scholarly journals Heterogeneity and Anthropogenic Impacts on a Small Lowland Stream

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2002
Author(s):  
Somlyai ◽  
Berta ◽  
Nagy ◽  
Dévai ◽  
Ács ◽  
...  
Keyword(s):  
Agricultural Land ◽  
Human Impacts ◽  
Anthropogenic Impacts ◽  
Anthropogenic Effects ◽  
Nitrogen And Phosphorus ◽  
Buffer Zones ◽  
Small Surface ◽  
Great Heterogeneity ◽  
Physical And Chemical Variables ◽  
Physical And Chemical

During our work, we investigated the physical and chemical variables of a small surface watercourse to investigate how different anthropogenic effects affect its water quality. Along this small watercourse, there are well-separated areas that are affected by various anthropogenic effects. In addition to its origin and branches, in many places it is surrounded by agricultural land with insufficient buffer zones, which burdens the small watercourse with nitrogen and phosphorus forms. In the lower stages, artificial damming inhibits the natural flow of the Tócó Canal, thereby creating eutrophicated stagnant water areas. This is further strengthened by, in many cases, illegal communal and used water intake that further burdens the small watercourse. Considering the experience of our investigation, it can be stated that the examined small watercourse could barely suffer human impacts, and it could be described with great heterogeneity using physical and chemical variables. We experienced that this heterogeneity caused by anthropogenic effects appeared in all hydrologic states and seasons. Furthermore, our research showed that these small watercourses had such high heterogeneity that their monitoring and examination should be taken just as seriously as when it comes to larger watercourses.

Long-Term Observations of Nitrogen and Phosphorus Export in Paired-Agricultural Watersheds under Controlled and Conventional Tile Drainage

2015 ◽  
Vol 44 (5) ◽  
pp. 1589-1604 ◽  
Author(s):  
M. D. Sunohara ◽  
N. Gottschall ◽  
G. Wilkes ◽  
E. Craiovan ◽  
E. Topp ◽  
...  
Keyword(s):  
Tile Drainage ◽  
Agricultural Watersheds ◽  
Nitrogen And Phosphorus ◽  
Phosphorus Export

Phosphorus export from agricultural land: a simple approach

2008 ◽  
Vol 101 (2) ◽  
pp. 270-280 ◽  
Author(s):  
A. Leone ◽  
M.N. Ripa ◽  
L. Boccia ◽  
A. Lo Porto
Keyword(s):  
Agricultural Land ◽  
Simple Approach ◽  
Phosphorus Export

Monitoring of groundwater, morphological and ecological development of the Perkpolder managed realignment following tidal restoration

2020 ◽  
Author(s):  
Wietse van de Lageweg ◽  
Joao Salvador de Paiva ◽  
Jebbe van der Werf ◽  
Lodewijk de Vet ◽  
Perry de Louw ◽  
...  
Keyword(s):  
The Netherlands ◽  
Sea Level Rise ◽  
Sea Level ◽  
Agricultural Land ◽  
Sediment Dynamics ◽  
Scheldt Estuary ◽  
Biologically Active ◽  
Management Approach ◽  
Managed Realignment ◽  
Tidal Area

<p>Innovative, sustainable and cost-effective coastal protection solutions are required to adapt to environmental change and enhance ecosystem functioning. Managed realignment is an example of an ecosystem engineering coastal management approach motivated by concerns about biological conservation and sea-level rise. It involves relocating the line of defense landward, thereby mimicking what would normally happen with marine environments during a period of sea-level rise. The retreat allows new salt marshes to develop offering a range of ecosystem services. Despite the ongoing execution of managed realignment projects in, amongst others, the UK, Germany, the Netherlands, Belgium and Spain, it remains unclear whether management realignment is able to deliver on the expected socio-economic and environmental benefits.</p><p>Here we report on the short-term (0-4 years) development of physical and ecological processes of the Perkpolder managed realignment area in the Scheldt estuary, the Netherlands, following tidal restoration in 2015. The overarching goal of the Perkpolder project was to realize 75 hectares of low-dynamic tidal nature contributing to Natura2000 conservation goals for the Western Scheldt estuary as well as serving as a compensation measure for the extension of the navigation channel for the Antwerp harbor.</p><p>The Perkpolder managed realignment is considered a unique opportunity to monitor and study the biotic and abiotic changes in an area transforming from a freshwater agricultural area to a tidal saline natural area. An interdisciplinary monitoring framework was set up to record the abiotic and biotic developments of the Perkpolder realignment area, particularly focusing on morphological changes, colonization of the new tidal area by benthic macrofauna and vegetation, and its function as foraging area for water birds. Also the groundwater system is studied and its effect on the surrounding agricultural land.</p><p>A mitigation measure, called ‘SeepCat’, was installed on the border of the new tidal area and the agricultural land to protect the freshwater lens used by farmers for irrigation. The lens was expected to shrink by this local sea level rise. From the groundwater measurements, it was concluded that the SeepCat system was functioning well enough to compensate for the effects of the new tidal area.</p><p>Using a Delft3D numerical model simulation, it was shown that the design of the morphological template has a large impact on the rates of morphological change. Additionally, the sediment import, estimated from SPM concentration and discharge measurements, varied strongly in time, and sediment was also being exported for a number of tides. Controlled laboratory experiments show that seedlings of pioneer marsh plant species survive best in a well-drained soil without sediment dynamics. Yet, seedlings can tolerate some moderate sediment dynamics. From a benthic community perspective, the development of the managed realignment Perkpolder is encouraging. A biologically active intertidal area has formed within a short time frame. Within 3 years, the benthic macroinfaunal community shows a development towards a community found on natural tidal mudflats and is expected to reach a stable community in years rather than decades. The area is also frequently visited by birds, which forage during low tide and rest on the surrounding dikes during high tide.</p>

scholarly journals Spatiotemporal evolution of ecosystem services in South China Karst and driving mechanism

2021 ◽  
Author(s):  
Shihao ZHANG
Keyword(s):  
Soil Conservation ◽  
Driving Forces ◽  
Driving Mechanism ◽  
Spatiotemporal Evolution ◽  
Nitrogen And Phosphorus ◽  
Rocky Desertification ◽  
Natural Factors ◽  
Increasing Trend ◽  
Main Factors ◽  
Phosphorus Export

To explore the above-mentioned problems, we analyzed the spatiotemporal evolution of ES (WY, SC, NPP, nitrogen and phosphorus export, HQ, CS, and Bio) in SCK, and combined policy (GFG), natural factors (MP, MT, PET, and VC) and human activities (PD, NL, GDP, FL, Forest, Grass, BL and UL) discussed the driving forces of ES changes in different landscapes. The results showed that from 1982 to 2018, WY, nitrogen Export, HQ, CS and Bio in SCK showed a decreasing trend, while SC and NPP showed an increasing trend. WY had a large decrease in all ES, a decrease of 13.23%; while NPP had a large increase, an increase of 19.16%. Comparing different landscape, the study found that SC, NPP, nitrogen and phosphorus export, CS and Bio in non-karst were higher than in karst, while HQ was the opposite. This study showed that natural factors (MP, MT, PET and VC) are the main factors of affecting ES in SCK, and found that the driving factors of ES indicators in different landscapes (karst and non-karst) are not the same. The study emphasized mountain enclosure for afforestation in karst suitable forests and barren hills to restore ES; fast-growing and pioneer species with a large amount of fine roots were planted in wasteland and rocky desertification areas to increase soil conservation services in the early ecosystems; through the policy of migration and employment, the human disturbance to nature can be reduced and habitat quality and biodiversity service can be improved.

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