scholarly journals Nitrogen in Water-Portugal and Denmark: Two Contrasting Realities

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1114 ◽  
Author(s):  
Soraia Cruz ◽  
Cláudia M.d.S. Cordovil ◽  
Renata Pinto ◽  
António G. Brito ◽  
Maria R. Cameira ◽  
...  
Keyword(s):  
Water Quality ◽  
Surface Waters ◽  
Mineral Fertilizer ◽  
N Losses ◽  
Total N ◽  
Policy Responses ◽  
Mainland Portugal ◽  
Water Quality Status ◽  
Use Efficiency ◽  
The Impact

Agricultural activities are responsible for most of the nitrogen (N) inputs that degrade water quality. To elucidate the drivers leading to N pressures on water, we examined the resulting state of surface waters in terms of N concentrations, the impact of this on water quality status and policy responses to these constraints across different climatic and management conditions. Portugal and Denmark were chosen as contrasting case studies for the Driver-Pressure-State-Impact-Response (DPSIR) analysis. Our results showed reductions of 39% and 25% in the use of mineral fertilizer in Portugal and Denmark, respectively, between 2000 and 2010. The N surplus in Portugal varied between 15 and 30 kg N ha−1 between 1995 and 2015. In Denmark, in 2015, this amount was 70 kg N ha−1, representing a 53% decrease from the 1990 value. The average amount of total N discharged to surface waters was 7 kg ha−1 for mainland Portugal in 2015 and 14.6 kg ha−1 for Denmark in 2014. These reductions in the N surplus were attributed to historical policies aimed at N pressure abatement. In Denmark, N losses are expected to decline further through the continuation or improvement of existing national action plans. In Portugal, they are expected to decline further due to the expansion of Nitrate Vulnerable Zones and the introduction of targeted policies aimed at improving N use efficiency and reducing losses to water.

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.

Soil Type Modifies the Impacts of Warming and Snow Exclusion on Carbon and Nutrient Losses

2021 ◽  
Author(s):  
Stephanie M. Juice ◽  
Paul G. Schaberg ◽  
Alexandra M. Kosiba ◽  
Carl E. Waite ◽  
Gary J. Hawley ◽  
...  
Keyword(s):  
Climate Change ◽  
Nutrient Cycling ◽  
Soil Type ◽  
Soil Characteristics ◽  
Nutrient Loss ◽  
Climate Projections ◽  
Nutrient Losses ◽  
N Losses ◽  
Total N ◽  
The Impact

Abstract The varied and wide-reaching impacts of climate change are occurring across heterogeneous landscapes. Despite the known importance of soils in mediating biogeochemical nutrient cycling, there is little experimental evidence of how soil characteristics may shape ecosystem response to climate change. Our objective was to clarify how soil characteristics modify the impact of climate changes on carbon and nutrient leaching losses in temperate forests. We therefore conducted a field-based mesocosm experiment with replicated warming and snow exclusion treatments on two soils in large (2.4 m diameter), in-field forest sapling mesocosms. We found that nutrient loss responses to warming and snow exclusion treatments frequently varied substantially by soil type. Indeed, in some cases, soil type nullified the impact of a climate treatment. For example, warming and snow exclusion increased nitrogen (N) losses on fine soils by up to four times versus controls, but these treatments had no impact on coarse soils. Generally, the coarse textured soil, with its lower soil-water holding capacity, had higher nutrient losses (e.g., 12-17 times more total N loss from coarse than fine soils), except in the case of phosphate, which had consistently higher losses (23-58%) from the finer textured soil. Furthermore, the mitigation of nutrient loss by increasing tree biomass varied by soil type and nutrient. Our results suggest that potentially large biogeochemical responses to climate change are strongly mediated by soil characteristics, providing further evidence of the need to consider soil properties in Earth system models for improving nutrient cycling and climate projections.

scholarly journals Assessment of the Impact of Forestry and Settlement-Forest Use of the Catchments on the Parameters of Surface Water Quality: Case Studies for Chechło Reservoir Catchment, Southern Poland

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 964 ◽  
Author(s):  
Andrzej Bogdał ◽  
Andrzej Wałęga ◽  
Tomasz Kowalik ◽  
Agnieszka Cupak
Keyword(s):  
Water Quality ◽  
Total Phosphorus ◽  
Surface Waters ◽  
Forest Cover ◽  
Statistical Tests ◽  
Surface Water Quality ◽  
Anthropogenic Factors ◽  
Multivariate Statistical ◽  
Forest Use ◽  
The Impact

The aim of the study was to determine the impact of natural and anthropogenic factors on the values of 22 quality indicators of surface waters flowing out of two small catchments differing in physiographic parameters and land use, in particular forest cover and urbanization of the area. The research was carried out in the years 2012–2014 at four measurement-control points located on the Chechło river and the Młoszówka stream (Poland), which are the main tributaries of the retention reservoir. Basic descriptive statistics, statistical tests, as well as cluster analysis and factor analysis were used to interpret the research results. The water that outflowed from the forestry-settlement catchment of the Młoszówka stream contained higher concentrations of total phosphorus, phosphates, nitrite, and nitrate nitrogen and salinity indicators than outflow from the Chechło river. Water from the Młoszówka stream was characterized by more favourable oxygen conditions. Higher oxygen concentration in the catchment influenced a large slope of the watercourse and thus higher water velocity, which is promoted by the mixed process. In the case of the forest catchment of the Chechło river, the water quality was generally better than in the Młoszówka stream, mainly in cases of total suspended solids TSS, total phosphorus TP, phosphates PO43−, total nitrogen TN, nitrite N–NO2−, nitrate N–NO3−, and salinity parameters. Despite it being a short section of the river taken into the study, favourable self-purification processes like mixed, nitrification, and denitrification were observed in its water. The research shows that forest areas have a positive effect on the balance of most substances dissolved in water, and natural factors in many cases shape the quality and utility values of surface waters on an equal footing with anthropogenic factors. In the case of a large number of examined parameters and complex processes occurring in water, the interpretation of the results makes it much easier by applying multivariate statistical methods.

The nitrogen footprint of food products in the European Union

2013 ◽  
Vol 152 (S1) ◽  
pp. 20-33 ◽  
Author(s):  
A. LEIP ◽  
F. WEISS ◽  
J. P. LESSCHEN ◽  
H. WESTHOEK
Keyword(s):  
European Union ◽  
Crop Yields ◽  
Essential Element ◽  
Mineral Fertilizer ◽  
N Leaching ◽  
The European Union ◽  
N Losses ◽  
Total N ◽  
Reactive N ◽  
Livestock Products

SUMMARYNitrogen (N) is an essential element for plants and animals. Due to large inputs of mineral fertilizer, crop yields and livestock production in Europe have increased markedly over the last century, but as a consequence losses of reactive N to air, soil and water have intensified as well. Two different models (CAPRI and MITERRA) were used to quantify the N flows in agriculture in the European Union (EU27), at country-level and for EU27 agriculture as a whole, differentiated into 12 main food categories. The results showed that the N footprint, defined as the total N losses to the environment per unit of product, varies widely between different food categories, with substantially higher values for livestock products and the highest values for beef (c. 500 g N/kg beef), as compared to vegetable products. The lowest N footprint of c. 2 g N/kg product was calculated for sugar beet, fruits and vegetables, and potatoes. The losses of reactive N were dominated by N leaching and run-off, and ammonia volatilization, with 0·83 and 0·88 due to consumption of livestock products. The N investment factors, defined as the quantity of new reactive N required to produce one unit of N in the product varied between 1·2 kg N/kg N in product for pulses to 15–20 kg N for beef.

scholarly journals The impact of wildfire on biogeochemical fluxes and water quality on boreal catchments

2020 ◽  
Author(s):  
Gustaf Granath ◽  
Christopher D. Evans ◽  
Joachim Strengbom ◽  
Jens Fölster ◽  
Achim Grelle ◽  
...  
Keyword(s):  
Water Quality ◽  
Temporal Dynamics ◽  
Biogeochemical Cycles ◽  
First Year ◽  
Co2 Uptake ◽  
N Losses ◽  
Nutrient Pools ◽  
Terrestrial Environments ◽  
Ecosystem Level ◽  
The Impact

Abstract. Wildfires are the major disturbance in boreal ecosystems, and are of great importance for the biogeochemical cycles of carbon (C) and nutrients. However, these fire-induced impacts are hard to quantify and rarely assessed together at an ecosystem level incorporating both aquatic and terrestrial environments. Following a wildfire in Sweden in an area with ongoing monitoring, we conducted a pre- and post-fire multi-catchment investigation of element losses (combustion and leaching), and impacts on water quality. Direct C and nitrogen (N) losses through combustion were ca. 4500 g m−2 and 100 g m−2, respectively. Net CO2 loss associated with soil and biomass respiration was ~ 150 g C m−2 during the first year, but the ecosystem started to show net CO2 uptake in June three years post-fire. Aquatic C and N losses during the first 12 months were 7 g m−2 and 0.6 g m−2, respectively. Hence, soil respiration comprised a non-negligible part of the post-fire C loss, whereas aquatic C losses were minor, and did not increase post-fire. However, other elements (e.g., Ca, S) exhibited ecologically relevant increases in fluvial export and concentration, with large peaks in the immediate post-fire period. The temporal dynamics of stream concentrations suggest the presence of faster- and slower-release nutrient pools with half-lives of around 2 weeks and 4 months, which we attribute to physicochemically and biologically mediated mobilisation processes, respectively. Three years after the fire, it appears that biogeochemical cycles have largely returned to pre-fire conditions, but there is still net release of CO2.

scholarly journals Assessment of the Impact of Land Cover Type on the Water Quality in Lake Tondano Using a SWAT Model

2021 ◽  
Vol 56 (1) ◽  
Author(s):  
Moh Sholichin ◽  
Tri Budi Prayogo
Keyword(s):  
Water Quality ◽  
Land Cover ◽  
Agricultural Land ◽  
Assessment Tool ◽  
Swat Model ◽  
Coefficient Of Determination ◽  
Organic N ◽  
Lake Water Quality ◽  
Total N ◽  
The Impact

Lake Tondano is the largest natural lake in North Sulawesi, Indonesia, which functions as a provider of clean water, hydroelectric power, rice field irrigation, inland fisheries, and tourism. This research aims to determine the effect of land cover types from the Tondano watershed on the lake water quality. The Soil and Water Assessment Tool (SWAT) model was used to evaluate the rate of soil erosion and the pollutant load of various land types in the watershed during the last ten years. Rainfall data is obtained from two rainfall stations, namely Paleloan Station and Noonan Station. The model is calibrated and validated before being used for analysis. We use climatological data from 2014 to 2019. The process of the SWAT model calibration and validation was carried out with the statistical formulas of the coefficient of determination (R2) and Nash-Sutcliffe efficiency (NSE). The results show that the potential for pollution load from the Tondao watershed is organic N of 0.039 kg/ha and organic P of 0.006 kg/ha coming from the agricultural land. The results of this study conclude that the fertility conditions of Lake Tondano are at the eutrophic level, where the pollutant inflow is collected in the lake waters, especially for the parameters of total N (1503697.44kg/year) and total P (144831.36kg/year). The SWAT simulation results show deviation between the modeling and field data collected with the value of R2 = 0.9303, and the significant level ≤ 10.

Agricultural land use and N losses to water: the case study of a fluvial park in Northern Italy

2003 ◽  
Vol 47 (7-8) ◽  
pp. 275-282 ◽  
Author(s):  
F. Morari ◽  
E. Lugato ◽  
M. Borin
Keyword(s):  
Water Quality ◽  
Best Management Practices ◽  
Water Resource Management ◽  
Management Practices ◽  
Agricultural Land ◽  
Subsurface Water ◽  
Agricultural Systems ◽  
N Losses ◽  
Positive Effects ◽  
The Impact

An integrated water resource management programme has been under way since 1999 to reduce agricultural water pollution in the River Mincio fluvial park. The experimental part of the programme consisted of: a) a monitoring phase to evaluate the impact of conventional and environmentally sound techniques (Best Management Practices, BMPs) on water quality; this was done on four representative landscape units, where twelve fields were instrumented to monitor the soil, surface and subsurface water quality; b) a modelling phase to extend the results obtained at field scale to the whole territory of the Mincio watershed. For this purpose a GIS developed in the Arc/Info environment was integrated into the CropSyst model. The model had previously been calibrated to test its ability to describe the complexity of the agricultural systems. The first results showed a variable efficiency of the BMPs depending on the interaction between management and pedo-climatic conditions. In general though, the BMPs had positive effects in improving the surface and subsurface water quality. The CropSyst model was able to describe the agricultural systems monitored and its linking with the GIS represented a valuable tool for identifying the vulnerable areas within the watershed.

Aquaculture impacts on the algal and bacterial communities in a small boreal forest lakeThis paper is part of the series “Forty Years of Aquatic Research at the Experimental Lakes Area”.

2009 ◽  
Vol 66 (11) ◽  
pp. 1936-1948 ◽  
Author(s):  
David L. Findlay ◽  
Cheryl L. Podemski ◽  
Susan E.M. Kasian
Keyword(s):  
Water Quality ◽  
Nutrient Loading ◽  
Stocking Density ◽  
Freshwater Ecosystem ◽  
Experimental Lakes Area ◽  
Fish Food ◽  
Total N ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Northwestern Ontario ◽  
The Impact

A whole-lake experiment to examine the impacts of aquaculture on a freshwater ecosystem was conducted at the Experimental Lakes Area in northwestern Ontario, Canada. From 2003 to 2006, a 10 tonne fish capacity aquaculture cage stocked with rainbow trout ( Oncorhynchus mykiss ) was operated in Lake 375 and the impact of excess nutrients on the algal and bacteria communities was examined. The experiment was designed as a nutrient loading experiment with fish food and fish excretion the source of nutrients. Total N and P concentrations increased over the 4 years (15× and 4×, respectively). Phytoplankton biomass increased 4× annually following the start of aquaculture operation in 2003. The most dramatic responses occurred during spring and fall mixing, with blooms of chrysophytes and dinoflagellates increasing biomass by up to 12×. Bacteria biomass and densities were unaffected except for increases in late fall. Periphyton biomass was relatively unaffected except for an increase in biomass in the fourth year. The combination of a long water residence time in the lake coupled with an extremely high fish stocking density in Lake 375 resulted in an immediate impact on water quality. The results suggest that the impacts of aquaculture are accumulative and continual stocking will further impact water quality.

Nitrogen use efficiency of different slurry management in the pre-alpine grassland region – a 15N tracing experiment

2020 ◽  
Author(s):  
Marcus Zistl-Schlingmann ◽  
Steve Kwatcho-Kengdo ◽  
Mirella Schreiber ◽  
Bernd Berauer ◽  
Anke Jentsch ◽  
...  
Keyword(s):  
Climate Change ◽  
Soil Nitrogen ◽  
Nitrogen Use Efficiency ◽  
Cattle Slurry ◽  
N Losses ◽  
Nitrogen Use ◽  
Total N ◽  
Plant Nitrogen ◽  
Plant Soil ◽  
Use Efficiency

<p>Grasslands of the alpine and pre-alpine region do not only sustain economic soil functions such as fodder production for local dairy and cattle farming but also important ecological soil functions such as water and nutrient retention, erosion and flood protection and habitat provision for extraordinarily high plant and animal biodiversity. The current management in the more intensively used grasslands in this region is based on fertilization with liquid cattle slurry, which is assumed to be prone to high N leaching and gaseous N emissions with their undesired consequences for soil, air and water quality.</p><p>In order to assess the nitrogen use efficiency and trade-offs such as greenhouse gas emissions and nitrate leaching of liquid slurry surface application under the auspices of climate change, we set up a <sup>15</sup>N cattle slurry labeling experiment, combined with a space for time climate change experiment using plant-soil mesocosms and lysimeters. The <sup>15</sup>N signal was traced in the plant-soil-microbe system for an entire year to assess productivity, plant nitrogen use efficiency, soil nitrogen retention and nitrogen losses. We found surprisingly low plant nitrogen use efficiency (recovery of less than ¼ of the applied <sup>15</sup>N in harvested plant biomass), soil N retention (ca ¼ <sup>15</sup>N recovery) and high environmental N losses (ca ½ of the <sup>15</sup>N tracer remained unrecovered). The estimates of N losses based on unrecovered <sup>15</sup>N were in good agreement with independent measurements of gaseous and hydrological N losses. Due to very high productivity and associated N exports with grass harvests, total N exports exceeded total N inputs. Such soil nitrogen mining was especially pronounced in the climate change treatments and was supported by increased soil nitrogen mineralization.</p><p>We also tested alternative slurry management (slurry injection into the soil, slurry acidification) that is supposed to increase nitrogen use efficiency. Slurry acidification but not slurry injection slightly increased plant nitrogen use efficiency and reduced nitrogen losses, however could overall not prevent significant soil nitrogen mining.</p><p>Consequently, both surface application and the more modern techniques of liquid cattle slurry fertilization showed low nitrogen use efficiency and promoted soil nitrogen mining. This is asking for a re-consideration of traditional fertilization regimes based on solid manure mixed with straw, a management that over historical timescales likely contributed to the build up of the large nitrogen stocks in pre-alpine grassland soils.</p>

scholarly journals Urochloa ruziziensis responses to sources and doses of urea

2016 ◽  
Vol 20 (5) ◽  
pp. 401-407 ◽  
Author(s):  
João E. S. Lima ◽  
Adriano S. Nascente ◽  
Wilson M. Leandro ◽  
Pedro M. da Silveira
Keyword(s):  
Chlorophyll Content ◽  
Dry Matter ◽  
N Fertilization ◽  
N Losses ◽  
Total N ◽  
Rainy Period ◽  
N Sources ◽  
Use Efficiency ◽  
Tiller Density ◽  
Relative Chlorophyll Content

ABSTRACT The use of products that promote reduction of nitrogen (N) losses from the urea fertilizer can contribute to increasing its use efficiency in forage grasses. This study aimed to evaluate the effects of N sources and doses on the growth of Urochloa ruziziensis. The experiment was carried out in the growing season of 2007/2008 in Santo Antônio de Goiás-GO, in a Brazilian Oxisol. A completely randomized block was used, with four replicates in a factorial scheme, corresponding to two N sources (conventional urea and urea with urease inhibitor) and five N doses (0, 50, 100, 200 and 300 kg ha-1), divided into equal applications in five periods (Nov 14 to Dec 13, Dec 14 to Jan 12, Jan 13 to Feb 11 - rainy season, Mar 24 to Apr 22 and Jul 10 to Aug 08 - dry season). The effects of the treatments were evaluated for: shoot dry matter, tiller density, total N content in the leaves and relative chlorophyll content. N fertilizer sources did not affect the evaluated variables; however, N fertilization allowed linear increases in all variables with higher values during the rainy period. The relative chlorophyll content in U. ruziziensis had positive correlation with its dry matter productivity.

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