An empirical model for quantification of symbiotic nitrogen fixation in grass-clover mixtures

Høgh‐Jensen, Henning; Loges, Ralf; Jørgensen, Finn Vanman; Vinther, F.P.; Jensen, Erik Steen

doi:10.1016/j.agsy.2003.12.003

Cited by 132 publications

(77 citation statements)

References 46 publications

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“…Records of biological N fixation where legumes were present (using an empirical approach; Hogh-Jensen et al, 2004), N deposition (EMEP, 2012), and N removal by crops were also reported for each site. Annual N 2 O emissions were estimated cumulatively by linear interpolation between individual events.…”

Section: Methodsmentioning

confidence: 99%

Nitrous oxide emissions from European agriculture – an analysis of variability and drivers of emissions from field experiments

Augustin²,

et al. 2013

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Abstract. Nitrous oxide emissions from a network of agricultural experiments in Europe were used to explore the relative importance of site and management controls of emissions. At each site, a selection of management interventions were compared within replicated experimental designs in plot-based experiments. Arable experiments were conducted at Beano in Italy, El Encin in Spain, Foulum in Denmark, Logården in Sweden, Maulde in Belgium, Paulinenaue in Germany, and Tulloch in the UK. Grassland experiments were conducted at Crichton, Nafferton and Peaknaze in the UK, Gödöllö in Hungary, Rzecin in Poland, Zarnekow in Germany and Theix in France. Nitrous oxide emissions were measured at each site over a period of at least two years using static chambers. Emissions varied widely between sites and as a result of manipulation treatments. Average site emissions (throughout the study period) varied between 0.04 and 21.21 kg N2O-N ha−1 yr−1, with the largest fluxes and variability associated with the grassland sites. Total nitrogen addition was found to be the single most important determinant of emissions, accounting for 15% of the variance (using linear regression) in the data from the arable sites (p < 0.0001), and 77% in the grassland sites. The annual emissions from arable sites were significantly greater than those that would be predicted by IPCC default emission factors. Variability of N2O emissions within sites that occurred as a result of manipulation treatments was greater than that resulting from site-to-site and year-to-year variation, highlighting the importance of management interventions in contributing to greenhouse gas mitigation.

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Section: Methodsmentioning

confidence: 99%

Nitrous oxide emissions from European agriculture – an analysis of variability and drivers of emissions from field experiments

Augustin²,

et al. 2013

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“…1B) was defined as fertilizer-nitrogen supply plus an estimate of biologically fixed nitrogen (N bf ). The average N bf input for the spring growth was estimated using the model of Høgh-Jensen et al (2004) with the parameterization for cuts of 1-to 2 year-old mixed grass and red clover (Trifolium pratense) systems as described by Köhler et al (2012). Estimates of N bf were included for treatments with an average nitrogen fixation of greater than 10 kg ha 21 a 21 , which included treatments PK.L, PK.U, N*1.PK.L, and N*1.PK.U (Table I; Fig.…”

Section: Fertilizer and Liming Treatmentsmentioning

confidence: 99%

Last-Century Increases in Intrinsic Water-Use Efficiency of Grassland Communities Have Occurred over a Wide Range of Vegetation Composition, Nutrient Inputs, and Soil pH

2015

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Last-century climate change has led to variable increases of the intrinsic water-use efficiency (W i ; the ratio of net CO 2 assimilation to stomatal conductance for water vapor) of trees and C 3 grassland ecosystems, but the causes of the variability are not well understood. Here, we address putative drivers underlying variable W i responses in a wide range of grassland communities. W i was estimated from carbon isotope discrimination in archived herbage samples from 16 contrasting fertilizer treatments in the Park Grass Experiment, Rothamsted, England, for the 1915 to 1929 and 1995 to 2009 periods. Changes in W i were analyzed in relation to nitrogen input, soil pH, species richness, and functional group composition. Treatments included liming as well as phosphorus and potassium additions with or without ammonium or nitrate fertilizer applications at three levels. W i increased between 11% and 25% (P , 0.001) in the different treatments between the two periods. None of the fertilizers had a direct effect on the change of W i (DW i ). However, soil pH (P , 0.05), species richness (P , 0.01), and percentage grass content (P , 0.01) were significantly related to DW i . Grass-dominated, species-poor plots on acidic soils showed the largest DW i (+14.7 mmol mol 21 ). The DW i response of these acidic plots was probably related to drought effects resulting from aluminum toxicity on root growth. Our results from the Park Grass Experiment show that W i in grassland communities consistently increased over a wide range of nutrient inputs, soil pH, and plant community compositions during the last century.

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“…Its quantity varies with the surface cultivated with legume crops and the plant species. The N-fixation coefficients was estimated through the model proposed by Høgh-Jensen et al (2004), which also considers the amount of N accumulated belowground and allow a locality-specific parametrization of user defined parameters. The model adapted to our condition is the following: NSF = DMlegume * N% * Pfix * (1+Prott+stubble + Pimmobile) where DMlegume = accumulated amount of legume shoot dry matter; N% = concentration of N in the dry matter of the legume (kg kg -1 ); Pfix = fixed N2 as proportion of total N in the shoot dry matter of the legume; Proot+stubble = fixed N2 in the root and stubble as proportion of totally fixed shoot N at the end of the growing period; Pimmobile = fixed N2 immobilised in an organic soil pool at the end of the growing period as proportion of fixed shoot N at the end of the growing period.…”

Section: Agricultural Biological Nitrogen Fixationmentioning

confidence: 99%

Nitrogen balance in a hilly semi-agricultural watershed in Northern Italy

et al. 2011

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The research was carried out for 7 years, 1998-2005, in a semi-agricultural watershed, called Centonara, set within a natural regional park and situated in the hills surrounding Bologna, northern Italy. This area is characterized by one of the most interesting badlands complexes in Europe and represents one of the main points of naturalistic interest. The watershed is partially cultivated (about 30% of the total area) with arable crops, mostly cereals and alfalfa. To evaluate the impact of agricultural activity on the eco-sustainability of this area, the nitrogen (N) balance was computed. Although it is only an estimation of the potential environmental damage, the nitrogen balance is a useful indicator of the risk posed to the environment from excessive nitrogen and can be useful to understand the possible effects of a certain type of agricultural and environmental management and policy. The balance was calculated by computing the difference between all inputs and all outputs. The nitrogen balance of the watershed was found to be sustainable, with an annual nitrogen balance ranging between -2.3 and +4.4 kg ha -1 . Despite the limited presence of arable lands, the agricultural management played the main role in determining the sustainability of the watershed, strongly influencing both the principal N sources and sinks. In fact, major N inputs derived from inorganic fertilization (8.1-15.5 kg ha -1 yr -1 ) and biological fixation (8.3-14.3 kg ha -1 yr -1 ). On the other hand, plant removal constituted the most important output (17.7-25.6 kg ha -1 yr -1 ). N losses in the drainage water were limited (3.0-9.5 kg ha -1 yr -1 ) and the Centonara stream water was found to be unpolluted, with a nitrate concentration always below the EU limit for drinking water. The similar magnitude of total N inputs and outputs indicated that the crop management, especially the crop rotation and the N fertilization, in the Centonara watershed has reached a good level of ecological sustainability. Finally, the computation of the N fertilizer-use efficiency index resulted to be useful to identify which crop and which type of management (organic or conventional) were more suitable for the pedo-climatic condition of the studied area.

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An empirical model for quantification of symbiotic nitrogen fixation in grass-clover mixtures

Cited by 132 publications

References 46 publications

Nitrous oxide emissions from European agriculture – an analysis of variability and drivers of emissions from field experiments

Nitrous oxide emissions from European agriculture – an analysis of variability and drivers of emissions from field experiments

Last-Century Increases in Intrinsic Water-Use Efficiency of Grassland Communities Have Occurred over a Wide Range of Vegetation Composition, Nutrient Inputs, and Soil pH

Nitrogen balance in a hilly semi-agricultural watershed in Northern Italy

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