Nitrous oxide emissions from fertilized and unfertilized grasslands on peat soil

Emissions of nitrous oxide (N2O) from managed and grazed grasslands on peat soils are amongst the highest emissions in the world per unit of surface of agriculturally managed soil. According to the IPCC methodology, the direct N2O emissions from managed organic soils is the sum of N2O emissions derived from N input, including fertilizers, urine and dung of grazing cattle, and a constant ‘background’ N2O emission from decomposition of organic matter that depends on agro-climatic zone. In this paper we questioned the constant nature of this background emission from peat soils by monitoring N2O emissions, groundwater levels, N inputs and soil NO3 -–N contents from 4 grazed and fertilized grassland fields on managed organic peat soil. Two fields had a relatively low groundwater level (‘dry’ fields) and two fields had a relatively high groundwater level (‘wet’ fields). To measure the background N2O emission, unfertilized sub-plots were installed in each field. Measurements were performed monthly and after selected management events for 2 years (2008–2009). On the managed fields average cumulative emission equaled 21 ± 2 kg N ha-1y-1 for the ‘dry’ fields and 14 ± 3 kg N ha-1y-1 for the ‘wet’ fields. On the unfertilized sub-plots emissions equaled 4 ± 0.6 kg N ha-1y-1 for the ‘dry’ fields and 1 ± 0.7 kg N ha-1y-1 for the ‘wet’ fields, which is below the currently used estimates. Background emissions were closely correlated with groundwater level (R 2 = 0.73) and accounted for approximately 22% of the cumulative N2O emission for the dry fields and for approximately 10% of the cumulative N2O emissions from the wet fields. The results of this study demonstrate that the accuracy of estimating direct N2O emissions from peat soils can be improved by approximately 20% by applying a background emission of N2O that depends on annual average groundwater level rather than applying a constant valu

Nitrous oxide emissions from multiple combined applications of fertiliser and cattle slurry to grassland

Fertiliser and manure application are important sources of nitrous oxide (N2O) emissions from agricultural soils. The current default IPCC emission factor of 1.0% is independent of the type of fertiliser and manure, and application time, method and rate. However, in the IPCC Tiered system it is possible to use more specific emission factors that better reflect the actual fertiliser and manure management in a given country or region. The first and primary aim of this study was to determine whether the combination of cattle slurry injection with fertiliser application, which is common practice in intensively managed grasslands in the Netherlands and neighbouring countries, warrants an adjusted emission factor. A second aim was to evaluate whether alternative emission factors, based on N uptake and N surplus, respectively, give more insight in the N2O emission rates of various fertilisation strategies. In a 2-year field experiment on sandy soil in the Netherlands we measured the annual N2O emission from grasslands receiving repeated simultaneous applications of fertiliser and cattle slurry. The N2O fluxes and N uptake by grass were measured from plots receiving calcium ammonium nitrate (CAN) at four application rates, either with or without additional application of liquid cattle slurry, applied through shallow soil injection. The average emission factor for fertiliser-only treatments was 0.15%. The annual N2O emissions were similar for treatments receiving only fertiliser or only cattle slurry. In the first experimental year, application of cattle slurry increased the emission factor for fertiliser to 0.35%, but the second year showed no effect of cattle slurry on the emission from fertiliser. With regard to the first objective, we conclude that these results do not conclusively justify an adjusted emission factor for combined application of fertiliser and cattle slurry. To minimise risks however, it is sensible to avoid simultaneous application of fertiliser and cattle slurry. The N2O emission factor expressed as percentage of kg N uptake by grass was consistently higher after combined application of fertiliser and cattle slurry (0.29%), compared to fertiliser-only (0.17%). With regard to the second objective we conclude that an emission factor based on N uptake expresses the relatively inefficient N supply of cattle slurry to crop growth better than the traditional emission factor based on N application

Klimaat en veehouderij : inzichten vanuit het onderzoek van Wageningen UR, mede naar aanleiding van de film "Meat the truth"

Nederland heeft zich (in het kader van het Kyoto protocol) verplicht om de uitstoot van broeikasgassen te verminderen ten opzichte van het referentiejaar 1990. Wat betreft de veehouderij sector heeft de film 'Meat the Truth' van de Partij voor de Dieren (PvdD) het vraagstuk eind 2007 op de agenda geplaatst. In die film wordt de relatie tussen veehouderij en klimaat behandeld. De feitelijke basis voor de film wordt vooral gevormd door het rapport Livestock's Long Shadow (Steinfeld, FAO, 2006

Klimaatverandering, klimaatadaptatie en bodem: maakbaarheid, planvorming en realiteitsdenken

Dit rapport presenteert een beknopt overzicht van de stand van zaken (state-of-the-art) in het nationale en internationale onderzoek naar de relatie van klimaatverandering en bodem en van de mogelijkheden om de bodem te gebruiken voor slimme en effectieve adaptatie aan klimaatverandering in Nederland. De analyse is gericht op alle typen bodems die in Nederland voorkomen en omvat zowel natuurlijke en kunstmatig gevormde bodems, bodems in en onder bebouwd gebied en (onder)waterbodem

The Kyoto Article 3.3 and 3.4 toolbox (KAT); January 2000

The KAT model provides a spreadsheet-based framework to calculate carbon sequestration in the commitment period (2008-2012) under Article 3.3 and 3.4 activities of the Kyoto protocol for the EU15 countries and selected Annex 1 countries. Any combination of 3.3 scenarios, 3.4 activities and sub-rules on Articles 3.3 and 3.4 based on policy proposals can be chosen. The carbon sequestration is calculated and presented in graphs and tables both in absolute values and in percentages of the1990 emissions. The user can interactively choose between a literature database and a database that consists of data submitted by countries under the UNFCC regulations

Method and timing of grassland renovation affects herbage yield, nitrate leaching, and nitrous oxide emission in intensively managed grasslands

Managed grasslands are occasionally ploughed up and reseeded in order to maintain or increase the sward productivity. It has been reported that this renovation of grassland is associated with a flush of soil organic nitrogen (N) mineralization and with a temporary increase in soil mineral N contents. Here, we report on the effects of method and time of grassland renovation on herbage yield, nitrate (NO3 -) leaching and nitrous oxide (N2O) emission. Field experiments were carried out at three sites (two sandy soils and a clay soil) in the Netherlands for three years. Renovation of grassland increased the percentage of Perennial ryegrass from 48–70% up to more than 90%. However, averaged over three years, dry matter yields were higher for the reference (not reseeded) swards (on average 13.6 Mg ha-1 for the highest N application rate) than for the renovated grasslands (12.2–13.1 Mg ha-1 dry matter). Grassland renovation in April did not increase N leaching in comparison to the reference. However, renovation in September increased the risk of leaching, because mineral N contents in the 0–90 cm were in November on average 46–77 kg N ha-1 higher than in the reference. Contents of dissolved organic N (DON) in the soil were not affected by renovation. Renovation increased N2O emissions by a factor of 1.8–3.0 relative to the reference grassland. Emissions of N2O were on average higher after renovation in April (8.2 kg N2O-N ha-1) than in September (5.8 kg N2O-N ha-1). Renovation without ploughing (i.e. only chemically destruction of the sward) resulted in a lower percentage of perennial ryegrass (60–84%) than with ploughing (>90%). Moreover, N2O emissions were higher after renovation without ploughing than with ploughing. Clearly, farmers need better recommendations and tools for determining when grassland renovation has beneficial agronomic effects. Losses of N via leaching and N2O emission after renovation can probably not be avoided, but renovation in spring in stead of autumn in combination with ploughing and proper timing of fertilizer application can minimize N losses

LULUCF values under the Kyoto Protocol : background document in preparation of the National Inventory Report 2011 (reporting year 2009)

This report collects all background information that is used for the 2011 submission under the Kyoto Protocol (KP) for the Netherlands. It includes the full text of the National Inventory Report (NIR)-II for LULUCF, as well as a description of the table-bytable methodologies, choices and motivations. In 2009 afforestation and reforestation activities produced a sink of 546.68 Gg CO2 equivalents while deforestation caused an emission of 780,45 Gg CO2 equivalents. These values were based on changes in above- and belowground biomass, dead wood, litter and soil (mineral as well as organic), and agricultural lime application on deforested areas. The values for 2008 were recalculated from last year, and the recalculation included changes due to: (i) This was the first year emissions from mineral and organic soils were reported for Afforestation, Reforestation, and Deforestation (ARD). (ii) An error in harvested wood was corrected, and (iii) The calculation of dead wood was improved. Some minor gaps remain to be solved in the coming year(s), especially for the estimation of uncertainty of all reported values

Beperking van emissie van methaan en lachgas uit de landbouw: identificatie van kennishiaten

In dit rapport worden kennishiaten geïdentificeerd en advies gegeven over hoe deze via vervolgonderzoek weg te werken. Hierbij is gebruik gemaakt van ervaringen in literatuuronderzoek en recente projecten en met name de ROB-AGRO-projecten. Er zijn rond acht thema’s belangrijke kennishiaten gesignaleerd: 1 Aanpak van emissiebeperking in omringende landen 2 Variaties in de praktijk in emissies en ontwerp en analyse van strategieën voor implementatie van emissiebeperkende maatregelen in de praktijk 3 Kwantificering en vermindering van indirecte lachgasemissies uit de landbouw 4 Emissie van methaan uit mestopslagen 5 Emissies van lachgas na toediening van dierlijke mest aan maïs- en bouwland 6 Effecten van grondsoort en waterbeheer op emissies van lachgas en methaan 7 Analyse van onzekerheden in emissiebeperkende maatregelen en monitoring en toetsing van de effectiviteit van emissiebeperkende maatregelen in de praktijk 8 Interacties tussen veevoeding, beweiding en grondsoort op emissies van methaan uit herkauwers en mestopslagen en lachgas uit de bodem

Organische stof: onbemind of onbekend?

Deze studie inventariseert recente inzichten over organische stof in de bodem en inventariseert kennisvragen en -leemtes. De aandacht gaat uit naar mogelijke veranderingen en verlies van organische stof, daarmee samenhangende risico's , mogelijke reacties en waarnemingen van effecten van handelen. Een studie in opdracht van MPB Bilthove