4.B Manure Management

Last updated on 10 Dec 2013 11:53 (cf. Authors)

NFR-Code Name of Category Method AD EF Key Source for (by)
4.B Manure Management
consisting of / including source categories
4.B 1a & 1b Cattle T3 (NH3), T2 (NOx), T1 (TSP, PM) NS, RS CS (NH3, NOx), D (PM) NH3 (L/T)
4.B 3, 4, 5, 6, 7 Buffalo, Sheep, Goats, Horses, Mules and Asses T2 (NH3), T1 (NH3, NOx, PM) NS CS (NH3,NOx), D (PM) -
4.B 8 Swine T3 (NH3), T2 (NOx), T1 (TSP, PM) NS, RS CS (NH3, NOx), D (PM) NH3 (L/T), TSP (L), PM10 (L)
4.B 9a, 9b, 9c, 9d Poultry T2 (NH3, NOx), T1 (PM) NS, RS CS (NH3, NOx), D (PM) NH3 (T)
Kuhstall.png

Country specifics

In 2011, NH3 emissions from the agricultural sector derived up to 83.7% from sector 4.B (manure management), which is equal to ~443 Gg NH3. Within those emissions 62% originate from cattle manure (~275 Gg), 24% from pig manure (ca.107 Gg), and 11% from poultry manure (~49 Gg). The modelling of anaerobic digestion of slurry has been newly implemented in the inventory model for the present submission. Its impact on the emission calculations yields a total reduction of NH3 emissions from animal husbandry of about 2.5 Gg in 2011. The reduction effect is mainly caused by a relatively high frequency of gastight storage of digested slurry. For details see Rösemann et al. (2013) [12].

NOx emissions from sector 4.B contribute only 1.9% (~1.7 Gg) to the total agricultural NOx emissions. The NOx emissions are also affected by the introduction of anaerobic digestion of slurry into the inventory modelling. In 2011 they are about 0.1 Gg lower than they would have been without anaerobic digestion This percentage is estimated from digestion-induced N2O reductions, see Rösemann et al. (2013) [12]), as NOx is calculated proportionally to N2O.

NMVOC emissions from Agriculture are not reported since Submission 2012 as the methodology used in previous submissions has been evaluated as not adequate by international experts (see Rösemann et al., 2013 [12]).

Activity data for all pollutants

The Federal Statistical Agency and the Statistical Agencies of the federal states carry out agricultural-structure surveys in order to collect, along with other data, the head counts of cattle, pigs, sheep, horses (from 2010 onwards: equids) and poultry.
These agricultural-structure surveys took place every other year for the years 1990 – 1996 and 1999 – 2007 as well as for 2010 in the context of the more comprehensive 2010 agricultural census (Landwirtschaftszählung 2010, LZ 2010). The surveys 1990, 1994 and 1996 referenced to the 3. December, while the surveys 1999 – 2007 referenced to 3. May. The LZ 2010 referenced to 1. March.

In addition to the agricultural-structure surveys, annual animal head count censuses are carried out by the Federal Statistical Agency. Up to and including 1998 these censuses took place every six months for cattle and sheep (June, December), every four months for pigs (April, August, December), and in even years in December for all animal categories, i. e. also for horses and poultry. Reference day was always the third day of the respective month. Since 1999 the animal head count censuses take place two times a year: 3. May and 3. November for cattle and pigs, 3. May for sheep (3. November from 2011 onwards).

For cattle, pigs, and sheep official animal numbers are available for all years since 1990. This means that the inventories up to and including 1998 used the data collected in December (in June for sheep), while afterwards the inventories up to and including 2010 used the data from May. According to the Federal Statistical Agency the animal numbers for the inventories from 2011 onwards have to be referenced to November. For horses (or equids) as well as poultry, animal numbers are available only every other year (referenced to 3 December for data up to and including 1998, referenced to 3 March for 1999 to 2007, referenced to 1 March in 2010, and referenced to 3 November in 2011.) in accordance with the Federal Statistical Agency animal numbers are not corrected for the varying reference dates.

As part of the agricultural census in 2010 the total number of equids has been collected officially for the first time, not differentiating between horses and mules and asses. This number is interpreted as the total number of horses, as it is not possible to adequately define and subtract the number of mules and asses. However, the error caused by this simplification is negligible due to the small number of mules and asses: About 6,000 to 8,000 asses and about 500 mules and hinnies were kept in Germany in 2003 (Deutsches Eselstammbuch, 2003). No time series is available for the years 1990 – 2010. Hence, the inventory assumes a constant number of 8,500 asses and mules.

The number of goats has not been recorded in agricultural statistics between 1977 und 2010. For the years 1990 - 2004, the Federal Ministry of Food, Agriculture and Consumer Protection (BMELV) estimated the goat population on national level. For the years 2005 – 2009 the national total of goats was estimated by the Federal Statistical Office. In 2010 goats were counted as part of the agricultural census 2010. This 2010 number, used also for 2011, is significantly smaller than the estimated numbers of the previous years. The latter, however, are not corrected but maintained in agreement with the Federal Statistical Office.

German agricultural statistics do not include herd-size figures for buffalo. The relevant figures for buffalo are provided by Deutscher Büffel-Verband (the German Buffalo Association) for the years as of 2000. In keeping with a recommendation in the final report for the "Initial Review under the Kyoto Protocol and Annual 2006 Review under the Convention", the time series for the buffalo population was completed for the years prior to 2000. This was accomplished via linear extrapolation. In this process, arithmetically negative animal populations resulted for the years 1990 to 1995 and were replaced with "zeros".

The inventory calculations require the definition of animal categories as homogeneous as possible with respect to feeding and husbandry details. Some of the animal categories defined within the official statistical censuses do not meet these requirements. Hence, their animal numbers have to be regrouped in order to fit the animal categories used in the inventory. This is why the herd-size numbers used in the inventory for calves, heifers, fattening bulls, weaners, fattening pigs, laying hens and pullets differ from the respective numbers in the official statistics (see Rösemann et al., 2013 [12]).

However, the total for all cattle, the sum of the figures for pullets and laying hens, and the sum of the figures for turkey roosters and turkey hens are each in accordance with the official statistics.
Since 2008 the animal surveys by the Federal Statistical Agency do not longer distinguish between the cattle categories “suckler cows” and “female cattle for slaughtering” but count these animals as “other cows”. Up to and including Submission 2012 “female cattle for slaughtering” were considered part of the inventory category “heifers” while the “suckler cows” formed a separate category. In order to obtain a consistent time series since 1990 for all inventories following Submission 2012, “female cattle for slaughtering” are considered to be part of the inventory category “suckler cows” from 1990 onwards. Hence the category “other cows” introduced by the Federal Statistical Agency corresponds to the inventory category “suckler cows”.

In order to obtain homogeneous pig categories for the inventory, some of the pig categories used in the official survey have been modified. Based on the approach described in Haenel et al. (2011) [1], the official animal numbers for piglets up to a weight of 20 kg per animal and for “young pigs and fattening pigs” above 20 kg per animal are transformed into animal numbers for the inventory categories “weaners” and “fattening pigs”. This transformation has no impact on the total number of pigs in the emission inventory. However, the total number of pigs in the emission inventory is lower than the total number of pigs officially counted. This is due to the fact that those piglets officially counted with a weight lower than 8 kg per animal are considered sucking pigs, which, with respect to emissions, do not form a separate animal category in the inventory but are part of the system “sows and sucking pigs”.

After the German reunification animal livestock decreased in 1991. The animal population figures the actual inventory is based on are presented in the table 1. The head counts for cattle, swine, horses, sheep and goats decreased between 2005 and 2010 while in 2011 the number of dairy cattle and pigs slightly increased. The total poultry population strongly increased since 2005 due to higher numbers of broilers, turkeys and ducks in 2011. Data for each animal category for the whole time series from 1990 until 2011 can be found in the National Inventory Report (NIR 2013 [11]) in Table 144.

Table 1: Population of animals

Population of animals
1990 1995 2000 2005 2010 2011
dairy cattle 6,354,555 5,229,227 4,569,752 4,236,394 4,183,111 4,190,103
other cattle 13,133,442 10,661,219 9,968,306 8,799,220 8,626,381 8,337,737
buffalo NO NO 626 1,187 2,362 2,680
mules and asses 8,500 8,500 8,500 8,500 8,500 8,500
horses 490,954 625,649 491,036 499,886 461,779 461,779
sheep 3,266,100 2,990,670 2,743,276 2,643,125 2,088,541 1,660,118
swine 26,502,466 20,387,251 21,767,746 22,742,803 22,244,381 22,787,816
laying hens 53,450,546 45,317,296 44,225,649 38,203,868 35,314,174 35,314,174
broilers 35,393,005 42,025,817 50,359,931 56,762,637 67,428,196 70,556,286
turkeys 5,029,160 6,742,043 8,893,086 10,611,031 11,343,962 11,494,577
pullets 17,210,833 14,591,964 14,240,459 12,301,472 11,371,004 11,371,004
ducks 2,013,655 1,933,719 2,055,688 2,352,290 3,164,334 3,346,457
geese 781,487 617,032 404,752 329,677 278,080 261,647
goats 90,000 100,000 140,000 170,000 149,936 149,936

Additional data

To calculate emissions in accordance with a Tier-2 or Tier 3 method, data on animal performance (animal weight, weight gain, milk yield, milk protein content, milk fat content, numbers of births, numbers of eggs and weights of eggs) and on the relevant feeding details (phase feeding, feed components, protein and energy content, digestibility and feed efficiency) are required. To divide officially recorded total numbers of turkeys into roosters and hens, one must know the applicable sex ratio.
For the most part, such data is not available from official statistics and was obtained from the open literature, from association publications, from regulations for agricultural consulting in Germany and from expert judgments.
Up to 1999, frequency distributions of feeding strategies, husbandry systems (shares of pasturing/stabling; shares for various housing methods), storage types as well as techniques of farm manure spreading were obtained with the help of the RAUMIS agricultural sector model (Regionalisiertes Agrar- und UmweltInformationsSystem für Deutschland; Regionalised agricultural and environmental information system for Germany). RAUMIS has been developed and is operated by the Institute of Rural Studies of the Thünen Institute (Federal Research Institute for Rural Areas, Forestry and Fisheries). For an introduction to RAUMIS see WEINGARTEN (1995 [6]); a detailed description is provided in HENRICHSMEYER et al. (1996 [7]).

An update of the RAUMIS data was not possible before 2010 when the results of the 2010 official agricultural census and the simultaneous survey of agricultural production methods (Landwirtschaftliche Zählung 2010, Statistisches Bundesamt) as well as the 2011 survey on manure application practices (Erhebung über Wirtschaftsdüngerausbringung, Statistisches Bundesamt) became available. For details see Rösemann et al. (2013) [12].
The gaps between the latest RAUMIS data (1999) and the new 2010/2011 data were closed by linear interpolation on district level. For 2011 data it was assumed that the 2010 data could be kept.

Table 2 presents mean animal weights for dairy cows, other cattle, swine and poultry. Data for the entire time series 1990-2011 can be found in the National Inventory Report (NIR 2013 [11]) in Table 145. For the Tier-1 based emission calculations of sheep, goats, horses, asses and mules and buffalo no weight data are needed.

Table 2: Mean animal weights

Mean animal weights in kg/animal
1990 1995 2000 2005 2010 2011
Dairy cows 607.9 621.8 644.3 645.8 646.8 648.0
Other cattle 300.1 313.7 329.5 326.4 330.0 327.2
Swine 72.8 74.1 72.4 72.4 70.5 69.0
Poultry 1.77 1.71 1.80 2.01 1.96 1.97

NH3 & NOx

Methodology

N in manure management

N excretion

In order to determine NH3 and NOx emissions from manure management of a specific animal category the individual N excretion rate must be known. While default exrection rates are provided by IPCC Guidelines, the German agricultural emission inventory uses N mass balances to calculate the N excretions of almost all animal categories to be reported. The calculation of N excretion with the help of a N mass balance considers N intake with feed, N retention due to growth, N seceded with milk & eggs, and N in the offspring produced. For more details see Rösemann et. al. (2013) [12].

N mass flow and emission assessment for mammals

The calculation of the emissions of NH3, N2O, NOx and N2 from German animal husbandry is based on the so-called N mass flow approach. This method reconciles the requirements of both the Atmospheric Emission Inventory Guidebook for NH3 emissions and the IPCC guidelines for greenhouse gas emissions (Dämmgen and Hutchings (2008) [3]). According to the N mass flow approach the N flow within the manure management system is treated as depicted in the figure below. In Europe, this approach is also applied in Denmark, the United Kingdom, the Netherlands and Switzerland. In spite of national peculiarities, a comparison of the national solutions showed identical results as long as standardised data sets for the input variables were used (Reidy et al. (2008) [2]).The approach differentiates between N excreted with faeces and urine and two fractions of N

  • Norg: organic nitrogen is the fraction that is undigested N in the feed and exreted with faeces;
  • TAN (total ammoniacal nitrogen) is the fraction of N that was metabolised and is excreted with urine.
N_flow_model.jpg
N flows in an animal subcategory. Mammals

m: mass from which emissions may occur. Narrow broken arrows: TAN (total ammonical nitrogen); narrow continuous arrows: organic N. The horizontal arrows denote the process of immobilisation in systems with bedding occurring in the house, and the process of mineralisation during storage, which occurs in any case. Broad hatched arrows denote emissions assigned to manure management: E emissions of N species (Eyard NH3 emissions from yards; Ehouse NH3 emissions from house; Estorage NH3, N2O, NOx and N2 emissions from storage; Eapplic NH3 emissions during and after spreading. Broad open arrows mark emissions from soils: Egraz NH3, N2O, NOx and N2 emissions during and after grazing; Ereturned N2O, NOx and N2 emissions from soil resulting from manure input.

The figure allows tracing of the pathways of the two N fractions after excretion. The various locations where excretion may take place are considered. The partial mass flows down to the input to soil are depicted. During storage both fractions, Norg and TAN, react to form the respective other fraction. Both the way and the amount of such transformations may be influenced by manure treatment processes.
Whenever NH3 is emitted, the formation is related to the amount of the reactive TAN fraction. NOx emissions (i. e. NO emissions) are calculated proportionally to the N2O emissions. The latter are related to the total amount of N available (Norg + TAN).

Note that the N2O, NOx and N2 emissions from the various storage systems include the respective emissions from the related housing systems.

N mass flow model for birds

Birds excrete N in the form of undigested organic N and in uric acid (uric acid nitrogen, UAN). The latter is hydrolised to form ammonium carbonate (see Dämmgen and Erisman (2005) [5]). Thus, in principle, three fractions of N have to be traced, as shown in the figure below.

N_flow_model_birds.jpg

N flows in an animal subcategory. Birds.

m: mass from which emissions may occur. Narrow broken arrows: TAN; narrow broken and dotted line: UAN; narrow continuous arrows: organic N. The horizontal arrows denote the process of immobilisation in systems with bedding occurring in the house, and the process of mineralisation during storage, which occurs in any case. Broad hatched arrows denote emissions assigned to manure management: E emissions of N species (Eyard NH3 emissions from yards; Ehouse NH3 emissions from house; Estorage NH3, N2O, NOx and N2 emissions from storage; Eapplic NH3 emissions during and after spreading. Broad open arrows mark emissions from soils: Egraz NH3, N2O, NOx and N2 emissions during and after grazing; Ereturned N2O, NOx and N2 emissions from soil resulting from manure input.

At present, a similar treatment of TAN as applied for mammals is impossible for birds, as the hydrolysis of uric acid producing ammonium carbonate occurs outside the birds’ bodies. In particular, it is difficult to model the influence of humidity on this process.
Hence, the inventory assumes that UAN excreted can completely be considered TAN.

Anaerobic digestion of slurry

The inventory calculates NH3 emissions from the management of the residues of anaerobic slurry digestion, i. e. from storage and spreading. It is assumed that no emissions occur from the digester. Consistently with the calculation of CH4 emissions according to IPCC (1996) [8] (for details see Rösemann et al., 2013, [12]),), the calculation of NH3 emissions considers two different types of residue storage, i. e. gastight storage and open tanks.
In the inventory, the spreading of residues is treated separately from the spreading of untreated slurry as the frequencies of spreading techniques and durations of incorporation are different for untreated and digested slurry (for the frequency data see Rösemann et al., 2013, [12]).

Emission Factors

Application of the N mass flow approach requires detailed emission factors for NH3, N2O, NOx and N2 describing the emissions from the various housing and storage systems as well as the various manure application techniques.
In general, the detailed NH3, emission factors are related to the amount of TAN available at the various stages of the N flow. These NH3, emission factors are mainly country specific but are also taken from EMEP (2009) [10]. As no specific NH3 emission factors are known for the application of digested slurry, the emission factors for untreated slurry were adopted.

The detailed emission factors for N2O, NOx and N2 relate to the amount of N available which is N excreted plus (in case of solid manure systems) N input with bedding material. The N2O, emission factors are taken from IPCC (2006) [4] while the emission factors for NOx and N2 are approximated as proportional to the N2O emission factors. This proportionality is also applied to anaerobic digestion of slurry, where the N2O emission factor is provided by IPCC (1996) [8]. Note that the inventory model calculates NO rather than NOx. The NO emissions are then converted to NOx emissions by multiplying with 46/30 which means a transformation into NO2. Equivalently, this conversion can also be applied to the emission factors as is shown in Table 3.

For a detailed description of the emission factors see Rösemann et al. (2013) [12].

Another type of emission factor is the implied emission factor (IEF) which can be obtained from the N mass flow approach. The implied emission factor is defined as the ratio of the total emission from an animal category to the respective number of animals. Table 3 shows the implied emission factors of NH3 and NOx for the various animal categories

Table 3: IEF for NH3 & NOx

Implied emission factors for NH3 & NOx
1990 1995 2000 2005 2010 2011
animal NH3 in kg/animal place
dairy cattle 30.66 33.22 34.52 35.62 35.80 35.92
other cattle 15.41 14.95 15.12 15.16 14.92 14.88
buffalo NO NO 29.47 29.47 29.47 29.47
mules and asses 13.06 13.06 13.06 13.06 13.06 13.06
horses 18.91 18.88 19.23 19.18 19.14 19.14
sheep 1.62 1.62 1.64 1.64 1.69 1.74
swine 5.64 5.45 5.40 5.22 4.81 4.69
laying hens 0.45 0.44 0.41 0.44 0.43 0.43
broilers 0.23 0.19 0.22 0.23 0.25 0.26
turkeys 1.03 1.03 1.03 1.14 1.10 1.10
pullets 0.18 0.16 0.15 0.16 0.15 0.15
ducks 0.26 0.26 0.26 0.26 0.26 0.26
geese 0.38 0.38 0.38 0.38 0.38 0.38
goats 3.02 3.02 3.02 3.02 3.02 3.02
NOx converted in kg NO2/animal place
dairy cattle 0.17 0.16 0.16 0.17 0.16 0.16
other cattle 0.075 0.079 0.081 0.085 0.089 0.089
buffalo NO NO 0.20 0.20 0.20 0.20
mules and asses 0.14 0.14 0.14 0.14 0.14 0.14
horses 0.20 0.20 0.20 0.20 0.20 0.20
sheep 0.018 0.018 0.018 0.018 0.018 0.019
swine 0.015 0.015 0.015 0.016 0.016 0.015
laying hens 0.00026 0.00026 0.00024 0.00027 0.00027 0.00028
broilers 0.00016 0.00014 0.00017 0.00018 0.00020 0.00021
turkeys 0.00059 0.00059 0.00060 0.00066 0.00065 0.00065
pullets 0.00012 0.00010 0.00010 0.00010 0.00010 0.00010
ducks 0.00017 0.00017 0.00017 0.00017 0.00017 0.00017
geese 0.00018 0.00018 0.00018 0.00018 0.00018 0.00018
goats 0.033 0.033 0.033 0.033 0.033 0.033

NMVOCs

NMVOC emissions from agriculture are not reported as there is no adequate method (see Rösemann et al., (2013) [12]).

PM2,5 & PM10

In 2011, PM2,5 emissions from the agricultural sector derive up to 89.9 % from animal manure. Within those emissions 52.9 % originate from cattle manure, 25.3 % from pig manure, and 21.0 % from poultry manure.

In 2011, PM10 emissions from the agricultural sector derive up to 52.3 % from animal manure. Within those emissions 21.8 % originate from cattle manure, 41.1 % from pig manure, and 36.8 % from poultry manure.

Method

EMEP(2009)-4B-25[10]) provides a Tier 2 methodology to assess the emissions of PM10 and PM2,5 from animal housing which was adopted. However, EMEP(2009)-4B-30[10]) states that the emission factors are a first estimate only, thus the calculations in this inventory provide only a first estimate of particulate matter from animal husbandry.

Activity data

Please see table 1 top of page.

Emission factors

Tier 2 emission factors for PM10 and PM2,5 from animal housing are provided in EMEP(2009)-4B-27, Table 3-10 [10]). For cattle and swine these emission factors differentiate between slurry and solid manure systems. For buffalo, sheep and goats no PM emission factors are available.
The implied emission factors given in Table 5 relate the overall PM emissions to the number of animals in each animal category.

Table 5: IEF for PM2,5 & PM10

Implied emission factors for PM2,5 & PM10
1990 1995 2000 2005 2010 2011
animal PM10 in kg/animal place
dairy cattle 0.48 0.55 0.56 0.57 0.58 0.57
other cattle 0.25 0.25 0.25 0.24 0.24 0.24
buffalo NE NE NE NE NE NE
mules and asses 0.14 0.14 0.14 0.14 0.14 0.14
horses 0.14 0.14 0.14 0.14 0.14 0.14
sheep NE NE NE NE NE NE
swine 0.38 0.38 0.38 0.37 0.36 0.036
laying hens 0.021 0.021 0.026 0.035 0.072 0.075
broilers 0.052 0.052 0.052 0.052 0.052 0.052
turkeys 0.032 0.032 0.032 0.032 0.032 0.032
pullets 0.052 0.052 0.052 0.052 0.052 0.052
ducks 0.032 0.032 0.032 0.032 0.032 0.032
geese 0.032 0.032 0.032 0.032 0.032 0.032
goats NE NE NE NE NE NE
PM2,5 in kg/animal place
dairy cattle 0.31 0.36 0.36 0.37 0.37 0.37
other cattle 0.17 0.17 0.16 0.16 0.16 0.16
buffalo NE NE NE NE NE NE
mules and asses 0.10 0.10 0.10 0.10 0.10 0.10
horses 0.10 0.10 0.10 0.10 0.10 0.10
sheep NE NE NE NE NE NE
swine 0.062 0.062 0.062 0.061 0.060 0.060
laying hens 0.0028 0.0028 0.0038 0.0058 0.0135 0.0140
broilers 0.0070 0.0070 0.0070 0.0070 0.0070 0.0070
turkeys 0.0040 0.0040 0.0040 0.0040 0.0040 0.0040
pullets 0.0070 0.0070 0.0070 0.0070 0.0070 0.0070
ducks 0.0040 0.0040 0.0040 0.0040 0.0040 0.0040
geese 0.0040 0.0040 0.0040 0.0040 0.0040 0.0040
goats NE NE NE NE NE NE
Bibliography
1. Haenel H.-D., Dämmgen U., Rösemann C. (2011): Estimating numbers of piglets, weaners and fattening pigs for the German agricultural emission inventory. Landbauforsch 61(3), 229-236.
2. Reidy B., Dämmgen U., Döhler H., Eurich-Menden B., Hutchings N.J., Luesink H.H., Menzi H., Misselbrook T.H., Monteny G.-J., Webb J. (2008): Comparison of models used for the calculation of national NH3 emission inventories from agriculture: liquid manure systems. Atmospheric Environment 42, 3452-3467.
3. Dämmgen U., Hutchings N.J. (2008): Emissions of gaseous nitrogen species from manure management - a new approach. Environmental Pollution 154, 488-497.
5. Dämmgen U., Erisman J.W. (2005): Emission, transmission, deposition and environmental effects of ammonia from agricultural sources. In: Kuczyński T., Dämmgen U., Webb J., Myczko (eds) Emissions from European Agriculture. Wageningen Academic Publishers, Wageningen. pp 97-112.
6. Weingarten, P. (1995): Das „Regionalisierte Agrar- und Umweltinformationssystem für die Bundesrepublik Deutschland“ (RAUMIS). Ber Landwirtschaft 73, 272-302.
7. Henrichsmeyer, W.; Cypris, Ch.; Löhe, W.; Meuth, M.; Isermeyer F; Heinrich, I.; Schefski, A.; Neander, E.; Fasterding, F.;, Neumann, M.; Nieberg, H.( 1996): Entwicklung des gesamtdeutschen Agrarsektormodells RAUMIS96. Endbericht zum Kooperationsprojekt. Forschungsbericht für das BMELF (94 HS 021), Bonn, Braunschweig.
8. IPCC – Intergovernmental Panel on Climate Change (1996): 1996 IPCC Guidelines for National Greenhouse Gas Inventories, Reference Manual (Volume 3).
11. NIR (2013): National Inventory Report 2012 for the German Greenhouse Gas Inventory 1990-2011. Available in April 2013.
12. Rösemann C., et.al. (2013): Calculations of gaseous and particulate emissions from German agriculture 1990 - 2011. Not published yet (April 2013).
13. Stehfest E., Bouwman L. (2006): N2O and NO emission from agricultural fields and soils under natural vegetation: summarizing available measurement data and modelling of global emissions. Nutr. Cyl. Agroecosyst. 74, 207-228.
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