Inemad improved Nutrient and Energy Management through Anaerobic Digestion Project/Contract number: 289712 Call identifier: fp7-kbbe-2011-5 Funding scheme: Collaborative project Document number
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- Erosion
- Leaching losses from agricultural land to surface and ground water
- Ammonia and acidifying emissions
- Greenhouse Gas Emissions
- Export of nutrients to other countries
Outflows
presents an overview of the net nitrogen and phosphate production of crops. Table : Nutrient levels of main and by-products of crops (Source: ILVO - L&M based on www.nutrinorm.nl and Campens and Lauwers (2002))
According to the 2010 Agricultural Report (LARA), the Flemish gross meat production can be estimated based on the ADSEI national production numbers, resulting in a production of around 1.4 million tonne carcass weight in 2007. The Flemish meat production is made up of 69% pork, 16% poultry and 12% beef. Moreover, during the milk campaign 2009/10 (1 April 2009 to 31 March 2010), Flemish dairy farmers supplied 1,934 million litres of milk (number based on statistics of the Department Agriculture and Fisheries). Finally, based on the data from ADSEI, the Flemish production of consumption eggs is estimated at 1,893 million eggs in 2008. There are two different ways of calculating manure production: the lump (forfaitair) system, called the gross manure production, and the nutrient balance system, called the real manure production. The former is based on the number of animals and their lump excretion coefficients while the latter uses excretion coefficients that are much closer to the real values. Within the nutrient balance system there are three different calculation methods: regression, convenant and other feeds or feedings techniques (detailed information on these calculation methods can be found in the Manure Bank’s 2009 Progress Report ‘Voortgangsrapport’) Moreover, VLM publishes a yearly document called ‘Norms and Target Values’ (‘Normen en richtwaarden’) which provides excretion coefficients, fertilization norms and spreading determination (‘uitrijbepaling’) for manure. In the stable and during storage of manure, processes take place that lead to N-emission losses. When these are taken into account and deducted from the real manure production, a number for net manure production is obtained. More information on how these calculations take place can be found in the Manure Bank’s 2009 Progress Report. In 2010, the gross production of nitrogen and phosphate in Flanders totalled 168.6 million kg N and 68.5 million kg P2O5. This number is higher than the 2009 production and is primarily due to an increase in the number of broilers, two- and three-phased other pigs and replacement livestock of 1 to 2 years of age (Voortgangsrapport 2011). The real nitrogen and phosphate production amounted to 160.2 million kg N and 60.9 million kg P2O5. The total N-loss by stable and storage emissions was 33 million kg N. This means that the net N-production was 127.2 million kg N. Most losses occurred in the poultry sector (35%), followed by pig sector (24%), other animals (19%) and cattle sector (15%). To calculate the real manure production, the Walloon Region has defined excretion coefficients (MB 07/03/2007). In the stable and during storage of manure, processes take place that lead to N-emission losses. When these are taken into account and deducted from the real manure production, a number for net manure production is obtained. More information on how these calculations take place can be found in the Manure Bank’s 2009 Progress Report. In 2011, the real nitrogen production amounted to +/- 182.8 million kg N. The total N-loss by stable and storage emissions was 30 million kg N. This means that the net N-production was 152.8 million kg N. Most losses occurred in the poultry sector (37% for broilers and 19% for laying hen), followed by pig sector (30%), and cattle sector (15%). (Gybels et al., 2009). For Belgium, in 2006, the total crop removal was 111,255 tons of N. This crop removal is calculated based on land use activity data, crop yields and the nutrient content of harvested crops (Gybels et al., 2009).
The past couple of years the amount of organic matter in Flemish agricultural soils has decreased. This decrease, coupled with significant CO2 emissions, accelerates global warming. In 2008, CO2 emissions from agricultural land (arable production and pastures) amounted to 733 ktonne and 486 ktonne respectively. This amounts to 41% of all CO2 emissions in agriculture and 15% of all greenhouse gas emission from agricultural origin (VMM, 2009). Figure presents an overview of the erosion sensitivity of Flemish soils. slightly erosion sensitive moderately erosion sensitive strongly erosion sensitive
Figure : Potential erosion sensitivity of Flemish soils (Source: LARA 2010) According to the EPICgrid model, the annual average loss of soil in Wallonia was 2.53 t/ha between 1971 & 2000 and 3.03 t/ha between 1991&2000. This evolution is due to the increasing rainfall erosion sensitivity and the increasing proportion of crop land occupied by row crops (corn, potatoes), with low ground cover in the spring, when the rains are generally more erosive. The organic matter content in the soil can also explain this trend. The past couple of years the amount of organic matter in Walloon agricultural soils has decreased. In 2006, soil with organic matter content less than the critical value of 2% represented 51% of cultivated land. They are located mainly in silty and sandy loam regions where the risk of soil erosion is particularly important. For 2005, annual average loss of soil in Wallonia was 2.9 t/ha. Figure and Figure show that the majority of the Walloon territory has a tolerable or low risk of erosion. Soil losses are less than the reference value (5t/ha.an). (Cellule Etat de l’environnement wallon, 2010)
Figure : Average losses in soil by hydric erosion in Wallonia (2002-2005) (Source: TBE 2010 – Ulg-GxABT (modèle EPICgrid)). 
Figure : Risk of hydric erosion of Walloon soils (Source: FUSAGx - UHAGx (modèle EPICgrid))
The ‘Operational Monitoring Network of Flemish Water Bodies’ contains around 220 measuring points in larger water ways that are not only subjected to the influence of agriculture but also domestic and industrial discharges. In areas with fertilizer surpluses, higher nitrate concentrations are observed, especially in winter months (Van Steertegem, 2008). In 2009/10, 33% of the measuring points exceeded the threshold of 50 mg nitrate per litre. This implies that a further reduction of nitrate losses from agriculture is necessary. The quality of the phreatic groundwater is monitored by the Flemish Environmental Agency (Vlaamse Milieumaatschappij, VMM) since 2004. In 2010, 38% of the 2000 measuring points exceeded the limit of 50 mg per litre. These results are influenced primarily by local fertilizer pressure and vulnerability of the upper aquifer (LARA, 2010). The General Direction of Agriculture, Natural Resources and Environment in Wallonia has established a nitrates monitoring network in groundwater, consisting of 950 sampling sites; a density of one point to 18 km². Over the period 2005 to 2008, 18% of the monitoring sites in vulnerable areas exceeded the limit of 50 mg per litre in the raw water (untreated). Concentrations levels, however, appear to be stable for 2 to 3 years, especially in the most extensive vulnerable areas. Figure shows the N concentration in groundwater for 2005-2008. This is not only related to the evolution of current agricultural practices (reduction of nitrogen fertilizers). The degree of contamination of groundwater depends on the effect of other factors that are difficult to control, such as rainfall, time of transfer of nitrate to aquifers (which can exceed 15 years) or even the amount of nitrogen present in the soil. (Cellule Etat de l’environnement wallon, 2010).
Figure : Average concentration in N in Walloon groundwater (2005-2008). (Source : TBE 2010 – SPW – DGO3 – DEE (base de données CALYPSO, réalisation CEEW)).
According to AMS, based on VMM, in 2009, the NH3 emission in Flanders amounted to 14.3 million kg N. This number takes into account only manure (during grazing and after application on the field) and mineral fertilizer. Agriculture is the most important source of acidifying emissions in Flanders (36% in 2008). This is mainly due to the ammonia emission as 93% of the Flemish ammonia emission originates from the agricultural sector, of which 94% originates from manure (LARA 2010). In order to reduce NH3 emissions, fertilization needs to take place using emission-poor techniques. This means that (i) during fertilization, the applied fertilizers cannot run off, (ii) ‘other fertilizers’, champost en NH3-N poor manure have to be incorporated in the soil within 24 hours, and (iii) manure and all ‘other fertilizers’ (NH3-N rich) have to be applied using emission-poor techniques. These techniques imply using injection and incorporation within 2 hours for arable land; and sod-injection, coulter-slit and trailing hoses for grassland. The ammoniac emission from manure is calculated on the basis of (i) livestock, (ii) N-excretion coefficients and (iii) NH3 – emission of stables, manure storage, pastures and fertilizer application. In 2004, the ammoniac emission from manure amounted to 36.1 million kg N, which is about 28% of the total N-emission. To reduce NH3 – emissions from livestock keeping, low-emission housing for pigs and poultry are obligatory (for new stables). In Wallonia, the agricultural sector is responsible for 30% of the total atmospheric emissions of acidifying pollutants and 93% of ammonia (NH3). As shown in Figure , ammonia comes mainly from the production and management of livestock effluents and the transformation of nitrogen fertilizers in the soil. Agricultural emissions of NH3 nevertheless declined by 10% between 1990 and 2007, due to a decrease in the production of manure and reduced use of mineral fertilizers. According to Gybels et al. (2009), the ammonia emission for 2006 in the Walloon Region was estimated at 20,041 tons N.
Figure : Emission of acidifying substances in agriculture in Wallonia
Regarding the reduction of greenhouse gas emissions and the Kyoto protocol, Flanders committed to a reduction by 5.2% of greenhouse gas emissions (equal to 22.2 Mtonne CO2 - equivalents) by 2008-2012 as compared to 1990. The Flemish agricultural sector has already achieved the target by a reduction of 18% as compared to 1990 (total emission of 8385 ktonne CO2 - equivalents). This decrease can mostly be explained by the reduction in livestock and more rational use of energy in the horticultural sector. The share of agriculture in the total Flemish greenhouse gas emission amounted to 11% in 2007. This is due to the fact that 56% of Flanders’ N2O emissions originated from agriculture, mostly directly from the soil. Moreover, 76% of Flanders’ CH4 emissions originate from agriculture as well, mostly as part of digestion processes in the livestock sector and manure (MIRA/VMM, 2010). According to the latest estimates available, anthropogenic GHG emissions in Wallonia decreased by 9.6% between 1990 and 2005. This reduction corresponds to the reduction target of Wallonia set by the Kyoto Protocol (decrease of 7.5% during the period 2008-2012). In 2007, emissions of greenhouse gas emissions from agriculture represent 9.8% of total emissions of the Walloon Region. They are mainly produced by biological processes producing CH4 and N2O (Cellule Etat de l'environnement wallon, 2010). As represented in Figure , CO2 emissions related to fuel use (agricultural machinery and heating) represent only a small fraction of total sector emissions. 40% of these emissions are CH4 emissions from enteric fermentation, almost entirely attributable to cattle. They decreased by 14.8% since 1990, mainly due to a general reduction of livestock, but also the reduced numbers of dairy cows to the profit of lactating cows. (Cellule Etat de l'environnement wallon, 2007). In 1990, the Walloon agriculture produced 4,651 kt eq CO2. In 2007, this production was 4,155 kt eq CO2, corresponding to a decrease of 10.7% (Cellule Etat de l'environnement wallon, 2010). 
Figure : GHG emissions from agriculture in Wallonia (1990 - 2007)(Source : TBE, SPW-AWAC)
For Flanders, please refer to section 3.1 and Figure on page 59. There is no data available about the export of nutrients from Wallonia to other countries. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
