1. General context

The case study area covers two provinces in the German federal state of Lower Saxony. The northwestern province of Lower Saxony Süd-Oldenburg (districts Cloppenburg, Vechta and Oldenburg) is characterized by very-intensive pig and poultry farming, biogas plants and very high farmland (leasing) prices. Consequently, area-based surplus of farm manure is high. Since, in the northwestern region, sandy soils with small water retention capacity dominate, nutrient leaching to the groundwater bodies is potentially high as well.

In contrast, the southeastern province of Lower Saxony (e.g. the provinces Braunschweig and Northeim, the so-calles "wheat belt") is  specialized in crop production. Soil conditions are diverse (sandy to clayey). Some farms make use of biogas residues, sewage sludge and compost; however, the area-based amount of organic fertilizers applied is generally at a low level.

In Germany, local water supply companies safeguard drinking water quality, consequently they have very high interest in meeting the legal regulations set by the German Ordinance on Potable Water (TrinkwV 2016). In the past, many attempts have been made to shape agricultural management in a way that drinking water resources are less affected.

In this context, the federal chamber of agriculture (Landwirtschaftskammer Niedersachsen), which is the public advisory authority for agricultural purposes, has initiated a program that aims at closing nutrient cycles on supra-regional scale. The joint project "Farm Manure Management" ("Verbundprojekt Wirtschaftsdüngermanagement") examines the (potential) export of farm manure from surplus regions to arable farming regions.

2. The particular case of Lower Saxony and its role in FAIRWAY

As it is also true for other federal states of Germany, groundwater is the dominant source of drinking water supply in the case study districts Süd-Oldenburg (northwest) and Braunschweig/Northeim (southeast).

Average annual precipitation ranges from 750 mm (northwest) to 650 mm (southeast). Depending on soil conditions (texture, humus content, land use, etc.), annual groundwater recharge varies between 100-300 mm in the northwest and 0-200 mm in the southeast. Average annual temperature is 9.5 °C for both provinces.

Hotspots of groundwater contamination are identified by different means:

• Regular groundwater measurements and results of the groundwater monitoring in 2014 revealed striking differences between provinces. In Süd-Oldenburg annual nitrate (NO₃- ) concentrations of 81 and 140 mg/l were measured for the districts Cloppenburg and Vechta, respectively. In Braunschweig and Northeim annual nitrate concentrations in the groundwater vary between <50 mg/l to ca. 120 mg/l.
• Data on agricultural structure, land use, soil and climate was used to run a model that calculates the potential NO₃- losses to the groundwater body on district-scale (Schäfer et al., 2015). Model results show potential nitrate concentrations in the percolating water of 150 mg/l in Süd-Oldenburg and < 25 mg/l in Braunschweig and Northeim. However, due to very heterogeneous soil conditions in the southeast, locally also higher concentrations of 100-150 mg/l NO₃^- were estimated.
• Additionally, there are reports about findings of active ingredients of pesticides and their metabolites in the groundwater (NLWKN, 2016), both in the northwest and southeast. Some findings cover authorized active ingredients still being applied (i. e. Bentazon, Metalaxyl, Mecoprop) and active ingredients and metabolites that are not authorized any more (i.e. Atrazin and Desethylatrazin, Diuron, Oxadixyl, Ethidimuron, Bromacil etc.). 

Also agricultural statistics helped to identify the regions where huge amounts of farm manure are applied. Data considered

• agricultural statistics about stocking densities and farm manure storage capacities,
• data about fertilization design (computer-based),
• calculated potential of substitution of mineral fertilizers by farm manure in the southeast,
• calculated N (and P-) balances on farm-level

The management objective in the case study is to reduce groundwater pollution in the northwestern districts by supra-regional transport of farm manure (Farm Manure Management project). In a first step, the potential volume of farm manure available to export is estimated. However, the imported farm manure should not result in an aggravated situation in the farm manure receiving districts (southeast). Therefore, the second step is the identification of factors, which further decrease this volume.

The project consists of three sub-projects.

Sub-project 1 focusses on the farm manure exporting farms in the northwest. Farmers in the northwest receive professional advice about how they can meet the legal requirements with the help of farm manure export. In this way pressure on the environment (nitrate, pesticides, residues of veterinary drugs, etc.) is relieved. Issues concerning animal feeding, farm manure processing, administrative constraints and costs are considered. Desirable effects are

• an increased amount of farm manure being exported supra-regionally),
• improved N- and P-balances, N-efficiency of farms in the northwest,
• reduced amount of mineral fertilizers purchased by northwestern farmers,
• increased use of N/P-reduced animal feed,
• improved quantity of processed (phase-separated) farm manure,
• reduced nitrate concentration in percolating water and groundwater,
• reduced findings of residues of veterinary drugs in soil and water.

Sub-project 2 focusses on the transport operation itself and ways to certify the quality of the individual substrates. The goal is to develop a compulsory quality management system with impartial certification and yearly monitoring. A crucial aspect is the reliable analysis of nutrient contents in the farm manure. Thus, methods for fast analysis of nutrients are examined (e.g. NIRS) and most feasible ones are identified. Furthermore, traceability of farm manure exports and standardized documentation (e.g. with the help of GPS and barcodes) is targeted.

Expected results include

• the development of a (legally binding) quality management system for farm manure (IT-based),
• an (increased) number of certified transport agents,
• identification of methods for fast in situ-analysis of nutrients and antibiotics contained in farm manure by taking the the practical feasibility in the field into consideration.

When being carefully managed, the transport of farm manure can be a win-win business for exporting farms (release of pressure in the northwest) and importing farms (nutrients, soil fertility). Hence, it can contribute to help northwestern farms meeting the environmental standards. However, due to multifactorial reasons its impact is limited. Conceivably, the commercial processing of farm manure (resulting in single-nutrient fertilizers) can be a promising additional measure.

Sub-project 3 focusses on the farm manure receiving farms in the southeast. With the help of professional advice, it is carefully examined how farms can most efficiently make use of imported farm manure. Also factors other than economic considerations (so-called ‘soft factors’), limiting the willingness of farmers to import farm manure, are taken into account.

The following monitoring indicators are expected to be met:

• N- and P-balances of farms in the southeast below the standard of prevailing law (<60 kg/ha N and <20 kg/ha P),
• maximum application of organic fertilizers of 120 kg/ha N_org,
• limited application of imported organic fertilizers on fields with high humus content/high potential N-mineralization ,
• high N-efficiency of imported farm manure (e. g. use of nitrification inhibitors, technical innovations (injection), improved timing of farm manure application, …).

3. Mitigation measures used and preliminary results

Since professional advice concerning environmentally sound and water protecting farming has been carried out for decades in both in the northwestern and southeastern provinces by LWK (a partner organisation in FAIRWAY), problems could easily be addressed beforehand. However, the joint project Farm Manure Management implements measures on a supra-regional scale (which do not suffice on district-level only).

Measures to meet objectives in the northwest:

• Feeding regime: Farm manure often contains very high concentrations of nutrients. In order to increase nutrient efficiency in feed, animal feed rations with reduced amounts of N and P (both commercial and self-mixed rations) were tested and effects on animal health were investigated. Preliminary results show that a changed feeding towards N/P-reduced rations implicates problems concerning management and animal health. While commercially mixed rations are easy to control, self-mixed rations are difficult to handle since the quality of inputs varies substantially. There is early evidence that feed rations with reduced amounts of N and P impact on productivity and animal health. There are reports of a reduced daily weight gain, an increased amount of cannibalism, and increased occurrence of bone fractures in pigs.
• Manure storage capacity: In order to make efficient use of organic fertilizers, they should be applied during a time when plants can make optimum use of the nutrients. Hence, farm manure has to be stored durig winter for many months. However, many farms lack sufficient storage capacity. The current legal framework on fertilization (Fertilization Ordinance (DüV 2017)) exerts pressure on farmers with high stocks of animals to extend their storage capacity. In this context, the federal advisory authority for agriculture (LWK) provides professional advice (economic and legal) to farmers for such construction projects. The recently amended Fertilizer Ordinance forces farms with high stocking rates and biogas plants to provide manure storage capacity between 3-9 months, many farms work on the extension of their storage facilities.
• Farm manure export from northwestern provinces (pig, poultry, biogas) to southeastern provinces (arable): This demands cooperation between farmers in the northwest (sub-project 1) and southeast (sub-project 3) with logistics providers (sub-project 2). Secondary measures include the identification of obstacles and investigation to which extend these obstacles can be eradicated.
  - Manure processing (e. g composting of pig slurry): Farm manure with high contents of nutrients are more cost-efficient to transport., single-nutrient fertilizer are easier to handle. Thuscost-effectiveness and availability of feasible processing facilities are investigated and different methods of farm manure separation are checked.
  - Quality control and documentation: A certification procedure (legally binding) for the transport of farm manure will be developed and established. The quality of processed farm manure will be ensured by fast nutrient analysis (fast in situ-methods). An IT-based system for documentation will be developed.

Measures to meet objectives in the southeast:

1. Substitution potential for mineral fertilizers: The total volume of farm manure which can be potentially shifted to southeastern farms is estimated with the help of- farm-specific fertilization plans (IT-based). These fertilization plans have a holistic approach by combining agronomic and economic data.
   -  calculated nutrient balances of southeastern farms to help them decide whether they still meet the legal standards if they decide to import farm manure,
   -  on-farm observations and measures (soil and plant) during the growing period,
   -  an assessment of economic effects of the use of farm manure (substitution for mineral fertilizers),
   -  the standardization of quality of farm manure and the promotion of well-adjusted distribution techniques,
   -  evaluated effects on soil and water in the southeast by monitoring the nitrate concentration in the soil. 
   The analysis of IT-based fertilization plans revealed that the amount of purchased mineral fertilizers in both northwest and southeast is at a high level. Amounts of nutrients applied often exceed the (calculated) nutrient requirement of the crops. Due to cheap prices for mineral fertilizers during recent years, the competitiveness of transported farm manure is low. During the last four years before project implementation, nutrients being exported from northwestern to southeastern districts amounted to 14,700 t N/a and 10,400 t P₂O₅/a, respectively (LWK, 2017).
2. Soft factors: A survey of southeastern farmers was carried out in order to identify so-called soft (non-economic) factors which limit farmer’s engagement for manure imports. The survey revealed that apart from simple financial reasons other concerns include:
   -    lack of availability of professional support,
   -    no use of adequate technique for farm manure distribution (e. g. to avoid soil compaction),
   -    legal framework of fertilization,
   -    more challenging management of crops,
   -    fear of importing environmentally harmful substances (e g. veterinary drugs),
   -    public resistance, conflicts with neighbours.

In the first year of project implementation, only a small number of farmers was interested to implement manure cooperations. Remaining challenges include:

• Legal framework: The recently amended Fertilizer Ordinance imposes sanctions on farms that exceed thresholds of nutrient balances. Consequently, many southeastern farmers have concerns about complying with the Fertilizer Ordinance when using organic fertilizers that are more difficult to manage than mineral fertilizers. In addition, in areas were drinking water production takes place, often additional restrictions concerning the use of organic fertilizers exist. Hence, the area potentially making use of farm manure from the northwest declines substantially.
• Crop rotation: Some of the southeastern farms already have very high nutrient balances even without the import of farm manure from the northwest. Especially in rapeseed, potato and vegetable production, high N-balances are hard to avoid.
• Cost-effectiveness: Opportunity costs of purchased mineral fertilizers are low, since prices for mineral fertilizers have stagnated at a very low level.
• Soil compaction: Depending on precipitation events (i.e. very moist soil conditions), farmers in the southeast want to avoid potential soil compaction caused by heavy manure distribution machines.
• Public opinion: Many farmers are harshly critized by neighbours/in public when applying farm manure because of olfactory emissions and increased traffic.

4. Current water governance system

Actors and stakeholders involved in water governance and their roles

At a national level, laws on agricultural management (especially fertilization) and water and nature conservation exist. The federal states have to translate national targets to their own laws and have to make sure that these are met. The ministries of agriculture (ML) and nature conservation (MU) of the federal state of Lower Saxony direct these tasks to specialized public institutions. For the case study, the relevant authorities are the chamber of agriculture (LWK), the authority for water coast and nature protection (NLWKN) and the authority for mining, energy and geology (LBEG). At a district scale, monitoring takes place by the local water authorities (Untere Wasserbehörden). Furthermore, water supply companies, which have to guarantee drinking water quality, are also major players. In the northwestern districts with high farm manure surplus, only one big water supply company operates (Oldenburgisch-Ostfriesischer Wasserverband (OOWV)). Since the OOWV is very much interested in releasing pressure on the water, they also participate financially in sub-project 2, which aims at facilitating the export of farm manure. In the southeastern districts, there is a smaller water supply company (LSW Netz GmbH & Co. KG) which target sustainable use of water resources. In terms of logistics, stakeholders involved are the regional farm machinery cooperative (Maschinenring), contractors and agri-trade and feed companies (GS Agri eG, Raiffeisenbank Emsland Mitte eG)). Farmers participate on a voluntary basis.

Water quality control processes

Targets for water quality are set by the EU Nitrate Directive and translated to respective laws on national and federal state level. On national scale, the recently amended laws on fertilization (e.g. DüV 2017) impose additional targets concerning farm management (especially fertilization). The German Ordinance on Potable Water (TrinkwV 2016) defines compulsory standards for drinking water. At federal state level there are some additional restrictions (e.g. reporting requirements concerning the transport of farm manure).

On federal state level ML and MU decide whether a program should be implemented. The available data they use for decision-making, is provided by public institutions for both water and nature protection and agriculture. For example, NLWKN  (here: Gewässerkundlicher Landesdienst) collects data on water pollution, LWK compiles long-term data on applied nutrients and LBEG runs a model which calculates the potential nitrate losses to the groundwater body. In addition, water supply companies lobby for feasible solutions in the districts they operate. The joint project Farm Manure Management is the result of a cooperation between the accountable authorities for agriculture and nature and water supply companies.

Water supply companies monitor water chemical parameters. The farm management advisors of LWK monitor management practices. Monitoring includes soil and plant measures (Nmin, nitrate concentration in the plant sap, etc.). In addition, there is some reasearch going on (suction cups on a research trial installed by LBEG) in order to better understand the relationship between farm management and nitrate emissions to the groundwater on a clayey soil.

The recently amended Fertilizer Ordinance (DüV 2017) puts pressure on many farms in the northwest. This certainly creates an incentive for the farms to participate in the project. However, participation generally takes place on a voluntary basis. Therefore itt has not been regarded necessary to make agreements about conflict resolution.

Engagement and multi-actor platforms

In districts where nitrate concentrations in the groundwater have stageated at high levels, so called „round-table discussions“ have been initiated (both in northwestern and southeastern districts). Participants are representatives of district authorities for water and agriculture,  local advisory services and in some districts also converned NGOs. A district representative of the farmers is the official promoter of the meeting. However, other farmers do not participate. Since the round-table discussions have only recently been initiated, more detailed information about concrete constraints and opportunities are expected in the near future.

Note: see also

» Farm Manure Management project started
» Farm Manure Management project survey completed