What can I do in the short term?
SOIL MANAGEMENT
Cultivate compacted tillage soils
WHY? Cultivation of soils that are compacted will help increase aeration of the soil and the amount of water that can infiltrate into the soil thereby reducing runoff.
HOW? Assess compaction levels on your farm by digging holes. Depending on the depth of compaction cultivate by ploughing, subsoiling or aerating. Carry out cultivation when the soil is dry to minimise further compaction and damage to the soil.
WHAT ARE THE EFFECTS? Alleviating compaction will reduce phosphate and sediment losses in the range of 10-50%. There may also be a small reduction in direct nitrous oxide emissions.
WHAT IS THE INDICATIVE COST? £25/ha based on cultivation cost. It is envisaged that it would be applied to 20% of tillage land area each year. (2011)
Read more. For more information on compaction please click here to go to our soils page
Cultivate and drill across the slope
WHY? On fields that are gently or moderately sloping, cultivating and drilling across the slope will reduce surface runoff and where it does occur, slow the movement of soil and sediment.
HOW? If you have gentle and moderate slopes consider cultivating across the slope. However for steeper fields this is not recommended as there is a risk of overturning tractors and may channel surface runoff which can cause erosion.
WHAT ARE THE EFFECTS? The ridges created across slopes provide a barrier to surface runoff. This will mean that phosphate and sediment losses will be reduced in the range of 40-80%.
WHAT IS THE INDICATIVE COST? £10 /ha based on additional time and planning for cultivations. (2011)
Read more. For more information on reducing the risk of erosion please click here
Loosen compacted soil layers in grassland fields
WHY? When soil is compacted, the amount of water and slurry that can infiltrate into the soil is reduced. This means that there is a higher risk of losing these nutrients to the air or watercourses through runoff. If compaction is removed, then rainwater / slurry can percolate into the soil and be utilised by the grass crop. Soil aeration will be improved and result in roots being able to penetrate deeper into the soil, increasing nutrient uptake from deeper soil layers.
HOW? Loosen compacted soil by slitting / spike aeration (for shallow compaction) or subsoiling (for deeper compaction). Care should be taken in the timing of these operations, make sure the cultivation is done in moist soil conditions so as not to damage the grass.
WHAT ARE THE EFFECTS? Phosphate and sediment losses would be reduced by 10-50%. As a result of improved soil aeration direct nitrous oxide emissions are likely to be reduced and ammonia emissions reduced following slurry application (due to better infiltration).
WHAT IS THE INDICATIVE COST? £40/ha for topsoil loosening. If this was applied to 25% of grassland area this would be £10/ha. (2011)
Read more. For more information on compaction in grassland click here. To read a case study of a farmer who has started using aeration please click here
Maintain / improve field drainage systems
WHY? Functioning drainage systems allow water to move through the soil profile allowing the soil to be maintained in a well drained condition. This will extend the window of opportunity for machinery operations and livestock grazing particularly in the autumn and spring. It will also minimise the risk of poaching, compaction and waterlogging and can reduce surface runoff. Poor drainage has a big impact on crop productivity and the management versatility of the land.
HOW? Actively maintain field drainage systems through jetting, reinstallation and moling drains.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be increased by 10-50% (compared with letting drains deteriorate) and as a result of these nitrate losses, ammonium and nitrite losses would also be increased. Direct nitrous oxide emissions would be decreased as the soil will be more aerobic. Phosphate and sediment losses would be increased by up to 10% as a result of greater losses through the drain.
WHAT IS THE INDICATIVE COST? £10/ha based on the need to mole drain 20% of the farm annually. (2011)
Read more. For more information on the benefits of field drainage click here
Ditch Management
WHY? Maintaining field drainage systems and allowing them to function will reduce the risk of waterlogging, soil compaction, poaching and surface runoff.
HOW? Clean out ditches on a regular basis, this may include cutting vegetation in the bottom of the ditch to prevent flooding. It is good practice to also think about maintaining / improving field drainage systems (method above).
WHAT ARE THE EFFECTS? Nitrate leaching losses would be increased by up to 20% (this would also increase ammonium and nitrite losses as a result). Direct nitrous oxide emissions would be decreased as a result of more aerobic soil conditions. As a result of increased drainflow losses, phosphate and sediment losses would be increased by around 10%.
WHAT IS THE INDICATIVE COST? £18/ha based on contractor rates clearing 20% of ditches each year. (2011)
Read more. For more information on field drainage please click here
FERTILISER MANAGEMENT
Fertiliser spreader calibration
WHY? Inaccurate fertiliser spreaders can result in inconsistent application of fertiliser across the field. Over application can result in increased nitrate leaching losses as well as reduced crop yields through lodging. This is a low cost method that will improve crop growth and reduce diffuse pollution.
HOW? Tray tests are used to determine the co-efficient of variation (CV) and accuracy of fertiliser spreaders. A low CV (less than 10%) ensures fertiliser is spread evenly and all parts of the field receive the recommended rate. Fertiliser spreaders should be checked at least annually and ideally whenever the fertiliser type is changed.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced by up to 5% along with associated nitrous oxide emissions.
WHAT IS THE INDICATIVE COST? £150/farm (using the farm typology from the study) based on average contractor rates. (2011)
Read more. For more information on fertiliser management please click here
Use a fertiliser recommendation system
WHY? Use of a fertiliser recommendation system to plan fertiliser applications will reduce the risk of applying more nutrients than the crop needs and will minimise the risk of causing diffuse pollution and air pollution. Maintaining an appropriate balance between different nutrients (N, P and K) is also important to maximise the efficient uptake of all nutrients and reduce environmental losses.
HOW? Use a recommended system (e.g. RB209, PLANET, Tried and Tested) to plan artificial fertiliser applications to all crops, do not exceed recommended rates. Time fertiliser applications to minimise losses and take full account of nutrients in manures.
WHAT ARE THE EFFECTS? Nitrate leaching losses and phosphate losses would be reduced by up to 5%. Carbon dioxide emissions would be reduced by a small amount due to lower fertiliser use and production.
WHAT IS THE INDICATIVE COST? A saving of £5/ha on grassland, and £10/ha on arable land based on a 5% reduction in fertiliser use. (2011)
Read more. For more information on nutrient management planning please click here
Integrate fertiliser and manure nutrient supply
WHY? Studies suggest that farmers do not always make allowances for nutrients supplied in slurries and manures, when they are calculating fertiliser application rates. If allowances are made for these nutrients, in many cases this will result in a reduction in fertiliser inputs meaning reduced economic and environmental costs.
HOW? Use a fertiliser recommendation system (RB209, PLANET, MANNER) to make full allowances of nutrients supplied by organic manures. Use lab analysis to gain a better understanding of nutrient supplied by your home grown manures and slurries and deduct this from crop requirements when calculating artificial fertiliser rates.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced by up to 10%, overall manure N use efficiency would be increased and artificial fertiliser N inputs reduced. Phosphate losses could be reduced by up to 10% (from applied fertiliser).
WHAT IS THE INDICATIVE COST? Savings of £5/ha on grassland and £30/ha on arable land based on greater allowances being made for manure nutrients and reduction in fertiliser inputs. (2011)
Read more. For more information on planning manure and fertiliser use click here.
Do not apply manufactured fertiliser to high risk areas
WHY? By not applying fertiliser at any time to areas where it could easily be transferred to watercourses, the risk of nutrient pollution is reduced.
HOW? In areas in fields where there is direct access to a watercourse – don’t spread artificial fertiliser. These may include areas with a high number of open drains or next to ditches. In NVZs a no fertiliser spreading buffer zone of 2m from surface waters is compulsory.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced by a small (2%) amount, soluble phosphate losses would be reduced by up to 10%.
WHAT IS THE INDICATIVE COST? £5/ha on arable land, £1/ha on grassland based on a small yield reduction as a result of delayed fertiliser applications. (2011)
Avoid spreading manufactured fertiliser to fields at high risk times
WHY? By avoiding fertiliser spreading at high risk times the available N and P for loss in surface runoff or drainflow is reduced. Surface runoff is most likely to occur where there is rainfall on sloping ground, or when soils are wet, frozen or snow covered.
HOW? Don’t spread N fertiliser between September and February when there is little or no crop uptake and there is a high risk of nitrate leaching loss. Closed spreading periods for manufactured fertiliser N already exist in NVZs unless a specific crop requirement can be justified. Make sure you adhere to closed periods if you are in an NVZ.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced by up to 5% and phosphate losses would be reduced by up to 10%.
WHAT IS THE INDICATIVE COST? £5/ha on arable land, £1/ha on grassland based on a small yield reduction as a result of delayed fertiliser application. (2011)
Do not apply P fertiliser to high P index soils
WHY? Phosphate losses from soil by erosion increases rapidly when soil P index reaches Index 4 or above.
HOW? Losses can be minimised by maintaining soil P levels at Index 2 or by allowing the P content of high index P soils to run down over time. Sample soils regularly to ascertain what your soil’s P index is. The run down of high soil P reserves is a gradual process; the full benefits will only be achieved in the longer term (more than 10 years).
WHAT ARE THE EFFECTS? Soluble phosphate losses would be reduced by up to 50%, and particulate phosphate losses by up to 30% over the long term.
WHAT IS THE INDICATIVE COST? Cost savings of £3-6/ha based on reductions in P fertiliser on high P index soils which are estimated to be on 10% of farm area. (2011)
Livestock Management
Reduce field stocking rates when soils are wet
WHY? Soils are more easily poached and compacted when they are wet. Reducing livestock numbers or the duration of the grazing when soils are wet will reduce poaching damage and the potential for mobilisation and transport of pollutants to watercourses.
HOW? Poaching is likely to be more severe with cattle grazing than with sheep. Medium and heavy soils are more susceptible to poaching particularly in high rainfall areas. This is particularly applicable to livestock farms with high stocking rates where extended grazing or outwintering is practised.
WHAT IS THE EFFECT? Nitrate leaching losses would be reduced by up to 20% along with nitrous oxide through extended housing. Ammonia emissions would be increased by 20% through increased storage needs. Phosphate losses would be reduced by up to 10% (through lower poaching rates).
WHAT IS THE INDICATIVE COST? £0.70 – 1.80 / m3 of slurry based on additional silage production, floor scraping and slurry handling .(2011)
Read more. Work out the amount of manure or slurry that your stock is producing here
Move feeders at frequent intervals
WHY? Regular repositioning of feed troughs reduces poaching around these points and reduces the quantity of excreta deposited in any single area, both of which can increase pollution losses in surface runoff.
HOW? Move feeders frequently, especially when soils are wet. Do not site them close (within 10m) to watercourses.
WHAT IS THE EFFECT? A small reduction in nitrate leaching losses, nitrous oxide and ammonia emissions due to less compaction and poaching. Phosphate losses would be reduced by up to 10%.
WHAT IS THE INDICATIVE COST? £10-30 / ha based on moving feeders fortnightly throughout the grazing season. (2011)
MANURE MANAGEMENT
Install covers on slurry stores
WHY? Covering slurry stores reduces ammonia emissions and by diverting rainfall the volume of slurry that is collected and has to be spread is reduced.
HOW? Fit open slurry stores with a cover (these can be either rigid covers fitted with a vent or a floating flexible cover. Ensure that you have planned how to remove the rainfall from the surface of the cover. It is a good idea to then inject or band spread the slurry when applying to the fields to further reduce ammonia emissions.
WHAT IS THE EFFECT? Ammonia emissions from stores have shown to be reduced by using rigid store covers by 80%, using plastic sheeting by 60%, and using floating covers by 40%. Ammonia emissions following spreading would be increased due to the higher readily available N content and the higher dry matter content. Nitrate leaching losses would be increased by a small amount. Overall manure N use efficiency would be increased and artificial fertiliser N inputs reduced. Phosphate losses would be reduced where the cover diverts rainfall as there would be a lower volume of slurry to be spread.
WHAT IS THE INDICATIVE COST? £1.10 per m3 of slurry based on the installation of a store cover. (2011)
Allow cattle slurries to develop a natural crust
WHY? The surface crust on cattle slurry acts as a physical barrier between the ammonium nitrogen in slurry and the free air above the crust and reduces ammonia emissions.
HOW? Retain a crust on stores made up of fibre and bedding material present in the slurry for as long as possible. In most cattle systems it is possible to retain an intact crust for most of the year. Management of the slurry store in order to maintain an effective crust is critical to the success, regular agitation is not an option unless it is achieved without breaking the crust.
WHAT IS THE EFFECT? Ammonia emissions during storage can be reduced by up to 50% compared with slurry with no crust. As a result of greater readily available N content of the slurry, ammonia emissions following land spreading would be increased but by a lower amount. Nitrate leaching losses and nitrous oxide emissions would be increased by a lower amount. Overall manure N use efficiency would be increased and fertiliser N inputs reduced. Odour emissions would be reduced by the crust.
WHAT IS THE INDICATIVE COST? £0.15 per m3 of slurry produced, based on the installation and running of a larger stirrer to break up crust prior to emptying. (2011)
Adopt (batch) storage of solid manures
WHY? FIOs die off during storage, as a result there are fewer microbial pathogens in the spread manure and lower nutrient losses in run off. The readily available N content of stored FYM is lower than in “fresh” FYM due to losses during storage which will lessen nitrate leaching losses and ammonia emissions.
HOW? Store fresh solid manure in separate batches for at least 90 days before land spreading. At present around 30% of FYM and 60% of poultry manure is applied “fresh” to land.
WHAT IS THE EFFECT? Nitrate leaching losses would be reduced because of the lower readily available N content of the manure and associated Nitrous Oxide and Ammonia emissions would be reduced at land spreading. Ammonia emissions would be increased during storage but by a lower amount. The effects on nitrous oxide balances at the farm scale are uncertain.
WHAT IS THE INDICATIVE COST? £1/t of solid manure based on construction of concrete pad / leachate collection facilities and associated areas for vehicle movements. (2011)
Site solid manure field heaps away from watercourses / field drains
WHY? Keeping solid manure heaps away from watercourses and field drains reduces the risk of pollutant losses in surface runoff. This is a legal requirement in NVZ areas.
HOW? Don’t site field heaps within 10m of a watercourse or field drain. Benefits are likely to be greatest on medium / heavy soils where runoff risks are highest and field drains are likely to be present.
WHAT IS THE EFFECT? A small reduction in nitrate leaching losses and phosphate losses.
WHAT IS THE INDICATIVE COST? £1/ha based on additional time needed to plan the siting of manure heaps. (2011)
Cover solid manure stores with sheeting
WHY? Sheeting heaps provides a physical barrier preventing the release of ammonia from the manure to the air.
HOW? Cover heaps with heavy duty polythene sheet. This method is less appropriate for management systems that involve regular additions of manure to existing heaps. It is most effective when combined with incorporating manure into the soil when spread.
WHAT IS THE EFFECT? A reduction in ammonia emissions as high as 90% from storage when covered with an impermeable sheet, although nitrous oxide emissions are likely to be increased during storage. Overall nitrate losses through leaching and ammonia emissions would be decreased. Effects on balance of nitrous oxide emissions at farm scale are uncertain. Overall manure N use efficiency would be increased and artificial fertiliser N inputs reduced. Phosphate losses would be reduced due to the production of less leachate. Methane emissions would be increased due to the anaerobic conditions under the sheet.
WHAT IS THE INDICATIVE COST? £0.50/t of solid manure based on provision of plastic sheeting and additional management time. (2011)
Manure spreader calibration
WHY? Even application of manures ensures that all parts of the field receive similar amounts of total and crop available nutrients. Over application of N can result in greater potential for leaching losses and higher soil N levels.
HOW? Determine actual rate and evenness of manure applied by the spreader and adjust it to achieve the desired rate.
WHAT IS THE EFFECT? Nitrate leaching losses would be reduced by a small amount. Overall manure N use efficiency would be increased and manufactured fertiliser N inputs reduced. Phosphate losses would be reduced by a small amount from slurry applications.
WHAT IS THE INDICATIVE COST? £250 per farm based on time to assess the evenness of manure spreading and field application rates. (2011)
Do not apply manure to high risk areas
WHY? High risk areas (e.g. next to a watercourse or borehole) are able to rapidly transport manure borne pollutants to watercourses.
HOW? Do not apply manure to field areas that are high risk e.g. directly adjacent to a watercourse, borehole, road culvert, shallow soils over fissured rock, or areas with a dense network or open drains or spring lines. These areas have a high degree of hydrological connectivity between the field and the watercourse. Do not spread slurry or solid manure within 10m of a watercourse or 50m of a spring, well or borehole. This is mandatory in NVZ areas.
WHAT IS THE EFFECT? Nitrate leaching losses would be reduced by a small amount (1%) and phosphate losses by around 2%.
WHAT IS THE INDICATIVE COST? £1/ha based on additional management time to plan manure spreading activities. (2011)
Read more. For more information on how to plan manure applications please click here
Do not spread slurry or poultry manure at high risk times
WHY? The high readily available N content in slurry and poultry manure means that if it is applied at times when surface runoff or flow into drains is likely, there will be a high pollution risk. Avoiding application in autumn and early winter will help reduce over winter Nitrate leaching losses.
HOW? Don’t apply slurry or poultry manure to fields where there is a high risk or surface runoff (when soils are wet / frozen or heavy rain is expected) or late in the growing season when there is no crop to utilise the added nitrogen. Applications later in winter and spring present less of a risk as there is less opportunity for nitrate leaching before crop growth commences.
WHAT IS THE EFFECT? Nitrate leaching losses would be reduced by up to 20% of total manure N applied and associated indirect nitrous oxide emissions. Ammonia emissions would be increased by a small amount as a result of more slurry being applied to grassland soils in summer.Overall manure N use efficiency would be increased and manufactured fertiliser N use reduced. Phosphate losses would be reduced by up to 50%.
WHAT IS THE INDICATIVE COST? £1/ha based on additional time to plan manure management activities. (2011)
Read more. For more information on manure management planning please click here
Do not spread FYM to fields at high risk times
WHY? Risk of pollution is increased when solid manures are spread under conditions where heavy rain post application could transport nutrients and manure borne pollutants to surface water systems.
HOW? Avoid spreading straw based FYM to fields at times with a high risk of surface runoff. High risk times will be most frequent in winter where soils are wet, particularly in high rainfall areas.
WHAT IS THE EFFECT? Nitrate leaching losses will be reduced by a small amount (up to 5%) along with associated in direct nitrous oxide emissions. Overall crop N use efficiency would be increased (by a small amount) and manufactured fertiliser N use reduced. Phosphate losses in run off would be reduced by a small amount.
WHAT IS THE INDICATIVE COST? £1/ha based on additional management time to plan FYM spreading applications. (2011)
Read more. For more information on planning manure applications please click here
Incorporate manure into the soil
WHY? Rapid soil incorporation of manure can reduce pollutant losses in runoff and also reduce the exposed surface area of manure from which ammonia emissions can occur. Incorporation within 24hrs is mandatory in NVZ areas.
HOW? Incorporate rapidly using a plough, discs or tines, ideally within 6 hours of spreading for slurry, and 24hrs for solid manures. Ammonia emission reductions depend on the time period between manure application and soil incorporation, and on cultivation technique employed. For best results incorporate as soon as possible.
WHAT IS THE EFFECT? Ammonia emissions would be reduced by around 60% where soil incorporation by ploughing occurred 6 hours after slurry application, 40% with FYM and 70% with poultry manure which was incorporated by ploughing after 24hrs. Nitrate leaching losses and nitrous oxide emissions would be increased, however overall manure N use efficiency would be increased and fertiliser N additions would be reduced. Phosphate losses in surface runoff would be reduced.
WHAT IS THE INDICATIVE COST? £45/ha based on additional cultivation. (2011)
FARM INFRASTRUCTURE CHANGES
Resite gateways away from high risk areas
WHY? Many fields have gateways located at the bottom of the slope and near a watercourse. Gateways incur increased activity, and re-positioning gateways away from watercourses would decrease the potential for sediment and nutrient losses.
HOW? Move gates away from high risk surface runoff areas to lower risk areas on upper slopes.
WHAT IS THE EFFECT? Nitrate leaching losses would be reduced by a small amount (1%) and phosphate losses reduced by 10%.
WHAT IS THE INDICATIVE COST? £2-4/ha based on a removal of gateways and replacement with back fenced hedging on around 30% of fields. (2011)
What can I do in the medium term?
SOIL MANAGEMENT
Establish cover crops in the autumn
WHY? Without a cover crop, nitrates can be lost through over winter leaching and phosphate can be lost through sediment transport in surface runoff. Having a cover crop protects the soil from rainfall induced surface runoff and soil erosion. A cover crop will take up soil N and other nutrients after the main crop has been harvested, leaving less nitrates available for leaching.
HOW? If land is to be bare over winter establish a cover crop immediately post harvest (at the latest by mid September). Alternatively under sow spring crops with a cover crop that would be in place to take up nutrients and provide vegetation cover. In order to protect the soil surface through the surface runoff period, do not destroy the cover crop until the land is due to be prepared for the next crop.
WHAT ARE THE EFFECTS? Nitrate leaching losses of 30-60% are typical in the first year. Ammonium and nitrate losses to water and indirect nitrous oxide emissions would also be reduced by a small amount. Phosphate losses would be reduced typically between 20-80%.
WHAT IS THE INDICATIVE COST? £60/ha based on cultivating and drilling a cover crop on 70% of the spring cropping area. (2011)
Early harvesting and establishment of crops in the autumn
WHY? Earlier harvesting of crops, (especially ones that are traditionally harvested later) would enable harvesting to be undertaken when soil conditions are drier, reducing severe compaction and soil structural damage risks and associated run off of nutrients. Early establishment of new crops will enable the crop to take up some N before winter and provide good vegetation cover over the winter months to help protect the soil from surface runoff and erosion.
HOW? Harvest crops such as potatoes and maize early (in September rather than October) and then establish autumn sown crops earlier (in early October).
WHAT IS THE EFFECT? Nitrate leaching losses would be reduced by up to 30% through early winter cereal establishment and associated indirect nitrous oxide emissions. Phosphate and sediment losses would be reduced in surface run off by 20-50%.
WHAT IS THE INDICATIVE COST? For maize crops there is thought to be no associated cost as there would be no yield loss from early maturing maize varieties. (2011)
Read more. For more information on soil damage and maize harvesting please click here
Cultivate land for crops in spring rather than autumn
WHY? Autumn cultivation of land stimulates the mineralisation of N from organic matter at a time when there is little N uptake by the crop. By cultivating in spring the N will be available for uptake by the spring crops and there will be less risk of nutrient losses in surface runoff.
HOW? Cultivate arable land for spring crops in spring rather than the autumn. Plough out grassland in spring. It is mainly applicable to cultivation on light and medium soils prior to drilling spring crops or where there is a switch from winter to spring cereal cropping.
WHAT IS THE EFFECT? Nitrate leaching losses and phosphate losses would be reduced by 20-50%.
WHAT IS THE INDICATIVE COST? £100/ha based on a 25% reduction in spring combinable crop yields. (2011)
Leave autumn seedbeds rough
WHY? Leaving the autumn seedbed rough encourages surface water infiltration and reduces the risk of surface runoff.
HOW? Avoid creating a fine autumn seedbed that will slump. Reducing the number of cultivations, particularly from powered cultivation equipment will reduce the risk of surface runoff by preventing soil capping and enhancing infiltration rates. A rough seedbed also helps to break up any surface flow that is generated reducing the erosion risk.
WHAT ARE THE EFFECTS? There is limited field evidence that phosphate losses can be reduced by up to 20%. CO2 emissions would be reduced by a small amount from less cultivation.
WHAT IS THE INDICATIVE COST? £40/ha based on poorer crop establishment, and additional costs for pest and weed control. (2011)
Manage over winter tramlines
WHY? Tramlines can result in the channelling of surface water and the development of gullies on sloping erosion susceptible soils. Tramline management to improve water infiltration can help to reduce runoff and sediment loss.
HOW? Avoid the use of over winter tramlines where possible. If tramlines are present, then use tines to disrupt the tramlines to encourage infiltration of water into the soil. Use low ground pressure vehicles to help limit soil compaction.
WHAT ARE THE EFFECTS? There is limited field evidence that disrupting the tramlines can reduce phosphate losses by 30-50% on winter cereal land.
WHAT IS THE INDICATIVE COST? £10/ha based on a light cultivation to remove compaction and channelling created by tramlines. (2011)
Read more. For more information on compaction please click here
Establish in-field grass buffer strips on tillage land
WHY? Buffer strips can reduce phosphate and sediment losses by slowing surface runoff and intercepting sediment.
HOW? Designate a strip ideally located along the land contour, on upper slopes or in valley bottoms to reduce and slow down surface runoff. They are particularly suitable for fields with long slopes where high volumes of surface runoff can be generated.
WHAT ARE THE EFFECTS? Nitrate leaching loss reductions from the strip area would be similar to ungrazed grassland (about 90%). As artificial N is not applied to the buffer strips there would be a reduction in nitrous oxide emissions as well as ammonium and nitrate losses. Phosphate and sediment losses would be in the range 20-80%.
WHAT IS THE INDICATIVE COST? £1,000 per farm (based on farm typology used in study) calculated on crop yield losses and topping management with buffer strips occupying 1% of tillage land. (2011)
Establish riparian buffer strips
WHY? The buffer strip will act as a natural buffer feature to reduce the transfer of pollutants from agricultural land to water.
HOW? Establish vegetated and unfertilised grass / woodland buffer strips alongside watercourses. Ideally these strips will be free draining and have a good surface condition able to intercept surface runoff. These strips are particularly suitable for low lying and gently undulating landscapes where the topography does not concentrate the flow into channels.
WHAT ARE THE EFFECTS? Nitrate leaching loss reductions from the strip area would be similar to ungrazed grassland (about 90%). As artificial N is not applied to the buffer strips there would be a reduction in nitrous oxide emissions, as well as ammonium and nitrite losses. Phosphate losses and sediment losses would be in the region 20-80%.
WHAT IS THE INDICATIVE COST? £3,400 per farm (based on farm typology used in the study) based on a loss of gross margin on 3% of the farmed area (114ha) plus establishment and topping and fencing costs in grassland fields. (2011)
FERTILISER MANAGEMENT
Replace urea fertiliser with another nitrogen form
WHY? Urea and urea based fertilisers are associated with higher ammonia emissions than other forms of fertiliser N.
HOW? Replace urea or urea based fertiliser with another form possibly ammonium nitrate, ammonium phosphate and ammonium sulphate.
WHAT ARE THE EFFECTS? Nitrate leaching losses are likely to be increased up to 5% and associated nitrous oxide emissions by around 20% as more mineral N is retained in the soil through reduced ammonia emissions to air. Ammonia and nitrite losses to water maybe decreased by a small amount. Overall crop N use efficiency would be increased.
WHAT IS THE INDICATIVE COST? A cost saving of £5/ha as although urea is cheaper than ammonium nitrate per unit of N, higher ammonia losses from urea result in a small yield penalty compared with ammonium nitrate. (2011)
Incorporate a urease inhibitor with urea fertiliser
WHY? Urease inhibitors delay the conversion of urea to ammonium carbonate and this delay allows the urea fertiliser time to be washed into the soil, thus reducing the pH rise around the urea fertiliser. This means that ammonia emissions would be reduced.
HOW? Incorporate an inhibitor into solid urea or liquid urea / ammonium nitrate (UAN) solutions. This could be nBTPT which has been shown in trials to reduce ammonia emissions from solid urea by on average 70% and from liquid UAN by 40%.
WHAT ARE THE EFFECTS? Ammonia emissions would be reduced by around 70% from solid urea and 40% for UAN. As more mineral N is retained in the soil, nitrate leaching losses to water and nitrous oxide emissions to air would be increased by a small amount. Crop N use efficiency would also increase.
WHAT IS THE INDICATIVE COST? There is thought to be no net cost, as the costs were based on the inhibitor being added to the fertiliser at source and that the increased fertiliser costs were balanced by increased crop yields. (2011)
Use clover in place of fertiliser nitrogen
WHY? By using clover in grass swards, the need for artificial fertiliser N is reduced.
HOW? Incorporate clover into grass swards, to allow the clover to fix the N from the air. On high output systems which traditionally are reliant on fertiliser N, careful management is needed to ensure that grassland productivity is not compromised.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced by up to 20%. There would be associated reductions in direct and indirect nitrous oxide and ammonia emissions.
WHAT IS THE INDICATIVE COST? Costs are based on productivity being maintained with the cost of establishing clover in grass swards being offset by savings in fertiliser. Therefore there is no net cost.
Read more. For more information on the different ways to establish clover and the benefits of using clover click here
LIVESTOCK MANAGEMENT
Adopt phase feeding of livestock
WHY? Phase feeding allows more precise matching of feed rations to the individual animal’s nutritional requirements. Nutrients are therefore utilised more efficiently and less dietary N and P is excreted. This reduces the N and P content of manures, which reduces the potential for N and P loss.
HOW? Manage livestock in smaller groups on the basis of their feed requirements. Feed each group separately balanced rations matched to their needs.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced by up to 5% and nitrous oxide and ammonia emissions reduced by up to 5%. Phosphate losses would be reduced by up to 10% and in the longer term particulate P losses would be reduced. There may also be a decrease in methane emissions from ruminants though this would depend on the diet formation.
WHAT IS THE INDICATIVE COST? £0.75 /m3 of slurry based on collars being fitted to dairy cows along with the use of feed dispensers. (2011)
Reduce the length of the grazing day / grazing season
WHY? Patches of urine deposited by grazing livestock are a major source of nitrate leaching and nitrous oxide emissions to the air. Reducing the time animals spend at grass reduces the amount of urine deposited.
HOW? Options include keeping stock inside during the night, or by shortening the length of the grazing season. This method will have the greatest benefit in autumn as collected excreta can be returned to the fields in a more uniform and less concentrated form via slurry spreading.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced by up to 20% alongside nitrous oxide emissions. Ammonia emissions would be increased through longer housing periods by up to 20%. Phosphate losses would be reduced by up to 10% due to reduced levels of poaching damage. Methane emissions would increase as greater amounts of manure are stored. C02 emissions would increase as a result of greater forage production and manure management activities.
WHAT IS THE INDICATIVE COST? £0.70-1.80/m3 of slurry, based on the additional scraping and slurry handling along with additional silage production to feed stock. (2011)
Extend the grazing season for cattle
WHY? Urine deposited by cattle at grazing rapidly infiltrates into the soil and is associated with lower ammonia emissions compared with higher emissions from urine deposition in cattle housing. The soil prevents a physical barrier to ammonia emissions compared with urine deposited on a concrete floor in the house.
HOW? Where soil conditions allow, extend the grazing season either earlier in the spring or later in the autumn. Soil conditions are likely to limit the potential of this method on many farms because of the unacceptable level of soil damage through poaching.
WHAT ARE THE EFFECTS? Nitrate leaching losses and nitrous oxide emissions would be increased by up to 20%; however ammonia emissions would be reduced by up to 20% through lower emissions at grazing. Phosphate losses would be increased by up to 10% as a result of greater poaching damage. Methane would reduce as smaller amounts of manure are stored.
WHAT IS THE INDICATIVE COST? A saving of £0.50 per m3 slurry based on the reduced need for scraping and slurry handling together with reduced silage production. (2011)
Construct water troughs with a firm but permeable base
WHY? Using a firm yet permeable based reduces poaching of the soil around water troughs. Also as the stock gather around the troughs there is a large volume of excreta build up which can be a source of nutrients and FIOs losses to water.
HOW? Construct permeable bases for water troughs to reduce poaching. If it is necessary to move an existing trough, there will be a need to install new pipe works.
WHAT ARE THE EFFECTS? A small reduction in nitrate leaching losses, nitrous oxide and ammonia emissions would be reduced as a result of less soil compaction, and phosphate losses would be reduced by up to 10% due to lower poaching damage.
WHAT IS THE INDICATIVE COST? £2-5 / ha based on constructing a concrete base for existing troughs. (2011)
Increase scraping frequency in dairy cow cubicle housing
WHY? More frequent removal of urine and faeces from the cubicle passage floor will reduce the amount of time that ammonia emissions will occur. This will reduce the overall potential for emissions. More frequent scraping will leave a smaller pool of material from which ammonia emissions occur at any time.
HOW? Increase the number of times that cubicles are scraped from two to three (or more) times per day. It is important to use this method in combination with installing slurry store covers, allowing slurry to develop a natural crust and spreading the material with low level machines.
WHAT ARE THE EFFECTS? Ammonia emissions would be reduced by up to 20% from cubicle housing. The dry matter and readily available N content of the slurry would increase thereby meaning that there is more to lose at land spreading, as well as increased nitrate leaching losses and direct and indirect nitrous oxide. Overall manure N use efficiency would be increased.
WHAT IS THE INDICATIVE COST? £2.00 /m3 of slurry based on one extra scraping per day. (2011)
Additional targeted straw bedding for cattle housing
WHY? Increasing straw bedding use will reduce the ammonia emissions from cattle housing by providing a physical barrier between urine and the air above the bedding, and by encouraging microbial immobilisation of readily available N.
HOW? Add 25% extra straw bedding to the cattle house and target this additional straw to the wetter or dirtier areas of the house. Further reductions in emissions may be achieved by adding more than 25% extra bedding, but there is a risk that too much bedding could cause the litter temperature to rise and lead to an increase in ammonia emissions.
WHAT ARE THE EFFECTS? Ammonia emissions of up to 50% can be achieved plus lower emissions during storage and following land spreading. Nitrate leaching losses and indirect nitrous oxide emissions will be reduced by a small amount. CO2 would be increased by a small amount because of additional straw use and increased FYM amounts that need to be managed.
WHAT IS THE INDICATIVE COST? £3/tonne of FYM based on additional time to remove and spread FYM and additional straw costs. (2011)
Wash down dairy cow collecting yards
WHY? Urine deposited on collecting yard surfaces when cows are waiting for milking is a major source of ammonia emissions. Reducing the quantity of urine on the yard surface and the time that it stays there will reduce ammonia emissions.
HOW? Pressure wash these areas immediately following dairy cow use to more effectively clean the excreta. Scraping has been estimated to remove 60% of excreta from the yard surface but still leaves a film remaining from which emissions can occur.
WHAT ARE THE EFFECTS? Ammonia emissions would be reduced by up to 90% from dairy cow collecting yards. As a result of the greater readily available N content of the slurry, ammonia emissions during storage and following land spreading would be increased but by a lower amount. Nitrate leaching losses would be increased by a small amount. CO2 emissions would be increased by a small amount by additional washing and increasing the volume of slurry handled.
WHAT IS THE INDICATIVE COST? £70 per dairy cow based on an additional 25 litres of washwater per cow per day plus labour. (2011)
MANURE MANAGEMENT
Increase the capacity of farm slurry (manure) stores to improve timing of slurry applications
WHY? The collection and storage of slurry allows for more flexibility in when you apply it to the land. This should help reduce the occasions where slurry has to be spread when soils or conditions are not right, increasing the risk of surface runoff and nutrient loss, and allow slurry to be spread when the crop can utilise the nutrients.
HOW? The expansion of facilities for collection and storage of slurry will allow for better timing of application. This method is most effective when it is also implemented with applying the slurry with a low level technique (e.g. band spreading or injection) and not applying the slurry to high risk areas.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced by 10% and associated nitrous oxide emissions. Ammonia emissions would be increased by a small amount due to an increase in the slurry store surface area. Overall manure N use efficiency would be increased and artificial fertiliser N inputs reduced. Phosphate losses would be reduced by up to 20% through avoiding applications when runoff risks are high. Methane emissions would be increased as a result of longer duration of slurry storage.
WHAT IS THE INDICATIVE COST? £4/m3of slurry based on the construction of additional slurry storage. (2011)
Read more. For more help and advice on slurry and dirty water management please click here, or check out the Soils for Profit project page for further advice
Adopt batch storage of slurry
WHY? FIOs (manure borne pollutants) die off during the storage of slurry. Adding fresh slurry to stores reinoculates the slurry with viable microorganisms and so the levels do not reduce. By batch storing the slurry for at least 90 days the risk of these pollutants entering water bodies via surface runoff is minimised.
HOW? Store slurry in batches for at least 90 days before land spreading, do not add any additional slurry to the store in this time.
WHAT ARE THE EFFECTS? Methane emissions would be increased by a small amount because of the greater surface area of the slurry. FIO loss risks to surface water would be reduced by up to 90% and the BOD losses by up to 50% from managed slurry.
WHAT IS THE INDICATIVE COST? £4 /m3of slurry based on the construction of additional slurry storage. (2011)
Minimise the volume of dirty water (and slurry) produced
WHY? Minimising the volume of dirty water produced reduces the volume to be stored and spread. Farms will then be less likely to run out of storage space and be forced to spread dirty water or slurry at times where there is a high risk of runoff.
HOW? Minimise the volume of dirty water produced by: minimising unnecessary dirty yard areas, avoiding excessive use of water when washing down yards, preventing unnecessary mixing with clean water from uncovered clean yards and roofs, or roofing over yard areas and covering dirty water and slurry stores.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced by a small (1%) amount and phosphate losses by a small (2%) amount due to the better timing of dirty water and slurry applications through increased storage capacity.
WHAT IS THE INDICATIVE COST? £40/m2 of roof, based on additional roofing over dirty concrete areas and diversion of clean water. (2011)
Read more. For more help and advice on slurry and dirty water management please click here, or check out the Soils for Profit project page for further advice
Compost solid manure
WHY? As part of the composting process the manure is “sanitised” and the readily available N content is reduced, lowering the risk of manure borne pollutants and nitrate losses when the composted material is spread to land.
HOW? Encourage the breakdown of solid manure by active composting. Turn the solid manure windrow twice in the first 7 days of composting to facilitate aeration and the development of high temperatures within the windrow.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced as a result of the lower readily available N content of the manure and the lower amounts of total N in FYM and poultry manure. At land spreading nitrous oxide and ammonia losses would also be reduced. Ammonia emissions would be increased during storage but by a lower amount. Effects on the nitrous oxide balance at the farm scale are uncertain.
WHAT IS THE INDICATIVE COST? £2.60 / tonne of solid manure based on the turning of FYM windrows twice using a tractor and front end loader. (2011)
Read more. For more information on the benefits of compost click here
Store solid manure heaps on an impermeable base and collect leachate
WHY? The impermeable base and leachate collection prevents the direct loss of pollutants in surface runoff and drainflow. If manure heaps are stored directly on the soil surface leachate from the heaps will seep into the soil and / or flow over the soil surface in response to rainfall. Storage on an impermeable base will prevent seepage and accumulation of nutrients in the soil below the heap and will reduce soil compaction from farm machinery forming and spreading field heaps.
HOW? This method is of most benefit on farms with medium or heavy soil. Construct a concrete pad on which to store the heap. The leachate collected can be spread at a later date when soil conditions are suitable and the nutrients can be utilised by crops or be added back into the heap or into a slurry store.
WHAT ARE THE EFFECTS? A small (5%) reduction in nitrate leaching losses and indirect nitrous oxide losses. Ammonia emissions would be increased as a result of conserved N in recycled leachate. Overall manure N use efficiency would be increased and artificial fertiliser N inputs reduced. Phosphate losses would be reduced by a small (2%) amount.
WHAT IS THE INDICATIVE COST? £1/t of solid manure based on construction of a concrete pad and leachate collection facilities, and areas for vehicle movement. (2011)
Use liquid / solid manure separation techniques
WHY? Separating the solids from slurry means that the 2 different materials can be handled separately. This means that there is greater flexibility in manure management and application timing. This can be a useful method in helping farmers comply with N max limits in NVZ areas.
HOW? The use of a separator to remove the suspended solids from the slurry can result typically in a 5-10% reduction in the amount of pig slurry and a 15-20% reduction in the volume of cattle slurry that needs to be stored.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced by a small (2%) amount as there is less slurry to be handled and as such it is possible to get greater flexibility in application timing. The overall effect on ammonia and nitrous oxide emissions is uncertain. Phosphate losses are likely to be reduced by a small amount due to improved logistics of manure management.
WHAT IS THE INDICATIVE COST? £2-4 per m3 of slurry based on the cost of purchasing a slurry separator and a concrete pad to store the solids. (2011)
Use slurry band spreading application techniques
WHY? Ammonia volatilisation occurs from the surface of the slurry. Reducing the overall surface area of the slurry by application in narrow bands will lead to a reduction in ammonia emissions. Applying slurry beneath the crop canopy avoids contamination of the crop with slurry and reduces odour. Using these techniques delivers a more uniform slurry application.
HOW? Instead of using a splash plate slurry tanker, consider the use of a trailing hose, trailing shoe, or a band spreader. Band spreading is generally a slower operation than splash plate tankers so labour requirements need to be considered.
WHAT ARE THE EFFECTS? Ammonia emissions efficiencies for slurry spreading are typically 30% for trailing hose and trailing shoe when the grass is short and 60% for trailing shoe when the grass is long (>10cm). Reducing ammonia emissions from applied slurry will increase nitrate increase nitrate leaching losses and nitrous oxide emissions. Overall crop N use efficiency would be increased and artificial N fertiliser use reduced. Odour will also be reduced from these methods of application.
WHAT IS THE INDICATIVE COST? £1/m3 of slurry based on contractor costs. (2011)
Read more. For more information on a farmer who has implemented this technique please click here
Use slurry injection application techniques
WHY? Ammonia volatilisation occurs from the surface of the slurry. By reducing the surface area through injecting the slurry, the emissions of ammonia will be greatly reduced.
HOW? Injection can be carried out through shallow injection which places the slurry in narrow surface slots or deep injection where the slurry is placed into the soil at a greater depth behind cultivation tines. Shallow injection is most suited to grassland, whereas deep injection is most suited to arable land prior to crop establishment.
WHAT ARE THE EFFECTS? Deep injection would achieve a 90% reduction and shallow injection a 70% reduction in ammonia emissions. Reducing these ammonia emissions will increase the potential for nitrate leaching losses and nitrous oxide emissions, however overall crop N use efficiency would be increased and the need for artificial fertiliser reduced.
WHAT IS THE INDICATIVE COST? £1.50 /m3 of slurry based on contractor costs. (2011)
Read more. For more information on the different slurry application techniques please click here
Transport manure to neighbouring farms
WHY? Where there is an excess of manures (and therefore of nutrients) manures can be exported to neighbouring farmland that may have spare livestock manure N capacity. This allows exporting farms to balance nutrient inputs with the capacity of the crops to use them.
HOW? This method will be most useful on farms in NVZs where livestock manure N loadings exceed 170kg total N per ha each year. It will be most easy to implement when receiving farm holdings are in close proximity.
WHAT ARE THE EFFECTS? A reduction in nitrate leaching losses on the exporting farm and increased (to a lesser extent) on the receiving farm with capacity. Ammonia and nitrous oxide emissions and phosphate losses would also be reduced on the exporting farm.
WHAT IS THE INDICATIVE COST? £5 / m3of slurry; £4/t of solid manure based on the need to transport manure over 5km. (2011)
FARM INFRASTRUCTURE CHANGES
Fence off rivers and streams from livestock
WHY? Trampling by livestock can erode river and stream banks and increase sediment inputs to watercourses. Livestock can also add pollutants directly by urinating and defecating in the water.
HOW? Preventing access to streams and rivers as water sources for livestock can eliminate this problem. Erect stock proof fences in grazing fields and on track ways adjoining rivers and streams.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced by a small (2%) amount, phosphate and sediment losses would be reduced by up to 5%.
WHAT IS THE INDICATIVE COST? £5-15/ha based on the provision of wire fencing and water troughs. (2011)
Read more. To read more about a farmer’s experiences in Dorset regarding fencing off rivers to minimise pollution of watercourses please click here.
Construct bridges for livestock crossing rivers and streams
WHY? Where livestock ford rivers and streams they can erode banks, disturb the stream bed and increase inputs of sediment to watercourses. Provision of bridges removes the need for livestock to cross through the river thereby removing the source of pollution.
HOW? Construct bridges that allow livestock to cross without damaging the banks and that will prevent animals urinating and defecating in the river.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced by a small (2%) amount; there would be a small increase in ammonia emissions from urine on the impermeable bridge surface. Phosphate and sediment losses would be reduced by a small (5%) amount.
WHAT IS THE INDICATIVE COST? £5-30/ha based on the construction of 2 bridges per farm. (2011)
Farm Track Management
WHY? Farm tracks can become conduits for nutrient and manure borne pollutants to be lost through surface runoff. On sloping land in wet conditions these tracks can become degraded quickly and form channels that will take large volumes of runoff. Waterlogged tracks can also cause damage to livestock including problems with lameness, mastitis, and teat and udder injuries.
HOW? Create well drained tracks with appropriate surfaces, avoiding routes with steep slopes, and avoiding directing runoff towards bare soil, roads or watercourses. Manage your tracks by improving track surfaces and repair damage promptly, and provide good drainage and divert runoff to adjacent grassed areas, soakaways or swales.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced by a very small (1%) amount and phosphate and sediment losses by a small (2%) amount, manure borne pollutants would be reduced by a small amount.
WHAT IS THE INDICATIVE COST? £1-3/ha based on digging out a soakaway and installing drains across farm tracks, plus maintenance and clearing out every 4 years. (2011)
Read more. For more information on opportunities for help and advice under Catchment Sensitive Farming please click here
Establish tree shelter belts around livestock housing and slurry storage facilities
WHY? The tree shelter belt will disrupt air flows around the building or slurry storage facility reducing ammonia emission rates and will directly recapture a proportion of the emitted ammonia. The trees planted will also recapture a proportion of the emitted ammonia.
HOW? Plant tree shelter belts around livestock housing and slurry storage facilities. The effectiveness of the method in reducing ammonia emissions will depend on the height and canopy density of the shelter belt and environmental conditions. A shelter belt of sufficient height to be effective will take a number of years to establish.
WHAT ARE THE EFFECTS? Ammonia emissions could be reduced by up to 10%.
WHAT IS THE INDICATIVE COST? £400 for dairy farms based on the establishment of a 30m deep shelter belt around the perimeter of the livestock building / slurry store over 20 years. (2011)
What can I do in the long term?
SOIL MANAGEMENT
Adopt reduced cultivation systems
WHY? Reduced or no till cultivations rather than ploughing can retain the soil surface organic matter and preserve good soil structure with the resulting soil conditions improving water infiltration rates thereby reducing loss risks of phosphate and sediment.
HOW? Reduce cultivations using discs or tines to cultivate the soil surface as the primary cultivation in seedbed preparation (typically at 10-15cm cultivation depth) Consider direct drilling or broadcasting of seed. It is most common on medium and heavy soils and is less likely to be adopted in wetter parts of the country.
WHAT ARE THE EFFECTS? Nitrate leaching losses can be reduced by up to 20%, with indirect nitrous oxide emissions reduced as well. There is some evidence of increased direct nitrous oxide emissions. Phosphate and sediment loss reductions can be up to 60% on medium and heavy soils and up to 90% on light soils. CO2 emissions would be reduced as a result of lower power requirements of reduced and no till management systems. Soil carbon storage would be increased by a small amount.
WHAT IS THE INDICATIVE COST? A saving of £40 per ha based on selling most cultivation equipment and using a contractor. (2011)
Read more. For more information on reduced cultivation and to read the experience of a farmer who has stopped using his plough please click here
Allow field drainage systems to deteriorate
WHY? Drainage systems can accelerate the movement of pollutants from land to a watercourse by acting as an easy flow route. Allowing drainage systems to deteriorate therefore reduces connectivity and the potential for these pollutants to be transferred into watercourses, although there would be an increase in surface runoff.
HOW? Allow existing drainage systems to naturally deteriorate over time. It is probably that with increasing soil wetness it would be necessary to reduce the length of the grazing season or to reduce the stocking rates.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be in the range of 10-50%, as well as indirect nitrous oxide emissions, ammonia and nitrite losses. However direct nitrous oxide emissions would be increased as a result of wetter soil (through no drainage). Phosphate losses would be reduced by up to 10% provided that the stock were removed in wet conditions.
WHAT IS THE INDICATIVE COST? £50/ha for arable land and £10/ha for grassland based on estimated yield losses of 5-10% due to poor drainage. (2011)
CROP AND LIVESTOCK BREEDING
Make use of improved genetic resources in livestock
WHY? Incorporation of health and robustness characteristics into selected breeding programmes could result in improved nutrient use efficiency within livestock systems.
HOW? Use genetic manipulation to improve the lifetime efficiency of livestock systems. The more productive an animal can be during its life, the less impact it will have per kg of meat or litre of milk produced.
WHAT ARE THE EFFECTS? Nitrate leaching losses, nitrous oxide and ammonia emissions would be reduced by up to 10% from manure management. Phosphate losses would be reduced by 10%, with potential methane loss reductions of up to 10%.
WHAT IS THE INDICATIVE COST? £80 per dairy cow based on estimates of the ability to reduce input costs by around 10% for the same livestock outputs. (2011)
Read more. For more information on livestock productivity and its relationship to emissions please click here
Use plants with improved nitrogen use efficiency
WHY? During the growing period the efficiency of fertiliser nitrogen uptake by the plant varies quite widely according to site conditions, soil N and plant physiology. If the plant can be made to be able to use more of the soil N, there would be expected reduced emissions of N to water and the air. Improving N use efficiency could potentially reduce fertiliser N additions.
HOW? Develop new plant varieties with improved genetic traits for the capture of soil N.
WHAT ARE THE EFFECTS? Nitrate leaching losses, ammonia emission and nitrous oxide emissions would be reduced by up to 10%. A small reduction in CO2 emissions would be experienced due to lower fertiliser N use.
WHAT IS THE INDICATIVE COST? £20/ha based on reduced fertiliser N inputs of 10% for the same amount of crop production. (2011)
FERTILISER MANAGEMENT
Reduce manufactured fertiliser application rates
WHY? Limiting the amount of N fertiliser that is available to crops will reduce the quantity of nitrate left in the soil post harvest. Limiting phosphate fertiliser will in the short term reduce the amount of soluble P lost and in the long term will reduce the amount at risk of loss as particulate P.
HOW? Reduce the amount of manufactured N and P fertiliser applied to crops below the economic optimum rate. This would have a significant impact on crop yields (other than legumes).
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced by up to 10% (from a 20% reduction in N fertiliser rates) as well as reductions in nitrous oxide and ammonia emissions. Phosphate loses would be reduced by up to 10%, plus longer term reduction through reduced soil P status.
WHAT IS THE INDICATIVE COST? A reduction in gross margin at a cost of £10,200 calculated on the farm typology used in this study. (2011)
Use nitrification inhibitors
WHY? Nitrification inhibitors are chemicals that slow the rate of conversion of ammonium to nitrate, so that nitrate is formed at a rate that is in better synchrony with crop demand (i.e. slow release) and will thereby increase N use efficiency and reduce nitrous oxide emissions and nitrate leaching losses.
HOW? Add nitrification inhibitors to applied artificial fertilisers, organic manures and grazed pastures or to grazing stock.
WHAT ARE THE EFFECTS? Nitrate leaching losses of up to 35%, and direct nitrous oxide emissions of up to 70%. Ammonia emissions to water and air may be increased by a small amount. There is ongoing Defra research into the potential of nitrification inhibitors to reduce emissions.
WHAT IS THE INDICATIVE COST? £20/ha based on purchase costs. (2011)
Reduce dietary N and P intakes
WHY? Avoiding excess dietary N and P in the diet and / or making dietary N and P more available allows nutrient concentrations in the diet to be reduced without affecting animal performance. This will mean that the amount of N and P excreted either directly to fields or via handled manures is reduced.
HOW? Adjust the composition of livestock diets to reduce the total intake of N and P per unit of production. This may be achieved by restricting diets to recommended levels of N and P, or by changing the composition of the diet to increase the proportion of dietary N and P utilised by the animal. Benefits are likely to be greatest on dairy, pig and poultry units.
WHAT ARE THE EFFECTS? Nitrate leaching losses, nitrous oxide and ammonia emissions would be reduced by up to 10%. Phosphate losses would be reduced by up to 10% and in the longer term particulate P losses would be reduced.
WHAT IS THE INDICATIVE COST? £45/dairy cow based on additional feed and management inputs to avoid excess N and P. (2011)
LIVESTOCK MANAGEMENT
Low methane livestock feeds
WHY? Developing a low methane diet for ruminants could significant reduce methane emissions as fermentation in the rumen accounts for about 80% of methane emissions from agriculture.
HOW? Formulate livestock rations to minimise the potential for methane production from rumen fermentation.
WHAT ARE THE EFFECTS? Still under development
WHAT IS THE INDICATIVE COST? Still under development
Reduce overall stocking rates on livestock farms
WHY? Reducing the stocking rate reduces the amount of nutrients and manure borne nutrients in manures and slurries. Associated fertiliser N inputs and poaching risks would be reduced.
HOW? Reduce the total number of livestock on the farm. A smaller number of animals will also produce less manure which would ease pressure on manure storage capacity and provide greater flexibility in application timing.
WHAT ARE THE EFFECTS? Nitrate leaching losses, nitrous oxide and ammonia emissions would be reduced by up to 20%, and phosphate losses reduced by 30%. Manure borne pollutants, methane, and carbon dioxide emissions could all be reduced by up to 20%.
WHAT IS THE INDICATIVE COST? Based on a loss in gross margin through a 20% reduction in livestock numbers, on the farm type used in the study a loss of £11,000 per farm. (2011)
Outwintering of cattle on woodchip standoff pads
WHY? Ammonia emissions from urine deposition onto a woodchip standoff pad are likely to be lower than from a concrete yard or cattle housing due to rapid infiltration into the woodchip matrix. The woodchip present a low runoff risk.
HOW? Construct purpose built woodchip pads that include an impermeable liner and drainage collection system with a feeding area instead of winter housing.
WHAT ARE THE EFFECTS? Nitrate leaching losses are likely to be lower as a result of lower volume and N content of the leachate from the woodchip pads (compared with slurry spreading from cattle housing). Ammonia and nitrous oxide emissions at land spreading and ammonia from the woodchip pad are likely to be lower. Phosphate losses are likely to be lower as a result of the lower volume and P content of the leachate compared with slurry. Methane emissions will be reduced as stored leachate volumes are lower than from cattle housing.
WHAT IS THE INDICATIVE COST? £50/head of cattle based on the need to excavate to 0.75m depth, line the pad and install drainage. (2011)
MANURE MANAGEMENT
Anaerobic digestion of livestock manures
WHY? Methane generated from livestock manures during AD can be used to produce heat and power, and to replace fossil fuel use. Methane emissions during subsequent manure storage prior to land spreading are also reduced.
HOW? Farms with significant numbers of housed livestock would be the most suitable for on farm installations because of the significant costs involved.
WHAT ARE THE EFFECTS? Methane emissions from slurry storage would be reduced, plus heat and power would be produced. An increase in the readily available N content of the digestate would increase ammonia emissions during storage and following land spreading. Nitrate leaching losses would be increased by a small amount. Overall manure N use efficiency would be increased.
WHAT IS THE INDICATIVE COST? £13,000 per farm type used in the study (114ha) for the capital costs. (2011)
Change from a slurry to solid manure handling system
WHY? Solid manures are more easily stored than slurries and present less of a risk of pollutant loss during and following land spreading. Straw use also encourages bacterial immobilisation of readily available N resulting in a lower potential for ammonia emissions during housing, storage or spreading.
HOW? This method is potentially applicable to cattle and pig farms with housed stock that handle all or part of their manure as slurry. This method would entail changing from this system to one where animals are kept on bedding (e.g. straw) to produce solid manure.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be reduced by up to 50%, nitrous oxide and ammonia emissions at land spreading would be reduced as a result of the lower readily available N content. Phosphate losses would be reduced because of lower runoff risks. Methane emissions would be lower from solid manure systems. CO2 emissions could be increased through the additional handling of manure.
WHAT IS THE INDICATIVE COST? £15,000 for the dairy unit based on changes to livestock buildings for housing, straw costs and additional labour requirements. (2011)
Change from a solid manure to a slurry handling system
WHY? Slurry based systems have a greater risk of pollutant losses during and following land spreading. However solid manures can contain high amounts of nitrous oxide that will be emitted from storage facilities and on bedding from housing, whereas slurry emits little or no nitrous oxide from slurry based buildings or stores.
HOW? Change from a system where the manure from housed animals is collected as a solid to one where animals are kept on a liquid based system. This system will require storage facilities that may not have been required for storage of solid manure.
WHAT ARE THE EFFECTS? Nitrate leaching losses would be increased by up to 50% as well as nitrous oxide and ammonia emissions at land spreading as a result of the higher readily available N content of slurry. Ammonia emissions would be increased during housing and storage. On balance nitrous oxide would probably be reduced. Phosphate loss would be increased as a result of higher runoff risk. Methane emissions would be increased from slurry compared with solid manure storage.
WHAT IS THE INDICATIVE COST? Based on the farm type used for this study a cost of £14,000 has been assigned based on the installation of cubicles and construction of slurry storage tank. (2011)
FARM INFRASTRUCTURE CHANGES
Establish new hedges
WHY? Increasing the number of hedgerows can help to reduce sediment and associated nutrient losses by trapping and lowering surface runoff volumes. Hedges can also help to protect soils from wind erosion.
HOW? Plant new hedges along fence lines and use them to break up the hydrological connectivity of the landscape.
WHAT ARE THE EFFECTS? Nitrate leaching losses and nitrous oxide emissions would be reduced by a small (1%) amount, phosphate and sediment losses would be reduced by up to 20%.
WHAT IS THE INDICATIVE COST? £25-70/ha based on new hedge establishment, installing new gateways, and back fencing. (2011)
Establish and maintain artificial wetlands
WHY? Constructed wetlands can be used for the treatment of lightly contaminated runoff from farm hard standing areas and to intercept runoff water from a field or group of fields. They can trap sediment and reduce pollutant loads in water.
HOW? Construct or establish wetlands with fences and channels that will be sufficient to capture runoff and sediment from a field group or hard standing.
WHAT ARE THE EFFECTS? Nitrate losses could be reduced by 20%; however nitrous oxide emissions from the wetland may be increased. Phosphate losses would be reduced by up to 80% from arable fields. FIO losses would be reduced by up to 90%, methane and C02 emissions are likely to increase.
WHAT IS THE INDICATIVE COST? £15/ha of arable land, based on a wetland system (covering 0.25% of arable area) and associated crop production losses. (2011)
LAND USE CHANGE
Convert arable land to unfertilised and ungrazed grass
WHY? There are only small losses of nitrates in drainage waters from grasslands when compared with arable land. The permanent vegetation cover minimises the erosion of soil particles and phosphates in surface runoff.
HOW? Change the land use from arable cropping to unfertilised grassland (without livestock) and associated manure inputs.
WHAT ARE THE EFFECTS? Conversion to ungrazed grasslands would reduce nitrate leaching losses by 90%. Nitrous oxide and ammonia emissions would be reduced by around 90%. Phosphate and sediment losses in runoff would be reduced by about 50%.
WHAT IS THE INDICATIVE COST? £100/ha based on a reduction in cropped area of 10% of arable land. (2011)
Arable reversion to low fertiliser input extensive grazing
WHY? N uptake by permanent grassland and immobilising N into accumulating soil organic matter provides a long term sink for N. There are only small losses of nitrate in drainage waters from arable reversion grasslands. The permanent vegetation cover minimised the erosion of soil particles and loss of associated P in runoff.
HOW? Change the land use from arable cropping to permanent grassland with a low stocking rate and low fertiliser inputs.
WHAT ARE THE EFFECTS? Conversion to extensive grazed grass would reduce nitrate leaching losses by around 80-90%. Ammonia and nitrite losses to water would also be reduced. Ammonia emissions from excreta in the field and handled manures would be increased. Phosphate losses would be reduced by around 50%. There would be a reduction in energy use and an increase in carbon storage in the grassland soils.
WHAT IS THE INDICATIVE COST? £100/ha based on the arable reversion to lowland grazing. (2011)
Convert arable / grassland to permanent woodlands
WHY? There are only small losses of nitrate in drainage waters from permanent woodlands and the permanent cover provided by leaf litter mulch and vegetation minimises the erosion of soil particles and loss of phosphate in surface runoff.
HOW? Change the land use from agricultural land to woodland. This method is more applicable to marginal arable land with a high erosion risk and / or close to surface waters. This is an extreme change in land use and is likely to be suitable for areas where converted land would have amenity and conservation value.
WHAT ARE THE EFFECTS? Conversion to woodland would reduce nitrate leaching losses by around 90%. Nitrous oxide and ammonia emissions would be reduced by around 90% as no fertiliser N would be applied. Phosphate losses would be expected to be reduced by around 50% provided best management practices were adopted. Converting to permanent woodland would increase soil carbon storage.
WHAT IS THE INDICATIVE COST? £150/ha based on a whole life cycle cost / income over 75 years. (2011)
Convert land to biomass cropping
WHY? Cultivation of arable land stimulates the mineralisation of organic matter, the release of soil N and carbon. Following establishment of perennial biomass crops, soils are not cultivated annually, reducing nitrate leaching losses. Lower levels of fertiliser N are used compared with arable crops, which reduces nitrate leaching losses.
HOW? Grow perennial biomass crops for example willow, poplar, and miscanthus to displace fossil fuel use, either through direct combustion or through bio fuel generation.
WHAT ARE THE EFFECTS? A reduction in nitrate leaching losses, ammonia emissions and nitrous oxide emissions of up to 50%. Phosphate losses in surface runoff reduced by up to 50% provided best soil management practices were adopted. Increased soil carbon would be in the range 1.9 to 7.0t C02e/ha/yr.
WHAT IS THE INDICATIVE COST? A saving of £10/ha based on planting 25% of farmland area and no planting grants. (2011)
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