What can I do in the short term?
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.
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)
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)
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 to lower risk areas e.g. 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?
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? £1,200 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? £4,500 per farm (based on farm typology used in the study) based on a loss of gross margin on 3% of the farmed area (18ha) plus establishment and topping and fencing costs in grassland fields. (2011)
What can I do in the long term?
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? £6,250 per farm, based on the farm typology used in this study, calculated on additional feed and management inputs to avoid excess N and P. (2011)
Reduce overall stocking rates on livestock farms
WHY? Reducing the stocking rate reduces the amount of nutrients and manure borne pollutants 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 £19,000 per farm. (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 volumes of surface runoff. 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? Phosphate and sediment losses would be reduced by up to 20%, nitrate leaching losses and nitrous oxide emissions would be reduced by a small (1%) amount.
WHAT IS THE INDICATIVE COST? £25-70/ha based on new hedge establishment, installing new gateways, and back fencing. (2011)
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