More than 60% of the Island is designated a Nitrate Vulnerable Zone and compliance with the regulations is one of the ‘Statutory Management Requirements’ under Cross-Compliance. If you are making a claim under the Basic Payment Scheme, Countryside Stewardship or Woodland grant you must make sure you are compliant with the NVZ requirements. Any farm could be inspected and your NVZ paperwork checked so this guide should help you get your farm practices and records in order.
Full details about the NVZ are contained in Defra’s The guide to cross compliance in England 2020.. The ten pages in that guide covering NVZ need careful reading because many different requirements apply to different farms, different soil types and to different materials containing varying amounts of nitrogen. How, when and the amount of material applied need to be carefully considered and the weather conditions assessed before entering a field. The importance of record keeping is critical to demonstrate compliance. Whilst rules, regulations and paperwork are a chore it is common sense not to waste the fertiliser you have paid for or to lose valuable farm produced materials that can improve soil condition and fertility. It is also foolhardy to apply fertilisers to any crop which is not in a vigorous growing state and able to make us of the extra boost in nutrients. Then there is the environment to consider – polluting rivers, streams and wetlands is not responsible farming and legal action can impose huge financial penalties. Below is my layman’s guide but refer to the Cross-Compliance guide for the detail.
HOW MUCH NITROGEN?
There are limits as to how much Nitrogen (manufactured and organic fertiliser) can be applied in any 12 months. This varies with the crop and the likely yield. For example, an autumn wheat crop expecting to yield 8t/ha should be limited to 220 kg/N/ha. Do check to ensure your do not exceed what is termed the ‘N max limit’. In the ‘small print’ there are lots of variations on the N max limit and more can sometimes be applied.
How much livestock manures?
Across the farm, in each calendar year, the average amount of Nitrogen in livestock manure that may be applied is limited to 170kg/ha. But since that figure is an average you could apply up to 250kg on any particular ha. This limit is both what you spread and that deposited by grazing animals. Once again there are some variations if you are a ‘Grassland Claimant’ (where more than 80% of the farm is grassland) you may be able to apply more N.
When you can and when you cannot spread organic manures
For those organic manures where more 30% of the total N content is readily available to the crop there are times when you must not spread. Clearly this requires you to know the N content. The’ closed period’ when you may not spread depends upon your farm’s soil type.
For those with grassland on sandy or shallow soils, September, October, November, and December is the closed period. On tillage land, the closed period is even earlier – August through to the end of December. You can however apply manure during August and up to mid-September where a crop has been sown on or before 15th September.
Soils that are not sandy or shallow can still receive organic manure a little later in the year, but the closed period extends into the following year. Grasslands are closed from mid-October through to the end of January and tillage land closed from October through to the end of January.
Note, for those applying slurry or poultry manure after the closed period restrictions apply to the quantities and frequency of single applications.
The Do’s and Don’ts of Spreading – avoiding pollution
First check the risks of run-off before spreading. Is the fertiliser likely to escape from the field and find its way into wetlands, springs, boreholes etc. where it will cause pollution? You must not spread manufactured fertiliser within 2m of wetland and organic manures must not be spread within 50m of a borehole or 10m of a wetland. There are many factors that affect run-off (soil type, sloping ground, weather etc.) and there are closed periods when none may be applied (see below).
Spreading must be by equipment that keeps slurry applications below 4m off the ground.
Poultry manure, slurry, digested sludge on bare soil/stubble must be incorporated within 24hours. Other organic manures must similarly be incorporated within 24 hours particularly where there is a risk of run-off on sloping ground towards wetland.
Slurry and liquid digested sludge do not have to be incorporated where applied by trailing hose, trailing shoe, dribble bar band sprayer or an injector.
As with manures, manufactured fertilisers also have closed periods. Grasslands must not be spread from mid-September through to mid-January and tillage land September through to mid-January. However, there is some degree of flexibility. Winter oilseed rape for example could receive up to 30kg/ha N during September and October and grassland up to 80Kg/ha N until November but in applications of no more than 40kg.
Planning N applications – Every application of N, both of organic manure and manufactured fertilisers, must be planned for each and every field before the tractor leaves the farmyard. First calculate how much N is in the soil that the crop can utilise. This is the ‘soil nitrogen supply’ (SNS). Various web sites provide calculators for SNS such as Tried and Tested at http://www.nutrientmanagement.org/what-we-do/calculators-and-estimators/ .
Next calculate how much N the crop will need to be applied in addition to the SNS and keep in mind there is a set limit as to how much N is allowed within the NVZ. This is the crop nitrogen requirement. For example, winter barley with an expected yield of 6.5t/ha has a limit of 180kgN/ha (see the Cross-Compliance guide for these figures).
These two figures mean you know how much N the crop needs so you can then calculate how much N any organic manure will provide on spreading known as the ‘crop available nitrogen’. This leaves the calculation on how much manufactured fertiliser is needed to ensure the crop will receive the optimum amount from the three sources: SNS, organic manure, manufactured fertiliser.
To find figures on the N content of organic manures see https://www.gov.uk/guidance/using-nitrogen-fertilisers-in-nitrate-vulnerable-zones Within that site you can download a spreadsheet for your record keeping. This is the NVZ guidance – Blank ‘farmer completion’ and ‘standard values’ table.
NVZ record keeping can be a task but some of the paperwork only needs to be done once whereas field records need to be continually updated. Some farmers find it best to keep a paper diary that can be filled in at the end of the day. That data can then be put into a table such as that above on days when not working outside. If inspected, you may need to show a number of records:
- Area of the farm
Farm map if you spread organic manure which would show:
- Each field + area
- Any sandy or shallow soils
- Sloping land where more than 12 degrees
- Field drains where unsealed and permeable
- Temporary manure field heaps
- Land with low run-off risk
- Surface waters and land within 10m
- Springs, wells and boreholes and land within 50m
Field Records- This requires a complete record for every farming operation and more…
- Crop type and date of sowing (where applying N fertiliser)
- Organic manure applications: area spread, quantity, date, how spread, type, total N content and amount of N available to the crop.
- Manufactured fertiliser: date and amount.
Grassland – Records of the previous year (to be written up before 30th April):
- Soil N supply and how it was assessed
- Crop N requirement and how it was calculated
- Any FACTS adviser’s written advice
Livestock – By 30th April of the previous year’s livestock information must be recorded which include the type (age, size etc.) and the number of days kept on the farm. This will enable a calculation of the amount of N they have produced to be recorded and that the whole farm limit of N has not been exceeded. There must also be a record of the N manure analysis and soils. For manure imported/exported record: date, type, amount, recipient/supplier and contingency plan should export fails.
An exception to the record keeping rules is that for a Low Intensity Farm. To qualify at least 80% of the farm is grassland, no more than 100kg N/ha per year is applied as organic manure and this includes what livestock will deposit. Also, less than 90 kg/ha manufactured fertiliser is spread each year and you do not import organic manure. Those (fortunate?) farmers do not have to keep a record of any fertilisers applied but nutrient planning is still necessary.
STORING ORGANIC MANURES
If you produce pig slurry and poultry manure you must have storage for 6 months output (October through to March). All other manure must have 5 months storage (October through to February). Slurry stores must also consider rainfall and any other liquids that with add volume.
Poultry and other solid manures included bedding must be stored in a vessel, or an impermeable base where run-off is collected/contained. Otherwise a roofed building or temporary field heap.
Field heaps must be at least 10m from surface waters, 30m on sloping land, ditches, land drains. They must be 50 m from springs and boreholes, moved every 12 months and not returned for two years and the locations recorded. The heap must be solid enough to be a free-standing stack that does not drain out and be covered if containing poultry litter.
SILAGE AND SLURRIES
You must notify the Environment Agency (EA) before constructing new or modifying silage or slurry storage facilities. The EA also need to be informed of where you intend to make field silage. All construction standards must be met, and EA notices complied with. Inspections of installations must be made, and repairs undertaken.