As farmers work their way through the essentials of crop husbandry and farm management, the issue of buffer zones continues to generate confusion. There are two separate buffer obligations – one is driven by nitrates requirements while the other is driven by pesticide obligations. And different rules apply to both.

However, the objective of both sets of legislation is to minimise the presence of either nutrients or pesticides in water. Separate legislation sets compliance limits with regard to either pesticides or nutrients and we are obliged to conform. Irish Water is now testing intensively so issues will arise.

The legislation uses buffer zones to help keep undesirable products out of water and so help to protect it, especially water for human consumption. The nitrates obligation is the better known of the two because it has been in existence since last year and it has formed part of the allowance within ecological focus areas (EFA) for greening for this year.

Requirement under nitrates

This obligation only applies to watercourses, as shown on 6in OSI maps by the presence of an arrow pointing in the direction of flow. The Department has shown these locations via its EFA information on the maps being used by tillage farmers for Basic Payment Scheme application. Water courses are identifiable by the fact that these features carry a 9m EFA allowance along prescribed watercourse buffers.

For the tillage farmer, the nitrates buffer requires that a 2m strip along the bank of a watercourse is not cultivated or planted to a crop (other than grass).

The objective is to prevent soil movement into water to prevent the introduction of P in particular. Some farmers have planted 3m of grass to help with maintenance along the edges.

Having this uncropped and uncultivated 2m buffer does not apply to open drains or other water-carrying bodies that are not designated as a watercourse but ther is still a 2m ban on fertilizer application.

Pesticide requirement

The rules that apply for pesticides are totally different. They apply to all bodies that can carry water, such as open drains, streams, etc, that are not formal water courses, but it also applies to water courses. So it applies to all water-carrying entities.

A second difference is the size of the buffer required. The buffer does not relate to the type of water-carrying body but rather to each individual pesticide that is being applied. In general, these vary between 15m and 1m, depending on the currently stated buffer requirement.

Product buffer requirements are shown on the product label and all pesticide products (herbicides, fungicides, insecticides, growth regulators, etc) have a minimum buffer requirement of 1m, even if nothing is stated on the label. Also, buffer requirements can change with time, so it is always good to check the Department’s website for the most up-to-date information. Buffer requirements could be increased or decreased.

Sprayer operators have an option to decrease the buffer requirement of most (but not all) individual products through use of the STRIPE initiative (see our Crop Protection 2015 magazine). This enables growers and sprayer operators to effectively reduce the buffer requirement down to the potential 1m minimum through some combination of either rate reduction and the use of reduced drift nozzles.

The specifics of this are shown on the Department’s Sustainable Use Directive web pages.

Care needed

The buffer requirements stated previously relate directly to the field operations of planting, spreading, spraying and placing controls on them to help limit the risk of undesirable contaminants getting into water. But they are not the only practices that can threaten water.

Some of you will know of the growing concern over the recent occurrences of MCPA in water. This has been a well-known issue for a number of years and so farmers should have increased awareness of the risks and act to prevent or minimise contamination of water.

However, it seems that this is not happening. It may be that those who apply products like MCPA are taking due and adequate care but more chemical active is appearing at higher levels in rivers in parts of the country. This is a real concern for all farmers. And it seems that it is not just MCPA either because other hormonal herbicides, mainly used in grassland, are also increasingly being found in water.

As well as the actual risk associated with drift movement to water, which is a definite risk, there is also concern that sprayer booms may occasionally spray directly over water or that even small quantities of raw product in the form of spills, bottle sealing foils or leaky sprayers could also result in significant direct movement to water.

And indeed losses from any of these sources may well provide a bigger threat to levels in water than spray drift. Hence the reasons for operator training and sprayer testing.

As stated previously, the concerns with regard to the presence of MCPA in water tests appear to be growing rather than abating. This was initially flagged in the very wet year of 2012, but it also known to be an issue this year. If we assume that sprayer operators are doing a reasonable job, and we must encourage that all spray application be done to the best possible standard, then we must also consider other possible leakage mechanisms that are not currently being considered.

Products like the hormonal herbicides (MCPA or 2-4,D) are regarded as being very soluble in water. This being the case then we must ask if active could be lost directly from fields treated with these products if they receive heavy rain in the days following treatment. If this could happen then farmers must avoid spraying close to heavy rain or periods of continuous rain, as it could be possible that the active can move with flowing water into streams and rivers.

Care is needed with all pesticide application and sprayer operators have a duty of care to uphold. There are very many information leaflets produced which emphasise the risks involved in spray application and advice on how best to avoid them. These are available from the EPA website at www.epa.ie/water/dw/sourceprotection.