The code is the second in a series of three. The first, published last summer, dealt with the prevention of water pollution from farms (ENDS Report 198, p 37). The third will deal with soil protection.
Unlike the water pollution code, which has statutory backing, the air pollution code does not have any legal status, although it may well be cited in future legal proceedings concerning statutory nuisances or dark smoke emissions caused by farming activities.
Most of the code provides practical advice to farmers on ways of reducing odour and ammonia emissions from livestock units and animal waste stores and disposal operations, and smoke pollution. A short final section deals with greenhouse gas emissions from agriculture.
The code is more forceful than the draft issued for consultation last summer (ENDS Report 199, pp 31-2) on a handful of issues.
MAFF has conceded, for example, that while biological treatment of livestock wastes and odour emissions is "a step beyond currently accepted good agricultural practice," such techniques "may be necessary in exceptional circumstances." It has also accepted that there are "few" circumstances where no reasonably practicable alternative to burning redundant containers of pesticides and other toxic substances in the open will be available, and hence that the exemption provided for open burning under clean air legislation will not apply.
However, the advice given on the control of ammonia emissions is virtually unchanged. Livestock contribute about 80% to the UK's total emissions of the gas, which can contribute significantly to local acidification.
However, no special measures for abating ammonia emissions are advocated by the code. Instead, it says that methods of controlling odour pollution will also be effective in abating ammonia. However, if farmers follow the advice, the odour abatement methods which are most effective in reducing ammonia emissions from livestock waste disposal to land are only likely to be used when there is a local odour problem.
The code notes that agriculture contributes 1% of the carbon dioxide, 30% of the methane, and 40-50% of the nitrous oxide emitted from all sources in the UK. All three are greenhouse gases. Only two pages of the code are devoted to giving general guidance on ways of abating these releases.