- Maps 1 and 2 : geographical location of New Zealand and Otago
Otago is a predominantly highland area, with large mountainous areas. It lies in the West Coast of New Zealand. New Zealand’s topography is varied with 50 percent of the land classifiable as steep, 20 percent as moderately hilly, and 30 percent as rolling or flat. Almost three quarters of New Zealand is covered by sedimentary rocks – sandstone, mudstone, greywacke, and limestone. Otago’s land use is mainly for intensive cropping for cereals, as well as intensive sheep production. However I am concentrating on the intensive arable farming in Otago.
Agrichemicals; A vast amount of agrichemicals are used on Otago’s arable farms, and when mixing and storing the chemicals and using them, the Otago Regional Council found there to be evidence of contamination in the lakes near the areas of treatment, due to accidental spills or leaks. Also there was evidence that empty containers of the chemicals were not all disposed of properly, they were just left in empty spaces on the fields, which allowed traces of it to contaminate the soil it was and wash off into water bodies by from surface runoff (where contaminants with the aid of precipitation flow overland until reaching a water body near by).
Soil compaction; is the compression or ‘squeezing’ of a soil, reducing the number of volume of large soil pores, and increasing soil density. Otago’s landscape is plain in terms of hedges, a third of all the hedges have been removed in order to it easier for machinery to operate on the land. The problem is that Otago is surrounded by mountains which direct surface run off into the farmland areas, which make the soil more susceptible to compaction by the heavy machinery.
Fertiliser use; fertiliser is a necessary part of farming; it helps the crops grow to a healthy state. Otago’s farms also showed evidence that fertilisers had been spilt then washed into local streams causing excessive algal growth in lakes, which as a result can lead to eutrophication (which starves fish in the water of oxygen causing death.
Pesticide pollution; In Otago both ground and surface waters have been influenced by pesticide pollution off intensive arable land. This results in the reduction in the quality of drinking water and necessitates expensive treatment to clean the water. Nutrients that are found in these pesticides such as phosphates can also cause eutrohication, which upsets the ecological balance and can result in undesirable effects such as fish death and algal blooms.
INTENSIVE LIVESTOCK FARMING:
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Flow diagrams 3 and 4 (above): represent the inputs, processes and outputs of two intensive livestock systems; pig farming and fish farming.
The next case study is in the Holderness, East Yorkshire. It represents the environmental problems that have been caused by intensive pig livestock units in Holderness. The following definition describes the meaning of an intensive livestock unit (ILU):
‘Buildings and associated works for the permanent indoor housing of pigs, poultry or cattle’
The Agricultural and Horticulture Census of 1994; showed a breeding herd of approximately 82’000 pigs and approximately 780’000 other pigs in Humberside. It is estimated that 65% of these (52’400 and 507’000 respectively) were in Holderness, among the highest in Europe.
Maps 3 and 4: geographical location of the Holderness in relation to Great Britain and England.
Holderness is a discrete geographical unit; a low lying peninsula bordered by the North Sea to the east, the Humber Estuary to the south, and the River Hull Valley to the west. It is formed principally of glacial boulder clay overlying chalk, although large areas in the south have been reclaimed from the estuary. It has one of the fastest eroding coastlines in the world (approximately two metres per year).
Collin Hogg BSc carried out a study to see what the environmental impacts of intensive livestock units (ILU’s) were. I have summarised his findings into the table below.
Reverting back to the generalisation:
‘Intensive farming has led to major environmental destruction’
It summarises the fact that intensive farming is an alarming process that needs to be looked at in depth in order for it to be managed efficiently (i.e. making a substantial profit at a rate to keep up with the ever increasing population), without harming, the people who use/consume the produce, people who live around areas where intensive farming systems operate, or any specie that will inevitably be effected by the processes on these farming systems.
One major aspect is the contamination of local water sources; water is a substance that we as humans need in order to survive, as well as species that inhabit the same environment as us. It is not safe for water to be contaminated by such extreme and polluting systems, especially when we don’t know the effects of some of the chemicals on humans that are being released through intensive farming methods.
I thought the aim was to produce more food to go with ever increasing population and demand, but how can we achieve this if we are not caring for the resources that help to achieve this goal – soil. Processes like soil compaction will prevent us from ever achieving this goal, as it is the soils that provide the basic nutrients for crops to grow.
There is clear evidence that intensive livestock farming is more of an alarming issue than intensive arable farming, this is due to the overwhelming negative impacts it has caused upon the human and natural environment. Intensive livestock farming can destroy or severely damage designated areas.
What have we learnt?
Referring back to the quote by Rachel Carson in her book ‘Silent Spring’, the following points should be recognised.
This book was published in 1953, but have we learnt from our mistakes? Or have we made the situation even worse? I feel that we as a society have increased the damage to the human environment; hence we have made the situation worse. If we had learnt from our mistakes than agriculture would be more extensive (have few inputs on a large area of land – an example being a hill sheep farmer where perhaps only one farmer will look after a large number of sheep, which do not take a lot of looking after), less profit orientated, be involved in a lot more mixed farms with the aim of diversifying ( where not only one type of crop, or one type of animal is farmed, except it is the reverse), and there would be less monoculture in our farming systems, where only one type of crop or animal is farmed, and be more geared towards the path of sustainability.
In terms of livestock farming solutions can be to restrict any further expansions of farms, reduce the content of chemicals like phosphorus and nitrogen in the feed for livestock, and also to keep manure properly covered to reduce ammonia emissions.
However this is a bit too much to ask in today’s world, because it seems cutting down profit may be too much to ask, so instead is it possible that intensive farming can be more sustainable?
Well a case study of a cotton fields in America demonstrates that there are certain ways to cut out the major negative factors from intensive farming – pesticides.
In this case more of the crop was being lost to pests each year and so an Internal Pest Management (IPM) advisor was employed to help find a solution. Common problems were pest resurgence (where pesticides kill the enemies of the pests as well which resulted in subsequent outbreaks or resurgence), secondary pest outbreak (an example is where one type of pest is killed, but then another type of pest emerges, because the type of pest killed used to keep the population of this new pest low, but now that it is dead, a new type of pest emerges – secondary pest) and evolution of resistance, (where pesticides had been applied so frequently that overtime some of the pest became immune to the pesticide). This led to the scenario where a wider range of pesticides were being used and their use was becoming more frequent.
By using cultural control methods (planting alfalfa in narrow strips within the field attracted the pests, as this was a preferred food) and supplying additional nutrients to increase natural predators, the problem was resolved, at a much lower cost in terms of money and the environment than the use of pesticides.
