Although agriculture has been practised for thousands of years, it is probably only within the last 50 years or so that agricultural practices have become a matter of concern.
The Green Revolution, development of chemical pesticides and fertilizers, irrigation, river pollution from farm run-off, factory farming, fish farming, genetic modification, the cultivation of biofuels rather than food, the effects of climate change on farming practice and, perhaps no less important, the effect of ozone on agriculture … these are just some of the issues that are now topical and/or controversial in agriculture today.
In turn, these concerns have spawned the Slow Food Movement and encouraged the practice of organic agriculture, in which no chemical pesticides or fertilisers are used and the use of genetically modified seeds is banned.
The Green Revolution was the name given to the development of high-yielding seeds in the middle of the last century – particularly rice, wheat and maize – for cultivation in Asia and Latin America. These strains nearly always demanded high inputs of pesticides and fertilizers, not to mention irrigation, in order to perform at their best.
Although yields increased significantly as a result, some critics said that local inhabitants were suffering from malnutrition instead of dying from starvation, because the crops were predominantly destined for export but were using land that would otherwise be used for subsistence farming, i.e. to feed families.
In some places, pesticide use in rice paddies also meant the disappearance of fish and leafy weeds, which had been used by locals as vegetables. In Africa, however, there is now a call for a sustainable green revolution, which will increase yields of crops by better land management and organic practices.
The term “pesticides” is used to cover insecticides, fungicides, molluscicides, rodenticides and herbicides. Of these, insecticides are probably the most numerous and contentious, although some herbicides have also been a matter of debate.
Rachel Carson’s classic book Silent Spring, published in 1962, was the first to bring the matter to public attention by documenting the negative consequences of pesticides, particularly on birds. It is probably safe to say that pesticides have been controversial ever since. Disadvantages include disturbance to other life forms, chemical residues found on crops if they have been brought to market too early, and health effects on the farmers and farm personnel who use the chemicals. Some pesticides are endocrine disrupters – these have been shown to stimulate oestrogen receptors and can have an effect on fish after runoff into waterways.
In Europe, the EU is attempting to ban the use of the most dangerous pesticides and aerial crop spraying will also be mostly banned. The ban refers to those that are carcinogenic, mutagenic or reprotoxic; those that are endocrine disrupters, and those that take a long time to biodegrade (Persistent Organic Pollutants).
Integrated Pest Management (IPM) combines the use of pesticides with biological control methods, such as the release of parasitic ichneumon, chalcid or braconid wasps to control various insect pests such as aphids, cutworms, armyworms and codling moth. In IPM, pesticide use is kept to a minimum and used as a last resorts.
Nevertheless, organic farming is the practice of choice for those who care about the environment. For those who want to farm organically, growing “a little bit of everything” is a good maxim.
Conventional farming often involves intensively growing a single crop on large expanses of land, a practice known as monoculture. Factory farming of animals could be considered the animal equivalent, where large numbers of animals are crammed together into a relatively small space with limited movement and no access to the open air. The inhumane nature of this has encouraged more and more consumers to buy free-range eggs and meat from animals and birds that have been reared humanely. Meat-eating is actually detrimental from an environmental point of view, as grain has to be grown to feed the animals which also produce substantial amounts of methane. Lord Nicholas Stern, author of the 2006 Stern Review on climate change, recently said that people should turn vegetarian if the world was to conquer climate change, citing in particular methane emissions from the burping of cows and pigs together with the quantity of water the animals consume.
Fish farming has both advantages and disadvantages. Although it undeniably reduces pressure on wild fish, fish oil and fishmeal are produced from wild fish in order to feed the farmed fish, and this causes considerable pressure on ocean ecosystems.
In Norway, the Pollution Control Authority claims that nutrient emissions from Norway’s fish farms are the largest source of anthropogenic emissions of nutrients in coastal areas. It points out that the emissions derived from a medium-sized salmon farm producing 3120 tonnes of fish a year are equivalent to the sewage spill from a city of 50,000 inhabitants.
One of the alternatives to fossil fuels is the development of fuel ethanol and biodiesel. In 2008, 9.5 billion gallons of biofuels were grown in the US, an increase of 39% from the year before. First-generation biofuels are those where crops such as maize and rapeseed are grown for energy rather than food. But these have their drawbacks, so second-generation biofuels, in which the non-edible parts of plants or fast-growing grasses and trees are used, or third-generation biofuels such as algae are now considered a better choice by many. There are several articles on this subject in Beluga’s transport news section.
Finally, there is the ozone issue. Surface ozone forms as a result of chemical reactions between various emissions from vehicles and industry. According to a report produced by the EU-funded pollution-oriented ACCENT and EUCAARI projects, the global economic value of crop losses through surface ozone in the year 2000 was estimated to be between US $14 and $26 billion, with 40% of this cost occurring in China and India. In contrast, the global costs accrued to climate change each year are $5 billion. Wheat and soybeans are particularly sensitive to surface ozone pollution. The authors say that ozone legislation will reduce the impact of ozone pollution in China and most of the developed countries, but India, Pakistan and other developing countries will be badly affected as ozone legislation there is inadequate.
The debate around genetically modified food is covered in the Debate article of this news theme. The effects of climate change on agriculture is discussed in a special article written for this theme.