I am studying for a PhD in Agroecology. So, I would like to write the background to my project.
Agroecology investigates the social and environmental sustainability of food production systems, or agroecosystems. The agroecosystem is defined as the interaction of biological and socio-economic systems on land used to raise food, fuel and fibre. The agroecological objective of developing sustainable agroecosystems is complex for many reasons. Some of these are as follows:
- Decisions made in non-agricultural settings (e.g. politics, economics, agribusiness) frequently result in agricultural policies and on-farm actions that focus on short-term increases in production rather than maintaining sustainable agroecosystems in the long-term. One reason for this incongruity between agricultural policy and sustainable farming is that, currently, political and economic time frames and spatial boundaries are usually too short and too small to accommodate entire agroecosystems and the ecological processes required for their sustainability.
- On an economic-political level, even though the conventional methods of farming have been demonstrated to be unsustainable and harmful to human and environmental health, there are still many obstacles to the widespread adoption of an ecologically-based farming system. One of the greatest barriers to the implementation of an ecologically-based farming system is presented by political-corporate power and vested interests in conventional farming, which are often powerful overlapping entities interlocking in such a way to ensure and reinforce their own continuation, such as suppliers of agricultural inputs (e.g., fertilizers, pesticides, veterinary drugs, genetically modified seeds), primary producers (e.g., farmers, fishermen), primary food processors (e.g., dairies, abattoirs, grain mills), secondary food processors (e.g., canneries, frozen foods, breweries), food distributors, and food retailers (see Figure 1).
- The adoption of sustainable practices is not just an unthinking response to information provided by researchers but a deliberate decision made by a farmer after reflecting on a whole range of issues.
- Many of the agricultural policies that stem from production-orientated off-farm influences have various, often deleterious, effects on biodiversity in the agroecosystem. This process of agricultural intensification produces a landscape that lacks habitat heterogeneity and results in a loss of biodiversity.
Figure 1. Productionist Agriculture reliant on fossil fuel-based inputs
One of the major factors identified as damaging agricultural systems is loss of habitat heterogeneity. Agricultural intensification has reduced habitat heterogeneity over the past 60 years. It has been associated with a loss of native vegetation and identified as a major cause of biodiversity decline in agroecosystems. In the United Kingdom (UK), for example, 116 species of farmland birds have declined by ten million breeding individuals over the past 20 years due to increases in agricultural intensification. Moreover, there is evidence of widespread bird decline, as well as declines in other taxa, such as mammals, arthropods and flowering plants, across Europe and North America following increases in farming intensity. In Australia, a reduction in habitat heterogeneity has had a part in at least 19 species of mammals becoming extinct and has adversely affected more than 82% of bird species.
The loss of habitat heterogeneity occurring in agroecosystems threatens complex interactions by replacing nature’s diversity with a small number of domesticated plants and animals. This process of habitat simplification damages ecosystem functions, which in turn reduces ecosystem services within the agroecosystem. Ecosystem functions refer variously to habitat, biological or system processes of ecosystems, such as soil formation processes, decomposition, element cycling, and trophic-dynamic regulations of populations. Ecosystem services provided by biodiversity present in ecosystems include such processes as recycling of nutrients, control of microclimate, regulation of hydrological processes, regulation of the abundance of undesirable organisms, and detoxification of noxious chemicals. An example of ecosystem services is the control of insect pest species by natural enemies such as predatory insects and parasitoids.
When ecosystem services are lacking, costly external inputs, including artificial fertilizers and pesticides, need to be applied to the agroecosystem to maintain important agricultural foundations such as soil fertility and pest regulation that would otherwise be provided by biodiversity and its concomitant services.
Although it seems to be a daunting task, there is general consensus among researchers, politicians, farmers and citizens that strong actions must be taken to move towards more sustainable methods of farming at local, regional, national and global levels.