Alternative and Biological Pest Controls
With an increasing population in the world, there is an increasing demand for the amount of food produced. To meet this demand, methods have been implemented that marginalize many farmers in rural communities that rely on subsistence farming. Conventional agricultural practices are designed to increase food production with few viable options for promoting the livelihoods of rural farmers to support their existence. This industrial agriculture focuses on maximizing production while minimizing labor requirements. Thus, the use of machinery, fertilizers, and pesticides are heavily relied upon with often little to no regard to the well-being of the farmers or their surrounding environments. Agroecology, seeks to promote sustainable, environmentally conscious alternatives for farmers (particularly in developing nations) with many resulting benefits, including, the increase of food and livelihoods of rural peoples.
- 1 Introduction
- 2 Context within NORA
- 3 Pest-Control Alternatives
- 4 Links
- 5 Literature
Context within NORA
Relationship to Needs
Food is one of the most important needs currently affecting the world. Sustainable alternatives to conventional pesticides promote high-yields while providing safer, healthier existences for farmers in rural areas (natural resource management). These work together to provide meaningful livelihoods for farmers by providing food at lower costs, strengthening local markets, and creating a long-term source of food for a family; all without negative impacts on the environment.
Relationships to Resources
Water, land, and living things (including humans) benefit from the reduction of harmful pesticides. Clean water and healthy soil are necessities for strengthening livelihoods of rural agricultural laborers. The goal of reducing pesticide use is to create a better environment and provide a long-term resource for farmers.
Relationship to Organizational Forms
Farmers that practice sustainable agricultural practices by eliminating the need for pesticides help their own livelihoods and their communities. Extra food produced can be sold in local markets and communities benefit from the long-term economic effects of having viable land to grow crops.
The Effects of Pesticides
Pesticides, herbicides, and insecticides are used by a variety of farmers across the globe to meet the demand of high-yields. Each year, some five billion kilograms of active pesticide ingredients are added to farms (Pretty et. al. 2003). These chemicals have many adverse effects including:
- Decreasing the health and fertility of soil, resulting in erosion and the pollution of nearby water sources
- Illness of the surrounding environment and animals in those environments (and even illness in humans)
- A dependency on these pesticides and an eventual loss in arable land
- Short-term effectiveness; insects can develop resistance to pesticides
- Harming natural predators of pests, leading to a dramatic increase in the pest population
- Reducing organic matter in soil by killing soil organisms that enhance soil fertility
Here is a diagram showing the far reaching effects of pesticides from the River Awareness Kits online knowledge hub focusing on the effects of pesticides in rivers:
These are by no mean the only results, and other negative effects have been observed (CAPSA-ESCAP). Therefore, it is important to reduce the negative impacts of pesticides to promote greater biodiversity and improve the living conditions of rural laborers.
Alternative pest control practices reduce or eliminate the use of pesticides. These ecological options improve the surrounding land and livelihood of farmers by eliminating the dependency on toxic insecticides, promoting local markets, and reducing food poverty by creating a long-term food source (Pretty et. al. 2003). These agroecological practices have shown to cost less for farmers than conventional practices, and in some cases, they cost nothing. A decrease in illness for farm laborers can also result from forgoing the use of chemical pesticides (Rasul and Thapa 2003).
It is important to promote the use of alternative methods of pest control. "Insects often evolve resistance to insecticides within a decade" (Tilman et. al. 2001). Also, insufficient diversity of crops can increase risks of pests. Pesticides make it possible for high yields to be produced in one growing season. This artificial boost to the crop does not help replenish nutrients in the soil, and ultimately leads to a decrease in output. Weak soil further limits production (Pimentel 1991). Insecticides do not have the net-benefits that sustainable methods do. Agroecological methods have proven to show significant benefits for the livelihoods of farmers and for their environments (Rasul and Thapa 2003).
Biological alternatives to pesticides are generally organic, herbal insecticides or nonhazardous techniques that do not decrease soil fertility or the health of the surrounding area. Crop rotations or diversification is another practice that involves planting different crops after a season, so as to not exhaust the soil of nutrients, or to deprive newly hatched insect pests of their food. In China, farmers have alternated planting varieties of rice to reduce pests. They have been successful in not using pesticides and increasing food production (Tilman et. al. 2003). These rotations also reduce the possibility of pests by changing the environment pests would need to grow. The rotation eliminated food sources for pests. The rotation also created a multiline – intermingling of planted crop genotypes with different disease profiles – resulting in a reduced risk of disease (Tilman et. al. 2003). Another biological alternative includes planting a buffer system around a field. This buffer system of small shrubs or grasses prevents soil erosion and increases the habitat of other animals that can control pest levels.
A popular and very successful alternative includes inter-cropping. This practice consists of alternating rows of crops that are planted in fields. This reduces the attacks of pests and is easy to implement and provides room for diversity and adaptability depending on where farmers are located (Tilman et. al. 2001). Alternating with nitrogen-fixing legumes provides for greater food production for farmers.
Another successful alternative includes the use of biological control agents. Biological control agents are natural predators of pests. Predators do not harm the crops or surrounding environment, and are used to manage pest populations. Ladybird beetles are commonly introduced to eat aphids and mealybugs (Dreistadt 2007). In some instances, promoting habitats for predators is necessary, for instance, building nests or planting trees for insect-eating birds or bats.
There are fewer non-biological alternatives, but some have proven to be very effective. Nets and small light traps are simple to create and reuse. They capture or prevent pests from reaching crops and are usually readily accessible to rural farmers. They can also be used to monitor pest populations so that farmers know whether there is a need to control them.
An important crop in Taiwan is the papaya. To avoid spraying pesticides and introducing harsh chemicals to the skin of the delicate fruits, the Taiwan Agricultural Research Institute (TARI) has developed nets that are placed around the bases of the plants to keep aphids out and retain soil moisture (2012).
Traps are also easily made from materials accessible to rural farmers.There are many programs that promote pest management methods that reduce damage to crops and the environment. A program of the USAID (IPM CRSP) has funded projects across many developing nations to promote integrated pest management practices. In Bangladesh, pheromone traps have been created to control pests in cabbage fields (2011). Specific lures (like particular floral or food items) are placed in a container with a door that lets insects in, but not out, capturing them and decreasing damage done to the cabbage.
There are many organizations in many countries that promote sustainable agricultural practices. In Asia, NGOs are working to educate farmers and influence policy decisions by governments to better the lives of rural people, especially farmers (Rasul and Thapa 2003). Below are some examples of successful reduction of pesticides in favor of alternatives.
1. In Java (the most populous island of Indonesia), the increase of plankton-feeding insects and detritivores in rice paddies has shown to increase predator populations. At mixture of organic materials left over from the previous crop cycle and non-harmful organic wastes brought in through irrigation waters is added to the rice paddies. This mixture increases natural predators by providing them with more food to build their populations. This acts as a deterrent to pests that eat rice and has not negatively altered the rest of the rice paddies (Settle et. al. 1996).
2. Pesticide usage increased in Vietnam due to great damage done to the environment after the Vietnam War in the mid to late 1900s. Farmers "indiscriminately" used pesticides in hopes of increasing yields. The government has worked with partners (like the International Rice Research Institute) to educate farmers about pesticide alternatives. Thus far, two million farmers have cut pesticide down to one spray per season and have implemented alternative options with little to no effect on crop yields. This shows that alternative practices do work, and even reducing the number of sprays makes a difference (Pretty et. al 2003).
3. In the Philippines, 75% of farmers are growing rice without the use of pesticides at all, and instead practice intercropping (Pretty et. al 2003). The FAO IPM has worked in the Philippines in to promote farmland biodiversity, provide pesticide impact assessments and promote organic agricultural practices (2013). Their research is made available for farmers and the government.
4. In rural Bangladesh, "nearly all farmers in the ecological system are controlling pests and diseases by weeding and cultivating crops in time, catching insects using nets and light traps, and by applying herbal insecticides." In 1997, a citizens' forum known as Poribesh Rakkha Shopoth (POROSH) was created to tackle Bangladesh's pollution problems and the nation's environmental movement has since grown (Rasul and Thapa 2003).
5. In Sri Lanka, 55000 farmers have limited their number of pesticide sprays from three sprays a season to 0.5 a season. This has been due to increasing awareness about the negative effects of pesticides by NGOs and government support for protecting the environment (Pretty et. al 2003). The FAO IPM has worked in Sri Lanka since 1995 to expand training programs to educate rural farmers on the benefits of using more environmentally friendly production techniques. This includes using natural manure over fertilizers, and teaching rural peoples about the negative effects of pesticides (FAO IPM 2002).
There are many strengths to switching to sustainable agricultural practices. The environmental benefits are numerous and many are listed above. The reduction or elimination of pesticides creates opportunities for farmers to increase the food production without harmful effects on the environment. Sustainable practices create long-term benefits and increase the livelihoods of farmers and their communities.
Some weaknesses include the reliance on farmers' individual initiative to implement environmentally friendly practices, and external conditions affecting them. The policies of some governments can discourage the use of sustainable practices. In developing nations, some farmers must follow the rules laid out by their landlords. Many rural farmers are tenants who rent land or work on plots of land owned by another. Landlords have the final decision on whether or not alternative agroecological practices are used since the laborers do not own the land. Landlords might also be granted funds to use harsh pesticides and other methods harmful to the environment to increase output. Some landlords might feel they have no other option but to use pesticides to meet high demands, or their existence could be threatened. This can prove to be a constraint on reducing environmental degradation. Also, governments can require certain yields be met for some crops requiring landlords to rely on the use of chemical fertilizers or pesticides. The techniques/methods, like biological control methods, also require more time for observation on the part of the farmer, and it is also vitally important that farmers are aware of how the chemicals effect their lands and their lives. In some instances, lacking educational programs and understanding can also present a major weakness.
Raising awareness and understanding of alternative pest control practices within an agroecological context among farmers, landlords, and all others concerned is critical to overcoming these barriers. More research may also be needed on specific pest control practices on particular crops in particular environments, so that they become more effective.
Dreistadt, S.H. (2007). Biological Control and Natural Enemies. Pest Notes: Biological Control and Natural Enemies, UC ANR, 74140, 1-7.
Nile River Awareness Kit. (Accessed 2014). "Physical and Chemical Characteristics of Water Quality."
Pimentel, D. (ed.) (1991). CRC Handbook of Pest Management in Agriculture. Boca Raton: CRC Press.
Pretty, J. N., Morison, J. I. L., & Hine, R. E. (2003). Reducing Food Poverty by Increasing
Agricultural Sustainability in Developing Countries. Agriculture, Ecosystems and Environment, 95, 1, 217-234.
Rasul, G., & Thapa, G. B. (2003). Sustainability Analysis of Ecological and Conventional
Agricultural Systems in Bangladesh. World Development, 3110, 1721-1741.
Settle, W., Ariawan, H., Trisatuti E., Cahyana, W., Hakim, A., Hindaya D., Lestari, A.S., and Pajarnigsh. (1996). Managing Tropical Rice Pests Through Conservation of Gernalist Natural Enemies and Alternative Prey. Ecology 77, 1975-1988.
Tilman, D., Cassman, K. G., Matson, P. A., Naylor, R., & Polasky, S. (2002). Agricultural
Sustainability and Intensive Production Practices. Nature, 418, 6898, 671-7.
Comment posting has been disabled on this doc.