Biological control can be defined as a method of controlling pests such as insects, mites, weeds and plant diseases using other organisms. It is the control of a pest by the introduction of a natural enemy or predator. It relies on parasitism, herbivory, predation or other natural mechanism with an active human management.
Different methods of pest control in organic farming are-

• Importation- a natural enemy of a pest is introduced in the hope of achieving control. E.g.- mandarin oranges protected by citrus ant.
• Augmentation- locally-occurring natural enemies are bred and released to improve control.
• Conservation- measures are taken to increase natural enemies, such as by planting nectar- producing crop plants in the borders of rice fields.

Advantages of using biological control are-

• It will only control the population of the pest they are meant to target, making it a green alternative to chemical or mechanical control methods. For example, whereas weed killing chemicals can also destroy fruit-bearing plants, biological control allows the fruit to be left uninterrupted while the weeds are destroyed.
• Natural enemies introduced to the environment are capable of sustaining themselves. After the initial introduction, very little effort is required to keep the system running fluidly.
• Biological control can be kept in place for a much longer time than other methods of pest control.
• It is cost effective in the long run.
• It is very effective in nature.
• It doesn’t involve harmful chemicals preventing their side effects to human beings.

Disadvantages of using biological control are-

• It can be fickle. While it’s supposed to manage one pest, there is always the possibility that predator will switch to a different target.
• In introducing a new species to an environment, there runs the risk of disrupting the natural food chain.
• It takes a lot of time and patience for the biological agents to work on a pest population, whereas other methods like pesticides work provide immediate results.
• They cannot completely weed out a pest. They can only reduce their numbers.
• The process of actually setting up a biological control system is a costly endeavour.

However, this is a good step towards sustainable agriculture and maintenance of soil fertility naturally. The government is also promoting this control through Paramparagat Krishi Vikas Yojana. The growing preference of upper middle class towards organic food is also creating good demand for it.

Paramparagat Krishi Vikas Yojana (Traditional Farming Improvement Programme)- has been launched by Government of India to support and promote organic farming and thereby improving soil health. This will encourage farmers to adopt eco-friendly concept of cultivation and reduce their dependence on fertilizers and agricultural chemicals to improve yields.

• Groups of farmers would be motivated to take up organic farming under Paramparagat Krishi Vikas Yojana (PKVY).
• Fifty or more farmers will form a cluster having 50-acre land to take up the organic farming under the scheme.
• Every farmer will be provided Rs. 20,000 per acre in three years for seed to harvesting of crops and to transport produce to the market.
• Organic farming will be promoted by using traditional resources and the organic products will be linked with the market.
• It will increase domestic production and certification of organic produce by involving farmers.
• The government plans to form around 10 thousand clusters in three years and cover an area of 5 Lakh hectares under organic farming.
• Government also plans to bring certification of organic produce.