13 August 2018 Read: 495
Intercropping is the practice where two or more crops are planted alongside one another in the same field. The most common goal of intercropping is to produce a greater yield in a given piece of land by making use of resources or ecological processes that would otherwise not be utilized by a single crop.
When deciding to practice intercropping, research and careful planning are required. It is extremely important not to have crops competing with each other for physical space, nutrients, water and sunlight. Other factors to take into consideration when deciding on crops for intercropping are type of soil, climate, rainfall, pollination requirements, disease risks and possible risk reductions etc.
Examples of intercropping strategies are planting a deep-rooted crop with a shallow-rooted crop, or planting a taller crop with a shorter crop that requires some shade. When crops are correctly selected, other agronomic benefits are also achieved.
Planting two crops adjacent to each other can be especially beneficial when the two plants have a mutually beneficial symbiotic relationship, where both plants can benefit from the presence of the other. For example, lodging-prone plants (plants that are prone to tip over in wind or heavy rain) may be given structural support by their companion plants. Some plants are used to suppress weeds or to supply nutrients. Light-sensitive plants may be given shade or protection on otherwise wasted space of unutilized land. An example is the tropical multi-tier intercropping system used where coconut occupies the upper tier, bananas the middle tier and pineapple and ginger utilizes the lowest tier. Intercropping does not only attract insect biodiversity but also encourages a larger biodiversity of soil organisms that would otherwise not be available in a single-crop ecosystem. These organisms may provide crops with valuable nutrients such as through nitrogen fixation.
Maximize land use;
Offer competition for weeds in respect of soil nutrients;
Creating greater biodiversity especially amongst insects with a result in both predatory insects and insects assisting in pollination being attracted;
Create greater yield without increasing land use.
Types of intercropping:
Mixed or multiple cropping is when two or more crops are simultaneously and randomly cultivated on the same field without any row formation;.
Relay cropping is the growing of two or more crops with the planting of the secondary crop after the first crop has completed development;
Row intercropping is the cultivation of two or more crops on the same field with a formal row arrangement. The planting of the crops occur simultaneously;
Strip intercropping can be divided into contour strip cropping and field strip cropping. This is the cultivation of various crops in alternate strips of the same width on the same field.
Types of intercropping focusing on pest management:
There are several ways pests can be controlled through intercropping:
Trap cropping involves intercropping with a plant that is more attractive for pests compared to the main production plant. The pests will focus on attacking the trap crop rather than the production crop;
Repellant cropping uses a plant that has a repellent effect to certain pests that attacks the production plant. This system involved the repellant crop masking the smell of the production crop.
Push-pull cropping is a mixture of trap cropping and repellant cropping. Attractant crops are used to attract pests away from production crop whilst repellant crop is used to repel the pests away.
Advantages of intercropping
It reduces plant diseases. The distance between crops of same species is increased by means of crops of a different family group that are planted in between. Diseases can therefore not be as easily transferred from row to row;
Is an easy and profitable practice for organic farming;
Contour strip cropping reduces hillside erosion and protects topsoil;
Creates greater biodiversity especially amongst insect species, attracting beneficial insects especially when flowering crops are included in the intercropping system. It also attracts predatory insects that can help reduce harmful insects and mites on crops;
Minimizes labour costs on controlling and eradicating weeds, as well as costs such as fertilizing, irrigation and general maintenance.
Utilizes soil usage more efficiently, resulting in a increased yield of two or more crops being harvested of the same space of land;
Creates increased total production and farm profitability.