Intercropping in farming systems involves the growing of two or more crops in close proximity. A common purpose of intercropping is to produce higher yields by planting crops which use different resources in the soil and to reduce weeds. Intercropping increases crop yield and aides in reducing crop disease by improving the microclimate in fields. Intercropping takes into account soil composition, climate, and crop varieties which do not compete with each other for physical space, nutrients, water, or sunlight. Intercropping works well with crops which have different root systems heights, light and nutrimental requirements. For instance maize yield increased when corn was intercropped with soybean.
Intercropping or companion planting can also work to assist crops supporting each other structurally such as creeping or lodging-prone plants (plants which may tip over in heavy wind or rain). Other intercrops can be used to suppress weeds or provide nutrients to soil in a similar way to crop rotation whereby nutrient fixing and nutrient dependent plants work to complement each other.
Another important feature of intercropping is encouragement of biodiversity which can protect against outbreaks of crop pests by providing a habitat for a variety of insects and soil organisms that would not be present in a mono-crop. Biodiversity increases the diversity and abundance of natural enemies.
Different methods of intercropping are mixed, which involves mixes the crops, row cropping which is cropping in rows and includes crops in rows which alternate. Variations of row cropping include alley cropping, which is growing crops between rows of trees and strip cropping which alternates multiple rows or strips of one crop with another. Intercropping can also include growing fast crops with slower crops so that the faster crops can be harvested before the slow growing crops have matures. Relay cropping involves sowing a second crop before the first crops has been harvested.
A well-designed intercropping system would include the following:
Crops of different heights
Crops with deep roots along with shallow-rooted crops
Complimentary and compatible crops, such as nitrogen dependant crops followed by nitrogen fixing crops
Crops which have different weed/pest susceptibilities
