Description of the Business As Usual (BAU):
In annual crop systems, only species is sown in the same portion of land. Under conventionally managed systems, harvest residues are removed by baling or buried by ploughing.
Description of the system change:
Intercropping is the practice of growing more than one crop simultaneously on the same piece of land, that is, spatially intercropped during the same season. This creates a more similar
system to nature, where different plant species grow together, which is not usually the case on the farm.
Intercropping is established to improve the ecosystem services of the farming system. There are several objectives for intercropping such as: optimising space and resources, ensuring
better and more stable yields, improved forage quality and soil fertility (Lithourgidis et al., 2011), repelling pests, reducing weeds, providing nutrients for neighbouring plants and protecting bare soil in case of long distances between crop rows (Cong et al., 2015). Intercropping reduces weeds by limiting the “niche space” weeds need to grow (Liebman & Dyck, 1993). In addition, pest and disease pressure is reduced due to the dilution of suitable hosts (Boudreau, 2013). Tolerance in crop association must be considered in intercropping with two annual crops, as there
are species that may have a certain intolerance when they are combined. In addition, the sowing of the secondary crop must be established between rows of the main crop at an appropriate
time to avoid damage to the established crop.
Undersown crops (relay cropping) are a form of intercropping in which an auxiliary crop is sown shortly after the establishment of the main cash crop. The secondary crop is established in the interrow of the standing crop, allowing both crops to coexist spatially and temporally during part of the growing season. As a living ground cover, undersown crops provide soil protection during and after the main crop cycle while improving resource-use efficiency and enhancing agroecosystem resilience. Although they are often classified as interseeded cover crops, in this configuration, they function as a form of relay intercropping. It should be noted that undersown species established only after the harvest of the main crop are considered cover crops. In contrast, when they are sown into the inter-row of a standing crop and overlap with it in time, they are classified as relay intercropping. Therefore, undersown crops can be regarded as a form of relay intercropping whenever both spatial inter-row establishment and temporal coexistence with the main crop are present.
An additional term used in the intercropping context is ‘companion crops’, which refers to functionally complementary species grown within an intercropping system, where the primary objective of the companion crop is to provide ecosystem services rather than harvestable yield.