Chapter 2: Cereal-Legume cropping systems

Intercropping is the practice of growing two or more crops in the same area, at the same time. Crop rotation is the practice of growing different crops in the same area, in a special sequence over seasons. The cereal-legume systems comprising maize followed by legumes (common beans, soybeans, groundnuts or cowpea) are common crop rotation practices in many parts of the world.

In general, mixed cropping is better suited to farmers with small landholdings whereas crop rotation is more suitable to farmers with larger landholding. However, there are other factors such as household needs and farm economics that determine choice of these two SAI practices. The land equivalent ratio (LER) is often used to measure benefits of intercropping compared to planting a single crop (sole cropping). The LER is defined as the land required for production of the same yield in the sole crops compared with the intercrop. A LER greater than 1 indicates intercropping is advantageous to sole crops (Table 2.1).

Advantages of cereal-legume intercropping systems

Intercropping was practiced traditionally by African farmers as mixed cropping but later abandoned when high input-demanding cash crop production systems were introduced in the 1930s but now being promoted again due to their sustainability merits. The advantages and disadvantages of intercropping have been summarized in Table 2.1.

Figure 2.1 Maize intercropped with common beans

Table 2.1 Advantages and disadvantages of intercropping practice

Advantages of cereal-legume rotation systems

Crop rotation using cereal and legumes is another commonly used practice by smallholder farmers. The main advantages and disadvantages of crop rotation are presented in Table 2.2.

Table 2.2. Advantages and disadvantages of cereal-legume rotation