Cropping Systems. In Malawi, over 90% of the rural Malawian population depends on rainfed agriculture for food security and livelihood. Rainfall distribution is unimodal starting in November or December to March/April. A majority of farmers are smallholders with average land holding size ranging from <1 hectare in the southern region to 1.5 hectares in northern Malawi. Cropping systems are dominated by maize, the staple food, occupying over 70% of arable land (Alwang and Xxxxxx, 1999), legumes occupy 10-15% of arable land. Examples of cropping systems include monocropping (one crop in a field), intercropping (two or more crops on same piece of land), crop rotation, agroforestry (trees with pastures or crops). Types of intercropping include row intercropping, strip intercropping, mixed cropping and relay cropping. Successful intercropping requires selection of component crops with complimentary characteristics below and above ground, and proper management practices (Xxxxxxxxx-Xxxxxxx et al., 2007). Productivity of cropping system depends on the genotypes, environmental resources (e.g. soil characteristics, climate factors, moisture gradients, pests) and management practices. Cropping systems based on ecological principles provide diversified ecosystem services. Some of the ecological principles for sustainable agricultural systems include biodiversity of plant species, integrated pest management, and socio-economic dimensions of production (Altiei, 1999; Xxxxx, 2008). The main cropping systems for maize are sole, intercrop or rotation with leguminous crops. Other major crops grown are groundnut, pigeonpea, soybean, common bean, cowpea, sweet potatoes and cassava. Balaka district is predominantly a low altitude area with short and erratic rainfall. Ntcheu district, on the other hand, has a blend of low and mid-altitude landscapes, resulting in some areas experiencing higher rainfall and cooler climate. The national crop estimates, which records the crop areas and yields, does not segregate sole and mixed cropping systems (MoAFS, 2007; MoAIWD, 2012). Crops commonly grown in both districts include maize, sorghum, cassava, pigeonpea, cowpea, sweet potatoes, soybean, groundnuts, dolichos beans and ground beans. (MoAFS, 2007; MoAIWD, 2012). Where the rains are short and erratic, cropping systems include short season varieties and mixtures and patterns that hedge against crop failure. In Malawi, nearly all crops are planted on ridges, with the spacing of most crops being aligned to...
