Where we work


The Sustainable Intensification of Maize-Legume Cropping Systems for Food Security in Eastern and Southern Africa (SIMLESA) is working in Ethiopia , East Africa, because of the country’s large population of approximately 96 million people (World Fact Book, 2015)1 , and high poverty levels2 as a result of recurrent famines, aggravated by small farm sizes, frequent droughts and extensive land degradation. The potential for improving productivity and incomes for farmers who depend on maize and legume systems, however, remains pitifully high. In this country, 1.99 million hectares is planted to maize yielding approximately 3.243 tons per hectare, but with very high variability which increases the risk of seasonal food insecurity. Likewise, the legume area is expanding4 in response to growing export demand for legumes – for example, haricot beans to East Africa, and Sudan. However, less than 25 percent of the maize or legume area is under improved varieties but underdeveloped seed systems are a major constraint.

Other constrains to agricultural production and productivity are low level of technology adoption, poor market access for smallholder farmers, and limited technological options for the very diverse5 agro-ecological areas and farmers’ circumstances. Resource shortages, including scarcity of land in high potential areas6, seasonal labour shortage, inadequate draught power, and insufficient supply of input and credit are identified as major crop production challenges. Also, population pressure is another constraint contributing to environmental degradation and declining land holding per household. Farmers in drought-prone areas have an average farm size of 2.36 hectares and average family size of eight people per household. On the other hand, average farm size in sub-humid maize-legume based farming system is 1.5 hectares with average family size of seven per household. Cognizant of these inter related production constraints of the predominantly maize-legume farming systems, Ethiopia was identified a major SIMLESA program country by ACIAR and CIMMYT.

SIMLESA activities are being implemented by eight research canters including 17 districts/communities located in different maize-legume growing agro-ecologies of the country.

In the sub-humid high potential maize and legume growing farming systems, low soil fertility, especially low nitrogen, is the most important production constraint. Use of traditional soil fertility management practices such as crop residues, manure, fallow, cereals/legume intercropping, crop rotation, among other practices, has declined together with farm size, coupled with alternative uses for manure as fuel and crop residues as feed, fuel and construction material. Few farmers practice fallowing and crop rotation because of scarcity of land. With increasing population pressure, and land scarcity, livestock increasingly dependent on crop residues; production of improved forage or fodder crops is hampered by poor awareness of available options and lack of seed.

  1. https://www.cia.gov/library/publications/the-world-factbook/geos/et.html
  2. 39% of the population is below poverty line
  3. The Federal Democratic Republic of Ethiopia Central Statistical Agency Agricultural Sample Survey 2013/14
  4. The areas of pulses was 2.37 ha in 2010 while was 3.26 in 2014.


Forty-six percent of Kenya’s population of approximately 40 million people live below the poverty line. However, there are regional disparities. About 59 percent of the population in the western highlands falls below the poverty line compared to 31 percent in the central highlands. Kenya has 1.6 million hectares of maize with an average yield of 1.8 tons per hectare, and a great need for recently developed stress tolerant varieties because of the heterogeneity of maize and legume production environments, including large areas of low rainfall semi-arid crop land. Soil degradation and erosion are also widespread. Agricultural research in Kenya started during the early years of the last century. For instance, coffee research started in 1908. The first hybrid maize variety was released in 1964. Since then, several maize and legume varieties and their accompanying agronomic practices have been generated by the agricultural research system in the country.

The main challenge to agricultural productivity in Kenya is the low adoption of improved agricultural technologies. Farmer access to markets for key inputs such as seed and fertilizer, high transaction costs in marketing surplus produce also undermine incentives for technology adoption. Low amounts of soil organic matter combined with poor land cover have resulted in poor soil structure, limited rooting depth and susceptibility to accelerated erosion and low nutrient retention capacity. The situation is exacerbated by the high level of production risk mainly due to high inter and intra season fluctuations in rainfall. Much of the rainfall comes in few high intensity events with long dry spells in between. This results in high frequency of occurrence of agricultural droughts that reduce yield of rain fed agriculture.

The main effort of research work in Kenya by SIMLESA was to increase maize-legume cropping system productivity by at least 30 percent and reduce the downside risk by the same percentage in a decade from the start of the program in 2010. Implementation of the study was possible due to participation of at least seven partners led by the Kenya Agricultural and Livestock Research Organization (KALRO) – Embu (eastern) and KALRO – Kakamega (western) scientists. The other partners were exploratory trial farmers (24 farmers in either region), farmer groups, local innovation platforms (LIPs), Ministry of Agriculture extension staff, seed companies, crop insurers, CIMMYT scientists and other research programs in the regions.

In attempting to resolve the problem, SIMLESA pioneered the establishment of innovation platform (IP) that was instrumental in addressing the compelling research agenda of testing and promoting appropriate soil fertility management and maize-bean intercrop systems under CA practices. Eight local innovation platforms were formed in the eight program sites and focused on working and bringing partners along maize-legume value chains. At the end of 2014, the program was involving more than 30 different partners in the country particularly in scaling out SIMLESA CA-based portfolios.


Malawi is heavily dependent on some 1-2 million hectares of maize with average yields (2.6 tons per hectare) that have been boosted recently by strong Government-led support programs. Seasonal variability is high depending on rainfall and fertilizer availability.

Maize is the main staple food in Malawi. Over 90 percent of the total cultivated area is planted to maize, mostly by resource poor smallholder farmers. Malawi consumes about 170 kg maize per capita/year which constitutes more than two thirds of the caloric consumption, the highest proportion in the world. The continuous cropping of maize has led to mining of soil nutrients and declining soil fertility. Together with small farm size, soil degradation and erosion continue to be serious threats to future productivity.

Grain legumes form an important component of Malawi’s maize-based farming systems. Beans and pigeon pea, for example, are mostly intercropped with maize and other cereal crops. Maize and pigeon pea intercropping is a common practice especially in southern Malawi where average land-holdings are small. Both maize and pigeon pea are grown on ridges which are generally spaced 90 cm apart, with 75-90 cm between plants on the ridge. However, the current recommendation of planting maize and pigeon pea in association is for long duration pigeon pea types which flower and produce pods after the maize harvest providing little competition to the companion maize crop. New shorter season pigeon pea varieties may need different planting patterns. A pure stand is currently recommended for groundnut production in maize-groundnut rotations. However, alternatives for groundnut-maize systems need to be identified because of increasing population pressure and reduction in farm size. The same applies to soy beans which are currently produced in maize-soy bean rotations.

Most smallholder farming in Malawi focuses on producing staple food crops, such as maize, for home consumption. The smallholder sector remains largely unprofitable and is characterized by low uptake of improved inputs and technologies, poor quality control, weak links to markets, high transport costs, and lack of access to finance and credit. To increase production, incomes and employment opportunities, and to move from subsistence to commercial farming, these issues need to be addressed effectively.

Since agriculture plays a dominant role in Malawi’s economy, conservation agriculture — which aims for the sustainable and profitable farming based on three principles of minimal soil disturbance, permanent soil cover and crop rotation – is one key strategy to help reduce poverty and to enhance climate resilience, in addition to increased agricultural productivity.

Capitalizing on the strong policy support, the integrated technology and value chain interventions of the program are expected to enhance productivity and food security which may also provide useful lessons for other countries in the region. However, being land locked with high population density and facing intense depletion of soil nutrients, the cost of fertilizer inputs are particularly high and therefore the role of legumes in maintaining soil fertility and increasing maize and legume yields is important.

CIMMYT’s SIMLESA program, is using conservation-agriculture-based systems in six districts of central Malawi, namely Kasungu, Mchinji and Lilongwe in the mid-altitude agroecology; and Balaka, Ntcheu and Salima in the lowlands agroecology as shown by the map below. Following the successful implementation of the first phase, CIMMYT is implementing the second phase of SIMLESA from 2014 to 2018, with an increased focus on upscaling the sustainable intensification technologies initiated and tested in the first phase.


At the planning stages of the SIMLESA program, Mozambique had a substantial area of maize (1.4 million hectares), producing 1.2 million tons – a very low average yield (0.85 tons per hectare in 2007) with high variability. Despite having ample land, soil fertility is low. The south of the country is semi-arid, research and extension capacity and infrastructure is weak while household food security and poverty were rampant. Frequent droughts and floods, use of unimproved varieties, lack of access to fertilizers and use of unsustainable soil management practices coupled with dysfunctional agricultural markets all impact negatively on agricultural productivity and hence the need for SIMLESA interventions in Mozambique. In Mozambique, as in the other countries, legumes play important roles. Grain legumes, particularly cowpea in the medium to lowlands, are an important source of protein for the country’s smallholder farmers. Soybean is emerging as an important raw material for export and poultry particularly in Central and Northern provinces of Manica and Nampula, where there is a growing demand for feed, particularly for the poultry industry. Pigeon pea is mainly grown in the central provinces of Manica, Tete and Zambézia and the southern province of Inhambane. SIMLESA prioritized three provinces of Central Mozambique (Manica, Tete and Sofala) for implementation of activities given the food security issues in these provinces.


Agriculture in Tanzania employs 84 percent of the rural population. For many years, agricultural production of smallholder farmers has generally been low, due to low soil fertility, erratic and unreliable rainfall and poor agricultural production techniques. Drought and low soil fertility ranks high among the factors limiting crop production in sub-Saharan Africa. Current climate change and soil mining practices have exacerbated the situation to the extent that yields are now as low as 1-2 tons of maize per hectare and 0.5 tons of pigeon pea per hectare.

The area under maize production in Tanzania is 3.0 million hectares. Maize is an important food and cash crop in the country. Over 80 percent of the population depends on maize with per capita consumption of around 100 kilograms per year. The crop occupies more that 40 percent of the total cultivated area and accounts for up to 61 percent of the total calories in the diets as well as 50 percent of utilizable protein for the majority of Tanzanians. The national average yield is about 1.2 tons per hectare compared to an average potential yield of 4.5 tons per hectare. The main constraints facing the Tanzanian maize sub-sector are low productivity caused by use of unimproved seeds, poor agronomic practices, diseases, insects, low soil fertility, moisture stress, and weeds especially Striga. Socioeconomic constraints include unreliable input and output markets, lack of credit facilities, poor infrastructure, unaffordable and/or low quality inputs.

Maize cropping systems in Tanzania are characterized by maize mono-cropping (about 30 percent) and intercropping of maize and legumes (about 70 percent). The maize/pigeon pea/beans system is common in the northern and eastern zones while maize/cowpea/ bean system is dominant in Lake and Western zones. Maize/mucuna cover crop system is also practiced in the northern zone.

The Selian Agricultural Research Institute (SARI) and Agricultural Research Institute (ARI) Ilonga are the Ministry of Agriculture, Food Security and Cooperatives under the Department of Research and Development (MAFC-DRD) institutions implementing SIMLESA program in Tanzania. While SARI is located in Northern Tanzania with the mandate of carrying out research in major food crops including cereals and legumes, farming systems and soils; ARI-Ilonga is located in the Eastern Zone with the mandate of carrying out research in food crops suitable for medium and low altitude areas.

The SIMLESA program aims at improving productivity in maize and legume farming systems through understanding of social and economic factors influencing productivity, demonstration of the proper agronomic practices and climatic resilience production systems, for example, conservation agriculture through innovation systems, breeding of improved varieties and scaling out of the best farmer preferred SIMLESA options. During the past six years, the SIMLESA program was implemented in 12 communities spread in different agro-ecologies in northern and eastern Tanzania.

SIMLESA target and spill over countries

SIMLESA Target and spill over countries

Funded by

Ethiopia Kenya Malawi Mozambique Tanzania
© Copyright. CIMMYT is supported by the Consultative Group on International Agricultural Research (CGIAR)
Sustainable Intensification of Maize-Legume Systems for Food Security in Eastern and Southern Africa (SIMLESA)

International Maize and Wheat Improvement Center (CIMMYT)
P.O. Box MP 163,
Mount Pleasant Harare, Zimbabwe
Phone numbers in Zimbabwe:
+263 (772) 465 211/212
Fax: +263 (4) 301 327