Chapters 2.15
2.15 - Intercropping Maize and Common Bean
Veronica Treble, University of Guelph,Canada
Suggested citation for this chapter.
Treble,V. (2022) Intercropping Maize and Common Bean . In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org
Introduction to Intercropping Maize and Common Bean
Intercropping is a method of farming where two or more types of crops are planted in the same field. Intercropping improves soils, helps prevent pests, and allows for positive crop interactions to increase the yield of all crops. Maize is considered an important cereal crop around the world. Maize contains mostly starch (72%) along with fat (4%) and protein (10%) (Anane et al., 2019). Maize can be intercropped with legumes such as common bean to improve its quality and yield. Legumes are nitrogen fixing crops, meaning that they form a symbiotic relationship with bacteria that convert atmospheric nitrogen gas into organic nitrogen fertilizer. When planted with maize, legumes can therefore add nitrogen to soil which benefits maize. The beans also suppress weeds. The following outlines the benefits, challenges, costs as well as tips to get started when it come to intercropping maize and common bean.
How to Intercrop Maize and Common Bean
Overview of different types of intercropping:
There are commonly four types of intercropping: strip, row, relay, and mixed (Mousavi and Eskandari, 2011). Intercropping, as seen in Figure 1, is when two or more types of crops are grown in alternating rows (Mousavi and Eskandari, 2011). The rows can also be randomly arranged with no distinct pattern. Each row has one type of crop with a second type of crop in the next row and so on. Mixed intercropping is similar except two or more crops are planted without row arrangement meaning there can be multiple types of crops in the same row (Mousavi and Eskandari, 2011). With strip intercropping, crops are also grown in rows, except the rows are spaced far enough that separate cultivation is possible, but the different crops still can interact and benefit each other (Mousavi and Eskandari, 2011). Relay intercropping, the final type of intercropping, is when the second crop is planted while the first crop is later in its growing cycle. When the first crop is in its reproductive stage, the second crop can be planted (Mousavi and Eskandari, 2011). Any of these methods can be applied to intercropping maize and common bean. However, row or mixed intercropping seems to be the most common method.
Figure 1. Row Intercropping (Sergieieva, 2023).
Intercropping requires strategic placement, crop density, timing and harvesting (Yayeh et al., 2021). The majority of studies conducted on intercropping maize and common bean use row or mixed intercropping, where common beans are planted between rows of maize, or in the same row. Some studies found that a delay in planting the second crop can benefit the main crop (Alemayehu et al.,2017). A study found that when common bean was planted four weeks after the maize emerged, the height of the maize was increased, however, when common bean was planted six weeks after the maize emerged, the maize grain output was maximized even though the plant size was reduced (Alemayehu et al.,2017). Measuring how spaced different crops are planted is important as positive interactions are desired, but not competition or interference (Finley and Ryan, 2018). Typically, maize and common bean crops are spaced around 10 cm apart, with 40 cm of space left between rows (Nassary et al., 2020). A study conducted in Ethiopia concluded that spacing maize and common bean plants at 8.9 cm apart increased overall yield by 42% (Habte et al., 2016). The economic advantage could also be maximized with a density of 93750/ha which could be achieved by planting at 8.9 cm apart (Habte et al.,2016).
Another method Is to measure other ways the selected crops can interact, such as root growth (Finley and Ryan, 2018). Typically, planting two or more crops that grow their roots to different depths limits competition (Finley and Ryan, 2018). When the roots stretch to different depths, they have access to resources and nutrients at different depths, therefore, two different plants are not “fighting” over these resources. Maize grows roots deeper into the ground whereas common bean has very shallow growing roots (Alemayehu et al., 2017). A problem can occur when one of the crops that are intercropped is more competitive and better able to survive than another as the weaker crop will become overtaken (Finley and Ryan, 2018). It is important to select crops that are similarly competitive for the best results (Finley and Ryan, 2018).
Benefits of Intercropping Maize with Bean
Farms can benefit from intercropping common bean with their maize as they are able to plant at a higher density on a small land area, therefore increasing the overall yield. Studies found that a maximized seed yield was obtained when a full field of maize was intercropped with 75% common bean (Habte et al., 2016). The seed yield was measured at 1413 kg/ha (Habte et al., 2016). This yield was mainly due to the increased planting density (Habte et al., 2016).
Many farms use nitrogen fertilizer to improve the growth of their crops, however, this fertilizer is becoming unaffordable to smallholder farms. Intercropping with common bean limits the need for nitrogen fertilizer as common beans are able to fix their own nitrogen from the atmosphere (Massawe et al., 2016). It is found that nitrogen fertilizer should not be used on a field where maize is intercropped with common bean because the common bean will use the fertilizer rather than fixing their own nitrogen which will create competition with the maize crops (Massawe et al., 2016). Maize is one of the world’s most important cereal crops used in human and livestock diets as it is very starchy (74% starch), but it lacks some critical amino acids in the grain (with only 10% protein content)(Anane et al., 2019). Common bean is one of the most important legumes worldwide as it is rich in protein, including some of the amino acids that are deficient in maize, as well as containing other nutrients (Nassary et al., 2020). Common bean is used in human and livestock diets, making this crop very beneficial for smallholder farms (Nassary et al., 2020). Therefore, intercropping maize with common bean provides smallholder farms with both of these very important crops.Intercropping maize and common bean also helps to ensure that a field will not be entirely wiped out by pests or other natural causes (Nassary et al., 2020). This is important for smallholder farms as these farmers completely rely on their crops to support their families. Specifically, intercropping helps to deter insects or pests that are a threat to crops (Mohler and Stoner, 2009). This is because pests or insects often attack one crop, but when there are multiple crops, pests are less able to populate in a field.
Main Goals of Intercropping Maize and Common Bean
The primary goal of intercropping maize with common bean is to maximize the quality of maize while maximizing the yield of the entire field (Nassary et al., 2020). While there are little benefits for the common bean crop (except if they are pole beans that use the maize stalk as a scaffold to grow upwards to capture sunlight), the common bean is still harvested and sold for additional profit (Nassary et al., 2020).
Challenges With Intercropping Maize with Bean
Studies found that the yield of common bean was lower when intercropped with maize, which is most likely due to the shading caused by the maize crops (Habte et al.,2016). A study showed that when intercropped with maize, the seed yield of common bean was found to be 734.2 kg/ha, but when planted alone, the yield was significantly higher at 1365.5 kg/ha (Habte et al.,2016). Though this shows a significant decrease in yield, the overall yield including from maize is still maximized (Habte et al.,2016). Another challenge with intercropping maize with common bean is the ability to use herbicides on crops (Massawe et al., 2016). Herbicides are often used on maize crops to prevent pests and weeds, however some of these herbicides may be harmful to common bean plants (Massawe et al., 2016). Though this may be a challenge, intercropping is found to reduce the overall population of pests or weeds in a field, therefore chemical may not be needed (Mohler and Stoner, 2009). While intercropping is very beneficial in some ways, it also requires a lot of labor. Intercropping also requires a lot of planning and access to knowledge as it requires strategic timing and placement (Yayeh et al., 2021).
Cost Benefit Analysis
A cost benefit analysis was done in Ethiopia to measure the gross revenue and net value benefits from intercropping maize with common bean. This cost benefit analysis was recorded in Ethiopian currency (Birr). One Birr is equivalent to 0.018 U.S. dollars. This study showed that maize planted alone had a net benefit and gross value of 89,221.5 birr/ha (Wakweya et al., 2021). When maize was intercropped with common bean, the net benefit and gross value was increased to 99,519 birr/ha (Wakweya et al., 2021). When calculated, the gross value and net benefit was 10,297.5 birr/ha higher when maize was intercropped with common bean compared to when maize was planted alone (Wakweya et al., 2021). Since intercropping does require more labor and equipment, there were additional costs. The cost to intercrop maize with common bean was 4,061.25 birr/ha more than if maize was planted alone (Wakweya et al., 2021). When these additional costs were compared to the gross value and net benefit difference between planting maize alone and intercropping, the income was still higher when maize was intercropped with common bean (Wakweya et al., 2021). Overall, this study found a yield increase of 10.4% when maize was intercropped with common bean compared to when maize was planted alone (Wakweya et al., 2021). Therefore, intercropping common bean with maize is a good way to increase income for smallholder farms.
Conclusion
To conclude, even though intercropping maize with common bean may be expensive, labor intensive and does not necessarily benefit the yield of common beans, it is still an excellent farming method for smallholder farmers to adopt. Intercropping maize with common beans increases the overall yield of the entire field because of overall increased density. Common beans are an excellent intercrop because of their nitrogen fixing abilities, which greatly benefits the quality of maize. It is also excellent for smallholder farms to have both these crops on their farm since maize is an important starchy cereal and common bean is rich in protein. Overall, intercropping maize with common bean, generating a greater income than maize alone and having many additional benefits, would be a beneficial method for smallholder farms but it does require access to knowledge extension services.
Practical Links to Get Started
Guidelines for Intercropping - SARE – downloadable manual with guidelines for intercropping and crop rotation.
Practical intercropping (youtube.com) – shows how to check soil, talks about methods and steps to intercropping (how they did it) and harvesting.
The Magic of intercropping Maize 🌽 and Beans. You need to try this method. (youtube.com) – farmer shows how he has intercropped maize with beans.
Mixed Maize and Beans Farming (youtube.com) - has some good information on spacing and weeding. Also talks a bit about herbicides and fertilisers.
References
1. Alemayehu, D., Shumi, D., & Afeta, T. (2017). Effect of Variety and Time of Intercropping of Common Bean (Phaseolus vulgaris L.) With Maize (Zea mays L.) on Yield Components and Yields of Associated Crops and Productivity of the System at Mid-Land of Guji, Southern Ethiopia. European Journal of Agronomy 113:125964 https://www.researchgate.net/publication/338972554_Productivity_of_intercropping_with_maize_and_common_bean_over_five_cropping_seasons_on_smallholder_farms_of_Tanzania
2. Anane, P.-S., Du, Y., Wang, T. Y., Huang, Z. Y., Bai, Y. C., Asiedu, M. A., & Liu, S. X. (2020). Cost and benefit analysis of organic mulching and intercropping in maize cultivation. Applied Ecology and Environmental Research, 18(6), 7795–7812. https://doi.org/10.15666/aeer/1806_77957812
3. Arsyad, M., Sabang, Y., Agus, N., Bulkis, S., & Kawamura, Y. (2020.). Intercropping farming system and farmers income. AGRIVITA Journal of Agricultural Science. 42(2): 360-366 https://agrivita.ub.ac.id/index.php/agrivita/article/view/2724/1271
4. Bitew, Y. et al. (2022). Response of Maize and Common Bean to Spatial and Temporal Differentiation in Maize-Common Bean Intercropping. PLoS One 16(10), e0257203. https://doi.org/10.1371/journal.pone.0257203.
5. Bybee-Finley, K. A., & Ryan, M. R. (2018). Advancing intercropping research and practices in industrialized agricultural landscapes. Agriculture 2018, 8(6), 80. https://doi.org/10.3390/agriculture8060080
6. Habte, A., Kassa, M., & Sisay, A. (2016). Maize (Zea mays L.)-Common Bean (Phaseolus vulgaris L.) Intercropping Response to Population Density of Component Crop in Wolaita Zone Southern Ethiopia. Journal of Natural Sciences Research, 6, 69–74.
7. Latati, M., Aouiche, A., Tellah, S., Laribi, A., Benlahrech, S., Kaci, G., Ouarem, F., & Ounane, S. M. (2017). Intercropping maize and common bean enhances microbial carbon and nitrogen availability in low phosphorus soil under Mediterranean conditions. European Journal of Soil Biology, 80, 9–18. https://doi.org/10.1016/j.ejsobi.2017.03.003
8. Massawe, P. I., Mtei, K. M., Munishi, L. K., & Ndakidemi, P. A. (2016). Improving soil fertility and crops yield through maize-legumes (common bean and Dolichos Lablab) intercropping systems. Journal of Agricultural Science, 8(12), 148. https://doi.org/10.5539/jas.v8n12p148
9. Mohler, C. L. L., & Stoner, K. A. (2022, February 7). Guidelines for intercropping. SARE. https://www.sare.org/publications/crop-rotation-on-organic-farms/guidelines-for-intercropping/
10. Mousavi, S. R., & Eskandari, H. (2011). A General Overview on Intercropping and Its Advantages in Sustainable Agriculture. Journal of Applied Environmental and Biological Sciences. 1(11) 482-486,
11. Nassary, E. K., Baijukya, F., & Ndakidemi, P. A. (2020). Assessing the productivity of common bean in intercrop with maize across agro-ecological zones of smallholder farms in the northern highlands of Tanzania. Agriculture 2020, 10(4), 117. https://doi.org/10.3390/agriculture10040117
14. Sergieieva, K. (2023, October 30). Intercropping: Types and how to benefit from the practice. EOS Data Analytics. https://eos.com/blog/intercropping/
15. Wakweya, K., Tilahun, A., Megersa, A., Tolesa, D., & Kebede, D. (2021). Contribution of Maize-Common Bean intercropping for Food and Nutrition Security in Productive Safety Net Programme Areas. Innovations for Food and Livelihood Security, 13–19. https://doi.org/Microsoft Word - REALISE-Book 4-Final.