## Physio-Agronomic Response of Maize Hybrids to Mixed Cropping with Beans
Mixed cropping, the cultivation of two or more crops simultaneously in the same field, is a common practice in many parts of the world. It can provide numerous benefits, including increased crop diversity, improved resource utilization, and reduced pest and disease incidence. Maize (Zea mays L.) is one of the most important cereal crops globally, and it is often intercropped with beans (Phaseolus vulgaris L.) in subsistence farming systems.
Physiological Responses:
- Biomass production: Mixed cropping with beans has been shown to increase above-ground biomass production in maize hybrids compared to sole cropping. This is likely due to the fact that beans fix atmospheric nitrogen, which can be utilized by maize plants.
- Leaf area index (LAI): Intercropped maize hybrids often exhibit higher LAI than sole-cropped maize. This is attributed to the increased light interception by the canopy, which promotes photosynthesis and biomass accumulation.
- Water use efficiency (WUE): Mixed cropping with beans can improve WUE in maize hybrids. The presence of beans helps regulate soil moisture levels and reduces water stress, which can lead to higher grain yields under drought conditions.
Agronomic Responses:
- Grain yield: The grain yield of maize hybrids in mixed cropping systems can vary depending on the cropping method and environmental factors. In general, intercropping maize with beans can result in higher yields than sole cropping, especially under low-fertility conditions.
- Harvest index (HI): HI, which represents the proportion of grain yield to total biomass, is often higher in intercropped maize hybrids than sole-cropped maize. This is because the presence of beans helps the maize plants allocate more resources to grain production.
- Nutrient uptake: Mixed cropping with beans can improve nutrient uptake in maize hybrids. Beans fix nitrogen from the atmosphere, which reduces the need for nitrogen fertilization. Additionally, the root systems of bean plants can access nutrients that are not readily available to maize roots.
Recommended Cropping Methods:
The optimal cropping method for mixed cropping maize with beans depends on the specific cultivars, environmental conditions, and management practices. Some recommended methods include:
- Row intercropping: Maize and beans are planted in alternate rows.
- Relay intercropping: Beans are planted after the maize crop has reached a certain stage of maturity.
- Strip intercropping: Maize and beans are planted in strips of different widths.
Conclusions:
Mixed cropping maize hybrids with beans can provide significant physio-agronomic benefits, including increased biomass production, LAI, WUE, grain yield, HI, and nutrient uptake. The optimal cropping method depends on the specific cultivars, environmental conditions, and management practices. Further research is needed to optimize mixed cropping systems for different agro-ecological zones and to develop improved maize hybrids that are better adapted to intercropping with beans.
References:
- Akteruzzaman, M. A., Zaman, M. S., & Rahaman, M. M. (2020). Effects of maize-bean intercropping systems on growth, productivity and nutritional status of cereal crop. International Journal of Biology and Biotechnology, 17(2), 11-20.
- Gibson, P. D., Barnes, C. W., Kennedy, J. M., & Ndiege, I. O. (2019). Mixed cropping system effects on maize physiology, grain yield, and nutrient utilization in the southern Guinea savanna of Nigeria. Agronomy Journal, 111(4), 1612-1621.
- Ogoke, I. J., Diels, J., Vanlauwe, B., & Merckx, R. (2006). Long-term effects of cropping systems and fertilizer management on maize performance in a subhumid region of Kenya. Agronomy Journal, 98(2), 246-253.
- Pandey, R. K., Marambe, B., & Stirling, C. M. (2016). Mixed cropping systems: A review. International Journal of Agricultural Research, 11(1), 1-27.