Introduction: Biodiversity is one of the ingredients of sustainable agriculture. As biodiversity increases or decreases, the provision of ecosystem services in the ecosystem of agricultural systems also changes. Therefore, biodiversity in the ecosystem of the agriculture system can improve by using the intercropping system and increasing the diversity of soil biological species. One of the ways to increase diversity in agricultural ecosystems is the use of several types of crops, including intercropping and the appropriate combination of soil microorganisms.The purpose of this research was to evaluate the yield and yield components in alternate intercropping of bean and maize, and to investigate the superiority of monocropping and intercropping of these two plants when using mycorrhizal fungi and rhizobium bacteria to determine the best treatment for them.
Materials and Methods: In order to investigate the effect of rhizobium bacteria and arbuscular mycorrhizal fungi on yield improvement and potassium uptake in replacement intercropping of corn and bean, a factorial experiment in a randomized complete block design with three replications, with factor 1- Rhizobium (no consumption and consumption) 2- Mycorrhizal fungus (non-consumption and consumption) and 3- intercropping system (maize, bean and intercropping) was implemented in 2019 at Payame Noor Azna University.
Results and Discussion: The results showed that the intercropping was significant for traits such as grain yield  beans and corn. The results showed that the effect of different culture systems on traits such as plant leaf chlorophyll, grain yield, biological yield, number of rows per ear, number of seeds per ear row and number of pods per plant was significant at the level of 1% probability. Also, different levels of Rhizobium bacterium consumption were significant on traits such as grain yield, biological yield of beans, chlorophyll of corn leaves and number of pods per plant. Consumption of mycorrhizal fungus on traits such as number of seeds per row, chlorophyll of corn leaves was statistically significant at the level of one percent. The results showed that the intercropping treatment with the use of rhizobium bacteria and mycorrhizal fungi increased the biological yield, leaf chlorophyll, and the number of seeds in the cob row in corn by 47, 55, 26, and 39%, respectively, compared to the control treatment. Also, the treatment of monocropping bean with bacteria increased the seed yield, biological yield, and chlorophyll of bean leaves by 50, 47, and 36%, respectively, compared to the control treatment.
According to the obtained results, the land equality ratio in all intercropping treatments was more than one and also the highest land equality ratio was obtained from the intercropping treatment with the use of Rhizobium bacteria and Mycorrhizal fungus equal to 1.98. Which shows the positive correlations between intercropping plant members compared to monocropping and shows the superiority of corn intercropping over monocropping.
Conclusion: The land equality ratio of more than one in intercropping can attribute to nitrogen fixation and nitrogen uptake in intercropping. When two species grow nearby, both species compete for water and nutrients. The presence of nitrogen-fixing nodes as a source of nitrogen supply in bean reduces competitive pressure. In general, according to the results of this experiment, it can be expected that with a suitable combination of biofertilizers and mixed cultivation, the biofixation of nitrogen and the absorption of other nutrients will be improved, and finally, it will increase the yield and stability.