Evaluation of Production Potential, Resources Use Efficiency, and Economical-Ecological Benefits of Bean (Phaseolus vulgaris L.) Intercropped with Pepo (Cucurbita pepo L.) using Mycorrhiza

Introduction

Demand for food in the world is likely to be nearly two times the current level by 2030, while the amount of new land for cultivating area is very limited (Marzban et al., 2014). Therefore, the design and implementation of systems with stability and performance are highly felt (Hosseini et al., 2016). In agriculture, there are different perspectives for imitation of nature, one example of which is sustainable agriculture. Intercropping is defined as a sustainable agricultural operation in which two or more species grow simultaneously during a season on a piece of land (Amani Machiani et al., 2018). By the way, the use of bio-fertilizers is a method to revive the natural flora of the soil and it is considered as a path to sustainable agriculture (Baqual & Das, 2006). Unfortunately, most conventional agricultural systems based on the high consumption of chemical fertilizers, are deprived of the benefits of coexistence of useful microorganisms with the plant, such as mycorrhiza coexistence. Therefore, it seems that using the intercropping and bio-fertilizer inoculation can be an effective step towards sustainable production in the agricultural lands.

The experiment was conducted as factorial mode based on a randomized complete block design with three replications at the research farm of the Faculty of Agriculture, Bu-Ali Sina University. Using and non-using of mycorrhiza and 5 cultivation patterns including the pure crop of pumpkin, pure bean cultivation and additive intercropping of 20, 40 and 60% beans with pumpkin were the experimental treatments. The cultivation of both species was carried out on 9.3.2017. At the end of the growth period, harvest was done from each plot after removing the marginal effect, and oil percentage, oil yield, Pepo equivalent yield )PEY(, water use efficiency (WUE) and nitrogen utilization efficiency (NUE), the percentage of root clonization, as well as the usefulness indices of the intercropping were measured. The data were analyzed by SAS9.1 and the means were compared using LSD test at a probability level of 5%.

The results indicated that the effect of crop pattern in both application and non-application of mycorrhiza were significant on the number of fruits per plant, seed weight, seed yield, oil yield, equivalent yield, water use efficiency and nitrogen use efficiency in pumpkin, as well as number of pods per plant, the weight of 100 seeds and grain yield of the bean. The percentage of oil in pumpkin and the percentage of root clonization in both plants were also significant in the case of mycorrhiza application. The highest amount of pumpkin equivalent yield, water use efficiency, and nitrogen use efficiency were obtained from additive intercropping of 40% bean with pumpkin under mycorrhiza application. The partial land equivalent ratio in the pumpkin was higher than that of bean, which can be concluded that the pumpkin cropping is influenced positively by the intercropping with the bean. The highest values of land equivalent ratio (LER(, relative value total )RVT( and Cumulativerelative efficiency index )REIc( were obtained from 40% bean incropped with pumpkin treatment. According to the results of CC, CR, and AG, it can be concluded that the bean is suitable for intercropping with pumpkin. ATER values of more than 1 were obtained in all treatments, except for the additive intercropping of 60% bean with pumpkin in both application and non-application of mycorrhiza. The highest amount of LUE and SPI in the case of application and non-application of mycorrhiza were obtained from additive intercropping of 40 and 20% bean with pumpkin, respectively, indicating the ability of the mycorrhiza to modify the competition of pumpkin with beans.

According to the results of this study it was indicated that in the case of mycorrhiza application, the amount of all traits in the same treatments increased, and the 40% bean intercropped with pumpkin together with the application of mycorrhiza was determined as the superior treatment, which could be considered for the sustainable agriculture development and maintaining the ecosystem health.