Combined application of mycorrhizae and phosphorus fertilizer on – morpho-physiological characteristics in Quinoa (Chenopodium Quinoa Willd.) and Maize (Zea Maize L.) under intercropping system

The utilization of arbuscular mycorrhizal fungi (AMF) and phosphorus fertilizer can improve growth and physiological characteristics in plants. This study evaluated the effects of AMF and phosphorus levels on morpho-physiological characteristics of Quinoa and Maize under intercropping systems. The experiments were conducted at two locations, with three levels of phosphorus fertilizer [0 (P1), 50 kg ha−1 (P2), and 100 kg ha−1 (P3)], and AMF at two levels [inoculation M (+) and non-inoculation M (-)]. The results showed that the highest amounts of chlorophyll a (2.205/4.74 mg g−1 FW), chlorophyll b (0.75/2.88 mg g−1 FW), total chlorophyll (3.5/8.28 mg g−1), were achieved in a 50:50 intercropping ratio of Maize and Quinoa, under M (+) and P2 application. The results showed that the highest seed yield of Quinoa (2542 kg ha−1) was obtained under mycorrhizal and 50 kg ha−1 phosphorus application in the Shahrood location. Additionally, the highest total dry weight (TDW) in Maize (418.85 g m−2) was achieved with M (+), while the highest TDW of Quinoa (295.65 g m−2) was obtained in solo culture. The highest leaf area index (LAI) of Maize was obtained for sole culture, use of phosphorus 50 kg ha—1, and M (+). The highest Quinoa LAI was obtained in different cropping ratios, with the highest value of 8.52 in 50% Quinoa. The net assimilation rate in Quinoa reached the maximum (7.2 g m−2 day−1) at 45 days after sowing, while in Maize, the maximum of NAR (10.2 g m−2 day−1) was reached at 75 days after sowing. The mean comparison of traits revealed that the highest Quinoa colonization (46.29%) was achieved with a 25% Quinoa and 75% Maize cropping ratio, and a phosphorus concentration of 50 kg ha−1, using arbuscular mycorrhizal fungi (AMF). These findings suggest that AMF application in an intercropping ratio of 50:50 may be proposed to farmers as an eco-friendly approach to achieve desirable physiological characteristics.