Effect of Rhizophagus intraradices and chemical fertilizer application on yield and yield components of safflower (Carthamus tinctorius L.) and chickpea (Cicer arietinum L.) in intercropping

Intercropping as a new green revolution can prepare the way for sustainable production by increasing resource use efficiency. In agroecosystems sustainable management, application of biofertilizers especially mycorrhiza as a supplement or alternative for chemical fertilizers is very important. Accordingly, a study was conducted to evaluate the effects of application of Rhizophagus intraradices and chemical fertilizers on yield and yield components of safflower (Carthamus tinctorius L.) and chickpea (Cicer arietinum L.) under intercropping systems.

A field experiment was carried out as factorial based on randomized complete blocks design (RCBD) with 20 treatments and three replications at the Faculty of Agriculture, University of Maragheh in 2019. The first factor including different planting patterns (P1: safflower sole cropping, P2: chickpea sole cropping, P3: cropping of a row of safflower+ a row of chickpeas, P4: cropping of three row of safflower+ two row of chickpeas, P5: cropping of four row of safflower+ two row of chickpea) and the second factor including different fertilizer sources (F1: control, F2: application of arbuscular mycorrhizal fungus (Rhizophagus intraradices), F3: recommended chemical fertilizer and F4: 50% chemical fertilizers + mycorrhiza fungus (AM).

The results showed that the highest seed yield of safflower (1906.6 kg/ha) and chickpea (765 kg/ha) were observed in monoculture with application of 50% chemical fertilizer+ mycorrhizal fungus. Furthermore, the highest of safflower oil content (28.51%) and yield (508.71 kg/ha) were obtained in planting pattern of 4:2 and monoculture with application of 50% chemical fertilizer+ mycorrhizal fungus, respectively. Although, seed yield of safflower and chickpea in monocultures decreased in compared with intercropping, but the land equivalent ratio (LER) in the all planting patterns was higher than one. So that the highest (1.89) LER was observed in planting pattern of 1:1 integrated with 50% chemical fertilizer+ mycorrhizal fungus.

Based on the land equivalent ratio, system productivity and intercropping monetary indices intercropping pattern of 1 row chickpea+ 1 row safflower with application of 50% chemical fertilizers+ mycorrhiza fungus not only leading to agricultural ecosystems diversity and sustainable productivity, but also effective in enhancing economic income and land use efficiency. As a result, application of biofertilizer in intercropping can reduce the detrimental implications of chemical fertilizers on the environment.