Evaluation of land productivity, competition and insect diversity in different intercropping patterns of sunflower (Helianthus annuus L.) and soybean (Glycine max L.) under low-input condition

Intercropping is a sustainable practice to achieve higher production with the aim to limit external inputs. A field experiment was conducted at the research farm of the Faculty of Agriculture, University of Maragheh, Maragheh, Iran, during ۲۰۱۶ growing seasons with ten treatments to evaluate the yield, analyze the competition and insect’s assemblages in sunflower (as main plant)/soybean (as companion plant) intercropping. Treatments included sunflower sole cropping, soybean sole cropping, replacing intercropping sunflower with soybean (۵۰:۵۰, ۳۴:۶۶, ۶۶:۳۴, ۴۰:۶۰, ۶۰:۴۰, ۲۵:۷۵) and additive intercropping of two plants (۱۰۰:۵۰ and ۱۰۰:۱۰۰%). Results showed that the highest sunflower grain yield (۲۷۵ g m-۲) was obtained in sunflower monoculture that was not significantly different with intercropping ratios of ۲۵:۷۵ and ۶۰:۴۰. Also, the highest and lowest grain yield of soybean was achieved in soybean monoculture (۱۳۰.۱ g m-۲) and ratio of ۱۰۰:۵۰ (۴۸.۵ g m-۲), respectively. The highest land equivalent ratio, monetary advantage index and intercropping advantage value was obtained in intercropping ratio of ۲۵:۷۵. Moreover, in all cropping patterns the aggressivity (A) and crowding ratio (CR) values of sunflower were higher than soybean, indicating that sunflower was the dominant species.  Also, the highest density for herbivores was recorded in soybean monoculture and the families of Thripidae (۳۷.۶۰- ۴۳.۸۷%) and Cicadellidae (۳۴.۰۱-۳۷.۷۱%) had the most relative density. Furthermore, intercropping of sunflower with soybean increased pollinators and natural enemies’ abundance compared with monocultures. Overall, based on the ecological, agronomical and economical indices intercropping sunflower with soybean with ratio of ۲۵:۷۵ is a feasible alternative method to achieve similar production with respect to monocropping.

کلیدواژه ها:

Herbivore ، Intercropping ، Land equivalent ratio ، Shannon index ، Total land output