بررسی شاخص‌های سودمندی کشت مخلوط گلرنگ (carthamus tinctorius l.) با نخود (cicer arietinum l.)، عدس (lens culinaris medik.) و خلر (lathyrus sativus l.)

به‌منظور ارزیابی شاخص‌های سودمندی کشت مخلوط گلرنگ (carthamus tinctorius l.) با نخود (cicer arietinum l.)، عدس (lens culinaris medik.) و خلر (lathyrus sativus l.) در شرایط دیم، آزمایشی به‌صورت کرت‌های خرد شده بر پایه طرح بلوک‌های کامل تصادفی در سه تکرار در سال زراعی 1398- 1397 در مزرعه تحقیقاتی پردیس کشاورزی و منابع طبیعی دانشگاه رازی اجرا شد. تیمارهای آزمایش شامل سه گونه لگوم نخود، عدس و خلر به‌عنوان عامل اصلی و آرایش‌های کشت مخلوط شامل کشت خالص گلرنگ، کشت با نسبت 25:75 گلرنگ و لگوم، کشت با نسبت 50:50 گلرنگ و لگوم، کشت با نسبت 75:25 گلرنگ و لگوم و کشت خالص لگوم به‌عنوان عامل فرعی در نظر گرفته شد. گلرنگ گیاه اصلی و نخود، عدس و خلر به‌عنوان گیاه جایگزین بودند. در بین گونه‌های مورد بررسی، بیشترین نسبت برابری زمین (1.14) متعلق به گیاه همراه نخود بود. صرف نظر از نوع گونه لگوم در بین الگوهای کشت مخلوط، نسبت 50:50 گلرنگ و لگوم از نظر نسبت برابری زمین (1.26) و ضریب ازدحام نسبی (4.6) نسبت به دیگر الگوها برتری داشت. میزان کاهش عملکرد واقعی برای همه الگوهای مخلوط مثبت بود، امّا در شرایطی که گیاه نخود (0.62) به‌عنوان گیاه همراه کشت شد، این کاهش به‌طور معنی‌داری بیشتر از سایر گیاهان بود. بیشترین شاخص بهره‌وری در الگوهای مختلف کشت در تیمار 25:75 گلرنگ و عدس و به‌میزان 7722 کیلوگرم در هکتار مشاهده شد. به‌طور کلی، نتایج نشان داد که در بین گونه‌های لگوم همراه با گیاه گلرنگ، بیشترین سودمندی هنگامی که نخود به‌عنوان گیاه همراه انتخاب شد، به‌دست آمد و الگوی کشت مخلوط 50:50 نیز از برتری بالاتری نسبت به سایر تیمارها برخودار بود.

studying the beneficial indicators of intercropping of safflower (carthamus tinctorius l.) with chickpea (cicer arietinum l.), lentil (lens culinaris medik), and bitter vetch (lathyrus sativus l.)

introduction intercropping is an agroecological technique in which two or more species are grown in the same area for a certain period of time. these species should be complementary to each other regarding the use of productive resources. by selecting crop species with different growth habits and minimal competition, intercropping optimizes resource absorption, resulting in improved yields compared to monoculture. many studies have shown that intercropping systems improve the resources used, stability of production, and increased profitability per area. the aim of this study was to evaluate the beneficial indicators of intercropping of safflower, an important oil plant, with three legume species, including chickpea, lentil, and bitter vetch, under kermanshah climatic conditions. materials and methods a split plots experiment was done based on a completely randomized block design in three replications in dryland conditions at the research farm of the campus of agriculture and natural resources, razi university, during 2018-2019. in this study, chickpea, lentil, and bitter vetch were assigned to the main plots, and five intercropping arrangements included legume monoculture, 75:25 ratio of safflower and legume, 50:50 ratio of safflower and legume, 25:75 ratio of safflower and legume, and safflower monoculture were assigned to the subplots. in this research, safflower was the main crop, and chickpeas, lentils, and bitter vetch were considered as alternative crops. the beneficial indicators of intercropping, including land equivalent ratio (ler), relative crowding coefficient (rcc), system productivity index (spi), and actual yield loss (ayl) were calculated. the ler indicates the amount of land required for the crop in monoculture in order to achieve a similar yield as intercropping. the rcc indicates the competitive ability of crops grown in intercropping. in other words, it expresses the relative dominance of one species over others in intercropping. the spi data are calculated by standardizing the alternative crop based on the main crop, whose higher values indicate the enhanced efficiency of the intercropping system. the ayl indicates the decrease or increase in the yield of intercropping compared to monoculture. the data were analyzed using anova, and the means were compared with the lsd test. results and discussion the results showed that the ler in intercropping with chickpeas and lentils was higher than that in other treatments. regardless of legume species, among the cultivation patterns, the 50:50 ratio of safflower and legume was superior in terms of ler (1.26) and competition index (rcc=4.6) compared to other intercropping patterns. the amount of actual yield reduction was positive for all intercropping patterns, but in the conditions where the chickpeas were cultivated as a companion crop in the intercropping, it was significantly more than the condition where the bitter vetch was cultivated as a companion crop (ayl=0.62). the highest productivity index in intercropping patterns was obtained when lentils were cultivated together with safflower (6089). the advantage of intercropping has been reported in many studies, especially those in which one of the components of intercropping is legume species, and the results of the current research are consistent with them. intercropping provided better growth conditions for safflower compared to its monoculture. the different morphology of safflower compared to chickpea, lentil, and bitter vetch allows for minimal competition for resource uptake. the nitrogen fixation ability and facilitative effects of these legume species improved the indicators of intercropping profitability and ultimately increased safflower yield compared to its monoculture.