پديد آورندگان :
اسدي، قربانعلي دانشگاه فردوسي مشهد - دانشكده كشاورزي - گروه زراعت , خرم دل، سرور دانشگاه فردوسي مشهد - دانشكده كشاورزي - گروه زراعت , شهرياري، روشنك دانشگاه فردوسي مشهد - دانشكده كشاورزي - گروه زراعت , رنجبر، فاطمه دانشگاه فردوسي مشهد - دانشكده كشاورزي - گروه زراعت , اقحواني شجري، مهسا دانشگاه فردوسي مشهد - دانشكده كشاورزي - گروه زراعت
كليدواژه :
توان رقابتي , شاخص برداشت , كشت مخلوط , نسبت برابري زمين
چكيده فارسي :
به‌منظور ارزيابي عملكرد و اجزاي عملكرد ذرت شيرين تحت تأثير نسبت‌هاي كشت مخلوط رديفي سري جايگزيني با ارقام لوبيا، آزمايشي در قالب طرح بلوك‌هاي كامل تصادفي با سه تكرار در مزرعه تحقيقاتي دانشكده كشاورزي دانشگاه فردوسي مشهد در سال زراعي 93-1392 اجرا شد. تيمارها شامل نسبت‌هاي جايگزيني 75+25، 50+50 و 25+75درصد ذرت شيرين (رقم چيس) با پنج رقم لوبيا (قرمز، چشم‌بلبلي، سفيد، چيتي و توده محلي) و كشت خالص هر دو گياه بود. نتايج نشان داد كه عملكرد دانه ذرت شيرين در كشت خالص بيشتر از كشت مخلوط بود و با افزايش تراكم در نسبت‌هاي مخلوط با ارقام لوبيا به‌طور معني‌داري افزايش يافت. بالاترين و كمترين عملكرد دانه در بين نسبت‌هاي مخلوط به‌ترتيب براي 75درصد ذرت شيرين+25درصد لوبيا با 734/81 گرم بر متر‌مربع و 25درصد ذرت شيرين+75درصد لوبيا با 346/6 گرم بر متر‌مربع به‌دست آمد. بالاترين ميانگين عملكرد دانه ارقام لوبيا در نسبت كاشت 75درصد لوبيا+ 25درصد ذرت شيرين با 7/165گرم بر متر‌مربع و پايين‌ترين ميزان براي 25درصد لوبيا+ 75درصد ذرت شيرين با 77/8گرم بر متر‌مربع حاصل شد. بالاترين عملكرد دانه در لوبيا چشم‌بلبلي (234/23گرم بر متر‌مربع) و كمترين ميزان در توده محلي (84/8گرم بر متر‌مربع) مشاهده شد. بالاترين نسبت برابري زمين براي نسبت 25درصد لوبيا توده محلي+75درصد ذرت شيرين (1/47) به‌دست آمد. نتايج تيمارها نشان داد كه توده محلي نسبت به ساير ارقام لوبيا توان رقابتي بيشتري نسبت به ذرت شيرين داشت
چكيده لاتين :
Introduction
Conservation agriculture (CA) has been proposed as a set of principles that could help reverse widespread soil degradation in the region and help farmers stabilize yields by mitigating the effects climate variability. Though numerous questions remain on how CA practices might fit in a complex mix grain- grazing farming systems, where limited land, cash and labor impose severe constraints on farmers’ options. Intercropping is a CA approach that has been traditionally practiced in many parts of world and has some advantages over monocultures. One of its obvious advantages may be to increase forage protein, the principle being improvement of forage quality through the complementary effects of two or more crops grown simultaneously on the same area of land. Intercropping supplies efficient resource utilization, reduces risk to the environment and production costs, and provides greater financial stability, making the system more suitable particularly for labor-intensive, small farmers. Morpho-physiological differences and agronomic factors such as the proportion of crops in the mixture and fertilizer application regulate competition between component crops for growth-limiting factors. Greater total uptake of nutrients and other growth factors by the component crops in the intercropping is the primary cause of obtaining intercropping advantage. Intercropping research studies involving a cereal and a legume have not considered the combined effect of fertilizer application and plant population variation. Maize and beans are important food crops, mostly grown by resource- poor farmers in complex and risky farming systems. Morgado & Willey (2003) showed that competitive effect of intercrop beans on maize yields was high at higher plant populations.
Materials & Methods
In order to study the production potential and competitiveness of sweet corn and bean varieties, an experiment was carried out based on a randomized complete block design with three replications in the Agricultural Research Station, Ferdowsi University of Mashhad, during growing season of 2014-2015. Treatments included different combinations of bean (B) and sweet corn (C): 25%B+75%C, 50%B+50%C, 75%B+25%C and bean varieties and their monoculture. Bean varieties consisted cowpea, white, red, pinto and landrace and chase sweet corn. Studied criteria were yield components (pod number per plant, seed number per pod and 100-seed weight), biological yield, seed yield and harvest index (HI) of bean and biological yield, seed yield and HI of sweet corn and land equivalent ratio (LER).
Results & Discussion
The results indicated that effect of intercropping ratios were significant (p≤0.05) on seed yield, biological yield, HI, pod number per plant and seed number per pod and biological yield and seed yield of bean. The highest seed yield of bean was observed in 75%B + 25%C with 1675 g.m-2 and the lowest was related to 25%B + 75%C with 778 g.m-2. The maximum seed yield was obtained in pinto (2342.33 g.m-2) and the minimum was achieved in landrace (847.75 g.m-2). Seed yield of sweet corn in monoculture was higher than intercropping ratios, but by increasing density in intercropping ratios with bean varieties it significantly enhanced. The highest and the lowest seed yield in intercropping ratios were observed in 75%C + 25%B with 7348.1 g.m-2 and 25%C + 75%B with 3466 g.m-2, respectively. In all combinations of intercropping ratios LER was higher than 1, that it represents intercropping is better than monoculture. The maximum land equivalent ratio was calculated with 1.47 for 25%B (landrace) + 75%C. The results showed that landrace was competitive than other varieties.
Conclusion
The effect of intercropping ratios of sweet corn with bean landraces were significant (p≤0.05) on seed yield, biological yield, HI and yield components of the crops. The maximum seed yield was obtained in pinto and the minimum was achieved in landrace. Seed yield of sweet corn in monoculture was higher than intercropping ratios, but by increasing density in intercropping ratios with bean varieties it significantly enhanced. According to the results, intercropping of plants of 25%B (landrace) + 75%C can be beneficial in term of ecological management.
