اثر كشت مخلوط افزايشي لوبيا سبز (Phaseolus vulgaris L) بر رشد، عملكرد معادل و كارايي استفاده از زمين سيب‌زميني (Solanum tuberosum L) تحت سطوح مختلف كود نيتروژنه

Effect of Green Bean (Phaseolus vulgaris L.) Additive iIntercropping on Growth, Potato (Solanum tuberosum L.) Equivalent Yield and Land Use Efficiency under Different Levels of N Fertilizer

يكي از راهكارهاي حركت به‌سمت كشاورزي پايدار، ايجاد تنوع و به‌كارگيري كشت مخلوطي از گياهان، ارقام و يا ايزولاين­ هاي مختلف در زراعت است. هم‌چنين جهت افزايش بهره­ وري در نظام كشاورزي، مديريت منابع و نهاده ­ها نيز نقش اساسي دارند. به همين دليل در اين آزمايش واكنش سيب‌زميني (.Solanum tuberosum L) به الگوهاي مختلف كشت (كشت خالص سيب­ زميني و كشت­هاي مخلوط افزايشي لوبيا سبز (.Phaseolus vulgaris L) در بين رديف­ هاي سيب‌زميني، روي رديف­ هاي سيب‌زميني و بين و روي رديف­ هاي سيب‌زميني) و سطوح نيتروژن (صفر، 80 و 160 كيلوگرم نيتروژن در هكتار) بررسي شد. آزمايش به­ صورت فاكتوريل بر پايه بلوك­هاي كامل تصادفي در سه تكرار در مزرعه تحقيقاتي دانشكده كشاورزي دانشگاه بوعلي سينا و در سال زراعي 1395 اجرا شد. ويژگي­هاي زراعي، اجزاي عملكرد و عملكرد سيب ­زميني، عملكرد معادل سيب ­زميني، عملكرد غلاف لوبيا سبز، نسبت برابري زمين و مجموع ارزش نسبي اندازه‌گيري و مورد تجزيه و تحليل قرار گرفت. بيش‌ترين عملكرد غده سيب­ زميني (42/50 تن در هكتار) از تيمار كشت مخلوط بين‌رديفي­ لوبيا سبز با دريافت 160 كيلوگرم نيتروژن به­ دست آمد كه با تيمار كشت مخلوط بين‌رديفي­ لوبيا سبز با دريافت 80 كيلوگرم نيتروژن (با عملكرد معادل 41/51 تن در هكتار)، اختلاف معني ­داري نداشت. هم‌چنين، بالاترين عملكرد غلاف لوبيا سبز (515 گرم در مترمربع)، نسبت برابري زمين (1/53)، مجموع ارزش نسبي (1/45) و بالاترين عملكرد معادل سيب ­زميني (54/38 تن در هكتار) از تيمار كشت مخلوط بين‌رديفي­ لوبيا سبز با دريافت 80 كيلوگرم نيتروژن به ­دست آمد. بنابراين، تيمار كشت مخلوط بين‌رديفي­ لوبيا سبز با دريافت 80 كيلوگرم نيتروژن از نظر رشد، عملكرد غده، بهبود كارايي استفاده از زمين و كارايي مصرف نيتروژن مناسب­ترين تيمار بود. در كل، كشت لوبيا سبز در بين رديف­ هاي سيب­ زميني به‌دليل تعلق آن­ها به دو تيره مختلف و تفاوت ­هاي اكولوژيكي، مورفولوژيكي و تغذيه ­اي، جنبه هاي هم­ياري و مكملي مناسبي در كشت مخلوط دارند. اين امر موجب افزايش بهره ­وري بهتر از زمين، نور و مواد غذايي موجود در واحد سطح و نيز افزايش تنوع در اكوسيستم­ هاي كشاورزي مي­ گردد.

Introduction One of the ways to move towards sustainable agriculture is to create diversity and using intercropping of crops, cultivars and / or different isolines in agriculture. In order to increase productivity in the agricultural system, resource management and inputs also play a key role. In addition, to preserve ecological balance and stability of the system, the main goals in the intercropping systems are maximum exploitation of environmental resources such as water, soil, food, the quantitative as well as qualitative increase of yield, and reduction of damage from pests, diseases, and weeds. In addition, improvement social conditions, such as greater economic stability and adequate nutrition for humans are pursued. Therefore, the present study aimed to exploit the agro-ecological benefits of additive intercropping of green bean in reduction of nitrogen consumption in potato cultivation and improving the land use efficiency and potato equivalent yield. Materials and Methods In order to evaluate the effects of additive intercropping of green bean on potato growth, tuber yield, nitrogen use efficiency, land use efficiency, and potato equivalent yield as well as green bean yield, an experiment was conducted at the Farm Research of Faculty Agriculture (latitude 35◦1'N, longitude 48◦31'E and 1690 m altitude), Bu-Ali Sina University, Hamedan, Iran, in the growing season of 2016. Experiment was laid out as a factorial based on randomized complete block design with three replications. Four planting patterns including sole cropping of potato (M1), green bean intercrops between potato rows (M2), green bean intercrops within potato rows (M3) and green bean intercrops between and within potato rows (M4) were applied in combination with three levels of nitrogen fertilizer (N0, N80 and N160: 0, 80 and 160 kg N ha-1, respectively). Intercropping system was done using additive design. So that, the potato density was kept constant and in all cropping patterns, 50% sole green bean planting density was added to potato plots. Traits of plant height (PH), tuber yield (TY), number of tuber per plant (NTP), tuber dry matter (TDW), harvest index (HI), and potato equivalent yield (PEY) for potato, and green bean pod yield (GPY), number of pods per plant (NPP), and biological yield (BY) for green bean were evaluated. Land equivalent ratio (LER), relative value total (RVT) indices were also studied. Results and Discussion Results demonstrate that planting pattern and N had the strongest influence on tuber equivalent yield as well as tuber yield of winter wheat followed by interactions between these treatment factors. Accordingly, when normal and high N levels were applied, potato equivalent yield values were comparable to, or higher than, those obtained without consumption of N. The highest potato tuber yield (42.50 t.ha-1) was revealed at the treatment of green bean intercrops between potato rows with consumption of 160 kg N ha-1. This treatment did not show significant difference with the treatment of green bean intercrops between potato rows with consumption of 80 kg N ha-1, which had a yield of 41.51 t.ha-1. Also, the highest values for yield of green beans (515 g.m-2), the land equivalent ratio (1.50), total relative value (1.45) and the highest potato equivalent yield (54.38 t.ha-1) were obtained at M2 × N80 (green bean cultivation between potato rows with consumption of 80 kg N ha-1) treatment. Legumes have the ability to nitrogen fixation and using of them in intercropped systems can be suitable for reduce nitrogen use as well as environmental problems. Therefore, in terms of growth, tuber yield, land use efficiency and nitrogen utilization efficiency, treatment of green bean intercrops between potato rows with consumption of 80 kg N ha-1 was the best treatment for potato production. Conclusion In general, the cultivation of green beans between potato rows due to ecological, morphological and nutritional differences has cooperation aspects in intercropping. This will increase the productivity of the land, the light and food in the unit area and the diversity in agricultural ecosystems.