بوم شناسی کشاورزی (Nov 2021)
Evaluation the Yield and Intercropping Indices of Millet (Panicum miliaceaum L.) and Quinoa (Chenopodium quinoa Willd.) under Effect of Plant Density and Cultivation Ratios in Birjand Region
Abstract
Introduction Intercropping is one of the main strategies to obtain more stability in agro-ecosystems. The possibility of yield improvement in intercropping systems depends on various factors such as plant combination, cultivar type, plant density, planting pattern, and contribution of each species. Introducing new crops or forgotten plants to agro-ecosystems are other methods for sustainable crop production. Quinoa as a potential new crop to be introduced to Iran’s farming systems, is well-adapted to different environmental conditions. This plant has high nutritional values and produces acceptable yield to areas affected by environmental stresses like drought and salinity stresses. Millet, as a forgotten crop in Iran’s agro-ecosystems, is a drought-tolerant grain, with appropriate growth and yield in arid and semi-arid regions. This C4 plant has vertical leaf distribution, rapid and short growth period which make it tolerant to adverse environmental conditions compared to other cereals. The aim of this study was to evaluate the possibility of quinoa and millet intercropping under arid and semi-arid climate of Birjand, Iran.Materials and Methods A factorial experiment based on a randomized complete block design (RCBD) with three replications was conducted in research field of University of Birjand, Iran, in 2018. The experimental factors were planting density at three levels (20, 40, and 60 plants m-2 for both quinoa and millet) and planting ratio at five levels (pure stand of millet (100 %), three rows of millet and one row of quinoa (75%-25%), the equal ratio of millet and quinoa (50%-50%), one row of millet and three rows of quinoa (25%-75%) and monoculture of quinoa (100%). Experimental plots area was 24 m2 (6 m×4 m), with eight planting rows per each. The distances between planting rows in all treatments were 50 cm, while the distances along the single rows were 10, 5, and 3.3 cm for 20, 40, and 60 planting densities, respectively. The grain and biological yields of both plants were determined, finally, various indices including land equivalent ratio (LER), relative yield (RY), competitive ratio index and aggressively index were calculated. Data analyses were done using SAS 9.2 and means were compared by FLSD test at 5% probability level.Results and DiscussionThe simple and interaction effects of planting density and ratio had a significant effect on grain and biological yield of quinoa and grain yield of millet (P < 0.01). In addition, planting ratio had a significant effect on the biological yield of millet (P < 0.01). Based on data obtained from monoculture system, the optimum plant density to obtain the highest grain yield of millet (4100 kg.ha-1) and quinoa (2340 kg.ha-1), were 60 and 40 plants per m2, respectively. Considering the different ratios of planting, the participation and positive effect of both millet and quinoa plants in an increasing the land equality ratio has been equal. By increasing the density, the advantage of mixed cultivation has been reduced. The best intercropping systems in terms of LER (1.32) were the density of 40 plants per m2 (for both crops), and planting ratio of 25% millet and 75% quinoa, which had 26.98% actual grain yield incensement. In addition, the results of interaction effect showed that this treatment increased the biological yield of quinoa (6935 kg ha-1) by 9.26%, based on anticipated yield. In this density, it seems that the result of optimal use of existing inputs and reduction of internal and external competition in order to achieve maximum yield has been achieved. The results of the relative yield indicated that the millet is better utilized from environmental resources and conditions due to its predominance and competitiveness. In general, the results of evaluating mixed culture indicators based on the principles of assistance and competition were complementary and confirming each other.ConclusionsThe results showed that millet and quinoa had significant effects on each other when intercropped at different planting densities and ratios due to difference of morphological and physiological characteristics. So according to the goals of intercropping recommended the intercropping systems of millet and quinoa for Birjand region.
Keywords
