The Effect of Nitrogen Fertilizer Application and Planting Pattern on Yield and Competition Indices of Chickpea (Cicer arietinum L.) and Quinoa (Chenopodium quinoa Willd)

IntroductionIntercropping, the agricultural practice of cultivating two or more crops in the same space at the same time, is an old and commonly used cropping practice which aims to match efficiently crop demands to the available growth resources. The practice of growing two or more crops simultaneously in the same field is called intercropping and it is a common feature in traditional farming of small landholders. It provides farmers with a variety of returns from land and labour, often increases the efficiency with which scarce resources are used and reduces the failure risk of a single crop that is susceptible to environmental and economic fluctuation. Intercropping of chickpea with linseed reduced the chickpea yield by 60.3%, although linseed occupied only 33% of the total area. The loss of chickpea yield was compensated by the additional yield of linseed, and thus the system productivity of chickpea + linseed intercropping was increased by 43.4% compared with sole chickpea. Of this increase in system productivity, 65.3 and 34.7% were contributed by higher seed yield and higher minimum prices of linseed, respectively as compared to chickpea. The objectives of the present study were to study the competition indices of chickpea and quinoa intercropping such as land equivalent ratio, relative crowding coefficient, aggressivity, chickpea equivalent yield and effects of nitrogen and different intercropping arrangements on yield of sole chickpea, sole quinoa and intercropping yield of two plants. The objectives of the present study was to determine the best appropriate treatment of sole cropped, replacement and additive series of chickpea and quinoa in terms of yield and investigation of competition indices in intercropping replacement and additive chickpea and quinoa. Materials and MethodsIn order to study the effect of planting pattern and nitrogen application on yield and competitive indicators of chickpea and quinoa, a factorial experiment based on randomized complete block design (RCBD) was conducted with three replications at Gonbad Kavous University farm during the 2020-2021 growing season. Nitrogen factor was included three levels of non-application and application of 25 and 50 kg N.ha-1 and the treatments of intercropping were included 9 levels of sole cropped of chickpea and quinoa, 67% chickpea + 33% quinoa, 50% chickpea + 50% quinoa, 33% chickpea + 67% quinoa, 100% chickpea + 33% quinoa, 100% chickpea + 50% quinoa, 100% chickpea + 67% quinoa and 100% chickpea + 100% quinoa. For analysis variance of data software of SAS Ver. 9.4 was used and treatment mean differences were separated by the least significant difference (LSD) test at the 0.05 probability level. Results and DiscussionResults showed that the effects of planting pattern and nitrogen consumption on yield were significant at confidence level of 1%. The maximum total yield belonged to the treatment sole cropped of chickpea with 3529 kg.ha-1, which was not significantly different from the 67% chickpea + 33% quinoa treatment. With increase of nitrogen fertilizer consumption, total yield was increased. The lowest chickpea crop equivalent yield related to the treatment sole cropped of chickpea and mixed crop was 33% increase of quinoa to chickpea crop with 3529 and 3551 kg.ha-1, respectively, and the highest was related to sole cropped of quinoa with 8876 kg.ha-1. Land equivalent ratio was higher than one in all the additive mixed cropping treatments and alternative mixed cropping treatments. The maximum proportion of land belonging to the treatment of 100% chickpeas + 67% quinoa was 1.10. The relative coefficient of total density in all treatments was more than one, which indicates the desirability of mixed cultivation of chickpea and quinoa. The examination of the aggressivity index showed that quinoa was dominant in the mixed cropping treatments, increasing and replacing the plant. As a result, the dominance index of quinoa was positive despite the favorable yield of both plants. ConclusionsOf the two plants of chickpea and quinoa, quinoa plant produced more yield than chickpea plant. The maximum total yield belonged to the treatment sole cropped of chickpea with 3529 kg.ha-1, which was not significantly different from the 67% chickpea + 33% quinoa treatment. With increasing of nitrogen fertilizer consumption, yield was increased. According to the results, it seems that it is not possible to increase the density of two plants in mixed cultivation to obtain the maximum yield.