عنوان مقاله [English]
Cultivation of medicinal plants in agricultural ecosystems plays an important role in the diversification and sustainability of these systems (Rezaei-Chiyaneh & Dabbagh Mohammadi Nassab, 2014). Therefore, the application of ecological principles such as multi-ship system seems essential in the production of these plants. Zarifpour et al. (2014) in intercropping arrangements of cumin and chickpea showed that different cropping patterns had a significant effect on chickpea and cumin yield and the highest essential oil and land equivalent ratio achieved by planting ratio 50% cumin + 50% chickpea. Therefore, the objectives of the present study were to examine the effect of different intercropping patterns of black cumin and basil with bean on their yield and qualitative traits.
Materials and methods
In order to evaluate some quantitative and qualitative traits of black cumin (Nigella sativa L.) and basil (Ocimum basilicum L.) in different intercropping patterns with bean (Phaseolus vulgaris L.) and land use efficiency, a field experiment was conductedbased on a randomized complete block design with eight treatments and three replications at the farm located in West Azerbaijan province in Nagadeh, Iran during growing reason about 2013-2014. Cropping patterns included row intercropping (one row of black cumin+ one row of bean+ one row of basil) and strip intercropping (one row of black cumin+ two rows of bean+ one row of basil, two rows of black cumin+ four rows of bean+ two rows of basil, three rows of black cumin+ six rows of bean+ three rows of basil, four rows of black cumin+ eight rows of bean+ four rows of basil) and their solecropping.
Black cumin was harvested when they turned brown, dried and shelled, and bean was harvested when the first pod of the plants fully matured and dried. Basil was harvested in the first and the second harvest at 50% of flowering.
Land Equivalent Ratio (LER)
Land equivalent ratio of basil, black cumin and bean was calculated using equation 1 (Koocheki et al., 2014):
Where, Y1, Y2 and Y3 represent basil, black cumin and bean yield in intercropping, respectively and B1, B2 and B3 represent basil, black cumin and bean yield in solecropping, respectively.
Results and discussion
Results revealedthat the economic yield of three plants was significantly affected by treatments and theaverage yield was higher in solecropping than intercropping. By increasing in strip width seed yield of black cumin, dry matter yield in the first,and the second harvest of basil were decreased 30, 29, and 24 percent, respectivelycompared to monoculture. However, seed yield and biological yield of bean did not indicate any significant differences at solecropping with four rows of black cumin+ eight rows of bean+ four rows of basil. Higher seed yield and biological yield of sole cropped may be due to the fewer disturbances in the habitat in homogeneous environment of monocropping systems. Moreover, no significant difference between sole cropping of bean with combinations of 4 rows black cumin+ 8 rows bean+ 4 rows basil may be due to facilitative interaction in this combination. The percentage of essential oil in black cumin and basil of all treatments was higher than solecropping. Higher essential oil yield in intercropped could be due to the positive effect of bean such as nitrogen fixation for black cumin and basil. The essential oil content of black cumin and basil are, furthermore, positively affected by intercropping with bean.The maximum land equivalent ratio (1.93) was obtained in two rows of black cumin+ four rows of bean+ two rows of basil that represents an increase advantages in intercropping than solecropping.
The results showed that quantitative and qualitative yield of three species was affected by planting ratio. The maximum seed and biological yield of three species were obtained at solecropping. The percentage of essential oil in black cumin and basil of all treatments were higher than solecropping. The LER index was higher than one in all intercropping treatments compared to solecropping systems. Generally,it seems that the cropping pattern “two rows of black cumin+ four rows of bean+ two rows of basil“ is remarkably effective to increase the economic income and land use efficiency.