Evaluation of quantitative, qualitative, and economic aspects of garlic (Allium sativum L.) and fenugreek (Trigonella foenum-graceum L.) intercropping under organic and chemical nutrition systems

This experiment was conducted as split-plot in a randomized complete block design with three replications at the research farm of University of Gonabad in the 2017-18 crop year. The main plot included control, chemical fertilizer (100, 120, and 150 kg.ha-1 urea, triple superphosphate, and potassium sulphate, respectively), and vermicompost (10 t.ha-1) and sub-plot consisted of garlic (Allium sativum L.) and fenugreek (Trigonella foenum-graceum L.) intercropping in 25:75, 50:50, 75:25, and 100:100 proportions and sole cropping of two crops. The results showed that the highest number and bulblet length was obtained in the chemical fertilizer treatment, however there was no significant difference between this treatment and vermicompost. While, the vermicompost treatment resulted in the highest bulblet diameter. The highest bulblet number was obtained in the 50:50 intercropping treatment and the highest length and bulblet diameter was obtained in the 25:75 one. The highest biological yield and bulb yield (3867 and 2293 kg.ha-1) was obtained in the sole cropping of garlic and chemical fertilizer treatment. The highest garlic essential oil was obtained in the vermicompost (2.33%) and 50:50 intercropping (2.36%) treatments. The plant height and number of pods per plant in fenugreek had the highest increase (30 and 21%, respectively) in the chemical nutrition treatment. Also, the highest number of pods per plant was obtained in the 25:75 intercropping treatment. The highest forage and seed yield of fenugreek (2057 and 682 kg.ha-1, respectively) was observed in the sole cropping and chemical fertilizer treatment. The biological yield was higher in the chemical (2800 kg.ha-1) and organic (2733 kg.ha-1) fertilizer treatments under sole cropping. The highest essential oil of fenugreek seeds was observed in the chemical fertilizer (1.16%) and 75:25 intercropping (1.12%) treatments. The intercropping patterns recorded the land equivalent ratios above 1 and the best situation was obtained from 100:100 intercropping. Garlic was superior to fenugreek in the intercropping treatments except for 100:100 pattern. The intercropping advantage was greater than 1 except for the 100:100 treatment and the highest economic advantage was obtained in the 25:75 pattern and organic fertilizer treatment.