Evaluation of qualitative traits of forage turnip in intercropping with basil and influence of biochar and vermicompost application

Document Type : Research Article


1 Department of Agronomy and Plant Breeding, Karaj branch, Islamic Azad University, Karaj, Iran

2 Department of Agronomy, Karaj Branch, Islamic Azad University, Karaj, Iran

3 Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran



Intercropping reduces the use of chemical pesticides to control pests and weeds, which in turn reduces the environmental risks associated with the use of chemical pesticides (Himmelstein et al., 2017). Biochar as a soil amendment and because of its potential to retain water and nutrients, prevent to nitrogen leaching, increased soil fertility and improves plant growth (Fang et al., 2018; Munoz et al., 2016). Other benefits of vermicompost is increased stability of soil resources, maintenance of production, reduction of environmental pollution and increase soil biological activity too (Demir, 2019). Therefore, the purpose of this study was to investigate the quality of forage turnip leaves in different intercropping ratios of forage turnip and basil using biochar as soil amendment and vermicompost.

Materials and Methods

A biennial study was conducted on the quality performance of forage turnip (Brassica rapa var. Rapa) in the form of split plot factorial in a randomized complete block design with three replications in the research farm of Islamic Azad University of Karaj in two years (2018-2019). The treatments of this study include: intercropping in four ratio (100% forage turnip (mono culture), 90% forage turnip + 10% basil, 80% forage turnip + 20% basil, 70% forage turnip + 30% basil), in main plots, and vermicompost in two levels (15, 18.5 ton ha-1) and biochar in two levels (No consumption and 5 ton ha-1) which was placed in subplots. The forage turnip cultivar was PacFB05. In this study, Photosynthetic pigments were measured by (Arnon, 1967) method, membrane permeability (Ferrat and Loval, 1999), relative moisture content (Bertin et al., 1996), soluble leaf sugars (Sheligl, 1986), catalase (Dazy et al., 2008) and soil respiration (Isermeyer, 1952). Using SAS software (Ver.9) for data analysis of two-year experiment and analysis of means was done with the Duncan’s test in significant at 5% probability level. Excel software was used to plot the graphs.

Results and Discussions

The results of this study indicated that with increasing the ratio of basil in intercropping, the quality traits of forage turnip leaves increased too. Consumption of biochar as well as application of vermicompost at the level of 18.5 ton.ha-1 increased the quality of forage turnip leaves. The highest chlorophyll a ((17.52 mg/gFw), chlorophyll b ((8.76 mg/gFw)) total chlorophyll ((26.38 mg/gFw), carotenoids ((6.91 mg/gFw)), relative water content (59.54%), of soluble sugars (69.43%), catalase (0.018 micromole Fresh weight/min) related to Interaction of (70% forage turnip + 30% basil) × vermicompost 18.5 ton ha-1 × application of biochar. The highest value of membrane stability index was related to 100% forage turnip × vermicompost 15 ton ha-1 (4.85 (mol ml-1s-1)). The highest amount of soil respiration is related to the interaction of vermicompost 18.5 ton ha-1 × 70% forage turnip + 30% basil with value of ( 0.28 (micromole gsoil-1hour-1)), interaction of biochar ×70% forage turnip + 30% basil ( 0.32 (micromole gsoil-1hour-1)), and interaction of vermicompost of 18.5 ton ha-1 × biochar ( 0.31 (micromole. g soil-1.hour-1)). Due to potential of biochar (water and food retention and prevent of nitrogen leaching) it can increase the availability of water and nutrients for the plant, which leads to increased photosynthesis of the plant and thus the quality of forage turnip leaves (Akhtar et al., 2015; Hammer et al., 2015). Vermicompost increases soil organic matter and increases the uptake of zinc, copper, iron, phosphorus, potassium and nitrogen of soil. The presence of these elements in the soil and its absorption by the roots increases vegetative growth and leaf production in the plant, which causes the level of light absorption, photosynthetic level, the formation of hydrocarbons in the leaves and the resulting growth also increases Leaf quality (Theunissen et al., 2010).


The results of this study indicated that the application of vermicompost 18.5 ton ha-1 and biochar increased forage turnip quality, which is due to the availability of water and nutrients for forage turnip. The best intercropping ratio was related to 70% forage turnip + 30% basil, which can be said to be due to the increase in the percentage of basil and the competition of plants for better use of intercropping components of growth sources such as light, water and food.


Main Subjects


Articles in Press, Accepted Manuscript
Available Online from 08 June 2022
  • Receive Date: 04 February 2022
  • Revise Date: 06 June 2022
  • Accept Date: 08 June 2022
  • First Publish Date: 08 June 2022