Evaluation of Biochar and Vermicompost Application on some Morphophysiological Characteristics of Oenothera biennis under Drought Stress

The aim of this study was to investigate the effect of biochar produced from wastes from pruning of pomegranate trees and compare it with vermicompost Oenothera biennis under drought stress.

Treatments included different levels of organic modifier application (seven levels including no modifier application, application of 10, 20 and 30 ton ha-1 vermicompost and application of 10, 20 and 30 ton ha-1 biochar) and three levels of drought stress (irrigation in 80, 60 and 40% of field capacity (FC)).

The results showed that drought stress significantly decreased leaf length, leaf area, stem diameter, plant height, chlorophyll index and relative water content (RWC) while increased the ratio of root dry weight to shoot and ion leakage. Application of 30 ton ha-1 biochar and all application levels of vermicompost decreased root dry weight to shoot ratio under severe drought stress. All application levels of vermicompost were increased the chlorophyll index under severe stress while different levels of biochar had not significant effect. All amendments significantly increased RWC compared to the control under moderate and severe stress conditions. Application of 30 ton ha-1 biochar and vermicompost decreased ion leakage compared to the control.

It seems that organic amendments can help the plant in stressful conditions by affecting the availability of nutrients and increasing the soil moisture holding capacity. In this study the effectiveness of vermicompost was better compared to biochar, which can be attributed to the higher content of nutrients in vermicompost.