Evaluation the Appropriate Levels of Vermicompost and Municipal Solid Waste Compost on Nutrient Uptake and Yield of Canola under Drought Stress Conditions

In order to determine the efficiency and appropriate levels of two biofertilizers including municipal solid waste compost and vermicompost on improving nutrient availability, growth and yield of canola under drought stress conditions, an experiment was conducted as factorial arrangement based on randomized complete block design with four replications. Treatments consisted of three levels of drought stress, including no stress, mild stress and severe stress conditions, and biofertilizer combination in five levels including control, application of municipal solid waste compost at two and four percent levels and application of vermicompost at two and four percent. Results showed that the effect of stress and biofertilizer levels on nutrient uptake, growth, and yield was significant. The interaction of drought stress and biofertilizer had significantly affected all traits except nitrogen and zinc percent. The results of mean comparison indicated that the mild and severe stress significantly reduced nitrogen, phosphorous, iron percentage and grain yield of canola and increased potassium and sodium percentage in shoot in comparison with the control group. Application of four percent vermicompost resulted in an increase in biomass, yield and nutrient uptake except zinc, under no stress, mild and severe drought stress compared to other biofertilizer treatments. Overall, it could be concluded that biofertilizers, especially vermicompost, positively affected plant growth under drought stress conditions.