Comparison of some biofertilizers on morphological characteristics and macronutrient content of peppermint (Mentha piperita L.)

Environmental implications of cotinious application of chemical fertilizers, while ongoing demands for healthy products has made the attentions to the sustainable agriculture. Integrated soil nutrient management inclouding part replacement of chemical fertilizers by biofertilizers is among the sustainable agriculture nesseserities in recent years. Varius biofertilizers aleady are producing or importing into Iran's market. This study was conducted to evaluate the efficiency of some biofertilizers with brand names Multifunctional, Bioumik, Fulzyme plus, Nitrokara, Golden Nitrokara and Inoculum on morphological characteristics and concentration of nitrogen (N), phosphorous (P) and potassium (K) of peppermint plant. A greenhouse experiment was conducted with five replications. Four plants was grown in pots containing 5 kg soil treated with 2% w/w solution of biofertilizers, two times during growing period. Results showed that biofertilizers had significant effect on the number of leaves and stems, root fresh weight, as well as shoot P and root and shoot N. The highest effect on root and shoot N (1.49 and 2.26%) and shoot P (1.18%) were related to Bioumik and Nitrokara, respectively. Nitrokara efficiently resulted in increased shoot P, which was significantly higher than the other treatments. According to the results among biofertilizers best N nutrition and number of leaves was with Bioumik while lowest shoot P was observed in this treatment.