Effects of mycorrhizae as a substitute for inorganic fertilizer on growth and yield of tomato (lycopersicon esculentum l.) and soy bean (glycine max l.),

Abstract

A greenhouse experiment was conducted to determine the influence of mycorrhizae as a substitute for inorganic fertilizer on growth and yield of Tomato (Lycopersicon esculentum) and Soybean (Glycine max) and soil microbial activity. Four doses of inorganic fertilizers viz recommended dose [Tomato- Urea:TSP:MOP=65:325:65 kg/ha and Soybean Urea:TSP:MOP=35:130:35 kg/ha), 1/2 and 1/4 of recommended dose and 0 dose] were applied to soil with standard dose of mycorrhizae (2 g/5L water). The above four treatments were tested in a Completely Randomized Design (CRD) with five replicates. Results indicated that there was no significant difference in all parameters tested on plants treated with recommended dose and 1/2 of recommended dose of inorganic fertilizer with standard dose of mycorrhizae. The highest fruit wet weight (556 g/plant - 69% higher than the lowest) in tomato plants and the highest pod wet weight (18 g/ plant) in soybean was observed with ½ of the recommended dose of inorganic fertilizer and lowest was observed in plants treated with standard dose of mycorrhizae without inorganic fertilizer (tomato -329 g/plant and soybean 4 g/plant). However the highest pod dry weight (8 g/plant) and seed dry weight (7 g/plant) were observed in 1/2 of recommended dose of inorganic fertilizer with standard dose of mycorrhizae in Soybean. The highest soil microbial activity was recorded in soil treated with standard dose of mycorrhizae without inorganic fertilizer (464 CO2 mg/kg of soil - 61% higher than the recommended dose of inorganic fertilizer) and the lowest was observed in soil treated with recommended dose of inorganic fertilizer (287 CO2 mg/kg of soil). The activities of soil microorganisms were lower in soils treated with inorganic fertilizers considering the growth parameters and soil microbial activity it can be concluded that 1/2 of the recommended dose of inorganic fertilizer with standard dose of mycorrhizae is the best fertilizer mixture for crops, tomato and soybean. Addition of mycorrhizae to the field soil increases the soil microbial activity significantly.