The present investigation was carried out in Kharif season during the year 2009 under All India Coordinated Research Project for Dryland Agriculture, College of Agriculture, Indore. A field experiment under rainfed conditions was laid out in randomized block design with twelve treatments at the College of Agriculture Farm, Indore in field No.19 during the Kharif season of 2009. The objectives of the study were: -To evaluate the response of application of micronutrient viz. Zn, Mo, B and Fe to soybean grown in Vertisols under rainfed condition; To evaluate comparative performance of soil and foliar application methods used for micronutrient application; To evaluate the effect of Micronutrient application on physiological processes of soybean such as photosynthesis, respiration, stomatal conductance, leaf temperature, and chlorophyll content. There were twelve treatments and each of them was randomized and replicated three times. The design used in the experiment was randomized block design. The gross plot size was 5.0 m X 4.0 m and after leaving non-experimental margin on both sides, the net experimental plot size was 4.00 m X 3.20 m. Soybean [Glycine max (L.) Merrill] crop (cv. JS-9305) was sown on July 1, 2009. The highest seed yield was recorded in the treatment T5-RDF+ Zn (Soil application) 25 Kg ZnSO4 (2471 kgha -1 ) followed by T3: RDF + Mo (Soil Application) 0.5 kg/ha (2450 kgha -1 ), T4: RDF + Mo (Foliar Application) 0.1% Amm. Molybdate (2376 kgha -1 ), T9-RDF + Fe (Soil Application)(2353 kgha -1 ), T10-RDF + Fe (Foliar Application) (2325, kgha -1 ), T7-RDF+ B (Soil Application) (2166kgha -1 ), T8-RDF + B (Foliar Application) (2128 kgha -1 ), T6-RDF + Zn (Foliar Application) (2209, kgha -1 ), T2-Recommended dose of NPKS (2034 kgha -1 ), T11-Organic manure @ 10 tha -1 (1831 kgha -1 ), and lowest in control (1731, kgha -1 ). All the treatments are statistically at par except the treatment T1 and T12 i.e. control and addition of organics alone. Seed yield data revealed that treatments comprising of soil application of micro nutrient gave higher seed yield when applied with RDF than foliar application of micronutrient. This statement is true for all the micro nutrients applied In case of straw yield also. Test weight and chlorophyll content in leaves were also affected significantly by different Treatments. In case of test weight treatments T2 (14.8g) gave the highest test weight. Lowest test weight was recorded in the treatment T1 control. The highest chlorophyl content was recorded in the treatment T3-RDF + Mo (Soil Application) (40.8 SPAD) which was closely followed by the treatment T4-RDF + Mo (Foliar Application) 0.1% Amm. Molybdate, T5-RDF+ Zn (Soil application), T7-RDF+ B (Soil Application). All these treatments were statistically at par with the treatment T3-T2 + Mo (Soil Application). While the treatment T3 was found statisticaly superior to the rest of the treatments. Soil application of micronutrient was found more economical than foliar application of micro nutrient. The lowest B: C ratio was obtai...