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 obtained in case of treatment T12 even less than control (3.26). Higher relative growth rate was observed in the treatments which comprised of application of RDF along with micronutrients as compared to RDF alone and control treatment. The highest RCGR was recorded in the treatment RDF + application of Mo and the lowest in case of control. RDF accumulated lesser dry matter than the treatments which comprised of micronutrient application through soil application. Almost similar trend was observed in case of absolute growth rate. The highest dry matter accumulation was observed in case of RDF + Mo (soil application) and lowest in case of control. RDF accumulated lesser dry matter than the treatments which comprised of micronutrient application through soil application. Almost similar trend was observed in case of dry matter production. The highest no. of nodules per plant (39.6) was recorded in the treatment T3: RDF + Mo (Soil application). This treatment was found significantly superior to rest of the treatments. Lowest numbers of nodules per plant were recorded in control treatment which was found statistically inferior to all the treatment except T12. Agronomic efficiency is enhanced due to application of micronutrients when applied with RDF. Application of FYM alone also gave higher AE than RDF. Lowest AE was recorded in case of farmer’s practice where 50 kg DAP was applied per ha. The highest applied recovery efficiency for all the nutrients was recorded in the treatment T3, and lowest in case of Farmer’s practice. This emphasized the importance of balance fertilization in enhancing nutrient use efficiency. The highest photosynthesis rate (6.11, µmol CO2m-2s-1) was recorded in the treatment T3- RDF+ Mo soil application, this treatment was found at par with the treatments T4 T5, T6, T7, T8, T9, and T11. Rests of the treatments were significantly inferior to T3 treatment. Application of micronutrients along with RDF enhances photosynthesis rate in soybean crop as compared to RDF alone, farmer’s practice, absolute control and FYH alone. The highest transpiration rate was recorded in T3- RDF+ Mo (2.11 µmol H2O m-2s-1), which was found statistically at par with all the treatments except T1, T2, T11 and T12. The transpiration rate recorded in control treatment was found statistically inferior to the rest of the treatments. The stomata conductance commensurate the trends of photosynthesis rate being highest in T3 and lowest in control. This parameter was also affected significantly by different treatments. The water use efficiency has been enhanced due to application of Micronutrients along with RDF as compared to RDF alone, farmer’s practice, application of FYM alone @ 10tha-1 and control. Over all conclusion drawn from the study that the application of Mo and Zn may be commended along with RDF to achieve higher crop productivity and crop quality of soybean when grown in Vertisols.

Download this article as