Conjoint Application of Different Nutrient Sources and Biofertilizers for Micronutrient Enrichment and Energy Budgeting in Maize Under Rainfed Conditions

Abstract

Exclusive focus on primary nutrients has reduced the availability of micronutrients to plants, posing a serious threat to nutritional security. Integrated nutrient management (INM) represents a sustainable strategy to improve soil micronutrient availability and crop yield. A study was carried out during kharif (summer) 2022 at the research farm of the Department of Soil Science, Chaudhary Sarwan Kumar Himachal Pradesh Krishi Vishwavidyalaya (CSKHPKV), Palampur to evaluate the influence of INM on maize productivity along with micronutrient concentration in the soil. The experiment comprised of nine treatments with NPK at graded doses (100, 75, and 50%), FYM (7, 10 t ha-1), vermicompost (3.5, 5 t ha-1), and biofertilizers (Azotobacter + Bacillus), replicated thrice under a randomised block design. Maize variety Kanchan (K-25) was opted as the test crop. The experimental soil was acidic (pH 5.63) with silty clay loam soil texture and adequate available micronutrients (Fe, Mn, Zn and Cu). Soil samples were analysed for DTPA-extractable micronutrients and energy indices, while grain and stover samples were analysed for micronutrient concentration and total uptake. The synergistic application of 75% NPK along with 5 t vermicompost ha-1 (T7) and biofertilizers recorded the highest grain and stover yields, improved soil micronutrient availability, and enhanced micronutrient concentration and uptake in maize. Considering the energy indices, energy use efficiency was highest under treatment T9 (50% NPK + 5 t VC t ha-1 + biofertilizers) while other indices were highest under treatment T7. Overall, INM proved effective in improving maize productivity, soil micronutrient status and energy efficiency, highlighting its potential for sustainable crop production.