Yield, nutrient uptake, nutrient use efficiency of wheat as affected by different sources of nutrients and levels of nutrients in vertisols

Modern crop production technologies require balanced fertilizer use. An experiment was conducted at JNKVV, Jabalpur during the Rabi season of 2019-20 to evaluate the yield, nutrient uptake, and nutrient use efficiency of wheat as affected by different nutrient sources and levels in Vertisols. The main challenges of the study included the non-uniform nutrient release from organic sources, the differing nutrient availability among inorganic, organic and integrated sources which made equal comparison difficult, and the potential risk of nutrient losses or uneven uptake at higher NPK levels. The treatments included three nutrient sources as main plots: inorganic, organic (FYM, vermicompost, and biofertilizers), and integrated sources (50% inorganic + 50% organic). Five NPK levels were tested as sub-plots: control (0-0-0 kg NPK ha⁻¹), 100% NPK (120-60-40 kg ha⁻¹), 150% NPK (180-90-60 kg ha⁻¹), 200% NPK (240-120-80 kg ha⁻¹), and soil test value (STV) NPK (149-176-33 kg ha⁻¹), in a split-plot design with three replications. Results revealed that inorganic nutrient sources produced significantly higher grain yield, NPK uptake (grain and straw), and nutrient use efficiencies- agronomic efficiency, recovery efficiency, physiological efficiency, and factor productivity- compared to organic and integrated sources. Among NPK levels, 150% NPK gave significantly higher yield and nutrient uptake than lower levels and was at par with 200% NPK. Moreover, across all interactions and treatment combinations, the inorganic nutrient source combined with 150% NPK consistently resulted in the highest yield and nutrient use efficiency. The study identifies the most efficient nutrient source and NPK level for Vertisols, providing a practical recommendation that enhances wheat yield and nutrient use efficiency in central India.