Impact of nano urea and nitrogen optimization on growth and nutrient uptake in chickpea (Cicer arietinum L.)

This study evaluated the effects of nano-urea on growth, nutrient uptake, and nitrogen use efficiency (NUE) in chickpea (Cicer arietinum L.) under controlled pot culture conditions. The experiment was conducted in a shade net house at the Department of Soil Science, Dr. PDKV, Akola, during the Rabi season of 2022-23, utilizing a Completely Randomized Design (CRD) with seven treatments, each replicated three times. Black Vertisol soil, characterized by low nitrogen, high phosphorus, moderate potassium, near-neutral pH, and medium organic carbon, was used. Application of nano-urea at 4 ml L⁻¹ during flowering and pod development significantly increased plant height, branch number, root length, root dry weight, and total dry matter accumulation. The combination of recommended dose of fertilizer (RDF) and nano-urea maximized nitrogen, phosphorus, and potassium uptake in chickpea, comparable to other RDF-nano-urea treatments. Post-harvest soil analysis revealed that the highest residual levels of nitrogen, phosphorus, and potassium were maintained in the RDF with two nano-urea foliar sprays treatment, indicating effective nutrient retention. Nitrogen use efficiency analysis showed that reducing nitrogen fertilizer by 50% with two nano-urea foliar applications resulted in soil nitrogen mining, whereas treatments with RDF alone or combined with nano-urea demonstrated excess nitrogen supply. A 25% reduction in nitrogen, supplemented with two foliar applications of IFFCO nano-urea, was optimal for balancing chickpea nitrogen demand with efficient nutrient utilization. These findings highlight nano-urea's potential in sustainable chickpea cultivation by reducing chemical fertilizer requirements without compromising plant growth or soil nutrient status.