Effect of nano urea and nano zinc on crop productivity and nutrient dynamics in maize (Zea mays L.) under mid-hills of Himachal Pradesh

Maize (Zea mays L.) is an important cereal crop with high nutrient requirements, particularly nitrogen (N), phosphorus (P) and potassium (K). However, inefficient utilisation of N, can result in substantial nutrient losses and increased production costs. Nano-fertilisers such as nano urea and nano zinc have emerged as promising alternative to conventional fertilisers. The present experiment was laid out at Agricultural Farm of Shoolini University, Solan, Himachal Pradesh in randomised block design (RBD) comprising 9 nutrient management treatments, 3 replications and 1 variety. The experimental results exhibited maximum growth parameters, viz., plant height (228.5 cm) and dry matter accumulation (146.14 g plant-1) in treatment (T7) 100 % PK + 75 % N + 1 foliar spray (FS) (Nano urea + Nano zinc), which was statistically at par with (T3) 100 % recommended dose of fertilisers (RDF) + 1 FS nano zinc 1.5 mL L-1. The highest yield attributing characters viz., no. of cobs plant-1 and no. of grains cob-1 were recorded into treatment T7 which were recorded statistically at par with T3. Conjoint application of nano urea and nano zinc along with 25 % reduced conventional N was recorded highest grain, stover and biological yield which were increased to the tune of 32.8, 26.0 and 28.6 % over to (T2) 100 % RDF (120 : 60 : 40 kg ha-1) for grain, stover and biological yield, respectively. Total N, P and K uptake were also increased to the tune of 36.9, 41.9 and 31.1 % in treatment T7 as compared to T2. Among the treatments, (T8) 100 % PK + 4 FS nano urea + 1 FS nano zinc fetched maximum cost of cultivation (₹42337 ha-1) whereas, highest economic returns in terms of gross returns (₹134767 ha-1), net returns (₹93414 ha-1) and benefit–cost (B : C) ratio (2.26) were fetched in treatment (T7) 100 % PK + 75 % N + 1 FS (Nano urea + nano zinc).