Impact of advanced nitrogen sources on nutrient uptake, yield and economic returns of finger millet

Abstract

A field experiment was conducted during rabi 2022-23 at S.V. Agricultural College, Tirupati, to evaluate the effects of novel nitrogen sources on finger millet (Eleusine coracana) growth, nutrient uptake, yield, and economics. Nine treatments involving combinations of urea and Nano Biochar Nitrogen (NBN) were arranged in a randomized block design with three replications. The results demonstrated that applying 75% Recommended Dose of Nitrogen (RDN) through urea combined with 15 kg ha⁻¹ NBN significantly enhanced grain and straw yields, as well as nitrogen, phosphorus, and potassium uptake, compared to other treatments. This was statistically comparable to 50% RDN with 15 kg ha⁻¹ NBN. The lowest yields and nutrient uptake were observed in the treatment with 50% RDN + 5 kg ha⁻¹ NBN. Economically, treatment 75% Recommended Dose of Nitrogen (RDN) through urea combined with 15 kg ha⁻¹ NBN achieved the highest gross returns and net returns due to increased yield and efficient nutrient use. It also recorded the best benefit-cost ratio, indicating greater profitability and cost-effectiveness for farmers. These findings indicate that integrating nano biochar nitrogen with reduced urea doses improves nutrient efficiency, productivity, and profitability of finger millet cultivation under dryland conditions, presenting a viable strategy for sustainable and cost-effective nutrient management.