Impact of conventional and nano fertilizers on rainfed maize yield, profitability and soil nitrogen

Nitrogen (N) is a vital macronutrient for maize productivity, but significant losses under rainfed conditions limit its availability and yield potential. There is a need for energy-efficient and eco-friendly fertilizers along with improved agronomic practices to enhance nutrient use efficiency, crop productivity, and profitability. An experiment was conducted under semi-arid conditions in India in a single location to evaluate the economic and environmental performance of conventional fertilizers at varying nitrogen levels [0, 50, 75, and 100% recommended rate of nitrogen (RDN)] with and without nano-urea in rainfed maize. Application of 100% recommended NPK through conventional fertilizers along with nano-urea spray (N100PK + nano-urea) recorded significantly higher yield (3,026 kg ha-1) and economic returns (US $ 477 ha-1). Notably, the N75PK + nano-urea registered comparable yield over N100PK + nano-urea and N100PK, demonstrating that two foliar sprays of nano-urea could reduce nitrogen input by 25% without yield loss. Additionally, this approach reduced greenhouse gas (GHG) emissions by 25% and energy consumption by 14.9%, highlighting its potential for sustainable maize production. Though the results are encouraging it should be tested across crops and regions.