Nitrogen Fertilization Strategies for Forage Maize Genotypes: Agronomic Performance, Nitrogen use Efficiency and Economic Assessment and Deter- mination of Economical N Fertilizer Rate

Abstract

A field investigation was conducted using factorial experiment in randomized block design with seven genotypes and three nitrogen (N) levels (80, 120 and 160 kg N/ha) with three replications at Dr Rajendra Prasad Central Agricultural University, Pusa, Bihar, India during kharif season, 2022. The objective of the study was to assess the nitrogen use efficiency, productivity and profitability of forage maize genotypes under different N levels. Among, the genotypes, J-1006 and among N levels, application of 120 kg ha-1 registered the maximum green and dry fodder yield and crude protein yield (CPY). The highest partial factor productivity of N fertilizer (PFPN) was recorded with J-1006 (103.3 kg DM/kg N applied) and application of lowest dose i.e. 80 kg/ha (99.1 kg DM/kg N applied) among genotypes and N levels, respectively. J-1006 (Rs 78109 ha-1 and 3.62) and application of 120 kg N ha-1 (Rs 65716 ha-1 and 3.21) was profitable in terms of net returns and B:C ratio among genotypes and N levels, respectively. The economic optimum dose of N for tested fodder maize genotypes was found to be 139 kg/ha.