Improving Maize Yield and Nitrogen Use Efficiency Using Spectral Properties of Leaves for Need-based Nitrogen Management

Abstract

There is a spiral increase in maize consumption in Ghana due to high population growth and changing consumer preferences. However, maize yield in the country is declining partly due to poor soil fertility and fertilizer management, resulting in low nitrogen use efficiency. A field experiment was therefore conducted at the Soil and Irrigation Research Centre, University of Ghana, Kpong during the 2016 cropping season to evaluate the effect of nitrogen management options on growth, yield and nitrogen use efficiency of maize. The experiment was laid out in a split plot design with three replicates. Variety and nitrogen (N) management were the main and sub plot factors, respectively. The varieties were; 1. Aburohemaa (V1) 2. Abontem (V2) 3. Obaatanpa (V3). 4. Omankwa (V4), while the nitrogen management levels included; 1. no N application (control, N0), 2. Conventional practice, Conv (150 kg N ha-1) 3. Leaf Colour Chart, LCC (75 kg N ha-1) and 4. Soil Plant Analysis Development meter, SPAD (75 kg N ha-1). The results revealed that LCC and SPAD meter in maize nitrogen-based management reduced nitrogen fertilizer input by 50% without significantly affecting the growth, grain yield and nitrogen use efficiency of maize. Maize varieties significantly differed in terms of growth rate, yielding potential, N uptake and N use efficiency. The study recommended LCC to maize farmers since it is relatively cheap, easy to use and saved 50% N fertilizer input.