Grain yield and nitrogen use efficiency of pearl millet as affected by plant density, nitrogen rate and splitting in sandy soil

Abstract

Field experiments were conducted in Libya, during the 2008 and 2009 summer cropping seasons, to assess the effect of plant density (20×104, 25×104 and 33.3×104 plants/ha), nitrogen fertilizer rates (60, 90, 120 and 150 kg N/ha) and number of N doses (3, 6 and 9 splits) on grain yield and N use efficiency (NUE) of pearl millet in sandy soil. Results showed that plant density had significant effects on plant height, panicle length, 1000-grain weight, grain weight per panicle, number of panicles/m2, grain yield/ha and grain protein content as well as NUE. Sowing pearl millet at 25×104 gave the highest values of the studied traits in both seasons, except 1000-grain weight, grain weight per panicle and grain protein content, which performed well under the lowest plant density (20×104). On the other hand, increasing plant density significantly increased number of panicles/m2. Growth, yield and its components were increased with increasing N rates up to 150 kg/ha, as well as grain protein content. Applying N at 60, 90, 120 and 150 kg/ha resulted in NUE of 23.61, 17.43, 14.01 and 11.99 kg grains/applied N in 2008 and 24.46, 17.72, 14.00 and 11.89 kg grains/applied N in 2009, respectively. Increasing N splitting numbers significantly increased all the studied traits in the 2 cropping seasons. The maximum grain yields (2300.5 and 2450.3 kg/ha in 2008 and 2009 seasons, respectively) were obtained from plants grown at 25×104 and applied with 150 kg N/ha divided into 9 doses, while the highest values of NUE (29.68 and 30.01 kg grains/kg applied N in 2008 and 2009, respectively) were obtained from plants sown at 25×104 and applied with 60 kg N/ha divided into 9 doses