Improving Nitrogen Use Efficiency in Dual-Purpose Maize Production through Optimized Nutrient Scheduling

Timely and effective rate of nitrogen (N) and application is essential in enhancing the maize productivity and nitrogen use efficiency (NUE) in semi-arid areas of Pakistan. To determine the impacts of five N-rates, N0-N4 (0, 80, 120, 160, and 200 kg N ha-1) and three split applications S1 (whole sowing), S2 (two splits - 1/2 at sowing + 1/2 at tasseling) and S3 (three splits - 1/3 at sowing + 1/3 knee height, and 1/3 at tasseling) on maize were applied. The findings indicated that there was a significant increase in growth and yield characteristics with increasing N rate and in split application. The highest performance shown in N4 and S3 as, plant height (232.60 and 210.80 cm), cob length (23.27 and 21.8 cm), cob diameter (6.63 and 5.97 cm), grain rows per cob (15.78 and 14.93 cm), grains per cob (574 and 502), and hundred grain weight (32.96 and 29.25 g) was measured. Similarly, the highest grain yield (8.14 and 7.69 t ha-1), and biological yield (27.75 and 25.72 t ha-1) was observed under N4 and S3 which was (32.3 and 13.1 %), and (60.6 and 23.0%) higher than the lowest control treatments as N0 and S1. The forage performance also increased as the green fodder yield was improved to 43.56 t ha-1 (42.5%), dry matter yield 18.39 t ha-1, crude protein content was raised to 10.26% and crude protein yield (202.03 kg ha-1 in S1 and N0) was upgraded 194%. As NUE was highest at the moderate rates of N, whereas the largest Partial Factor Productivity (PFP) (74.71 kg kg-1), Agronomic Efficiency (AE) (48.59 kg kg-1), Recovery Efficiency (RE) (61.68%), and Physiological Efficiency (PE) (84.09 kg kg-1) were obtained at S3 and 80 kg N ha-1. In general, three-split N application at a moderate and higher N rate maximized the productivity of maize and the efficiency of nitrogen utilization.