Compost and Nitrogen Management Influence Productivity of Spring Maize (Zea maysL.) under Deep and Conventional Tillage Systems in Semi-arid Regions

On-farm research was conducted to investigate the effects of nitrogen (N) and compost (C) on yield and yield components of spring maize (Zea mays L.) under conventional and deep tillage system (T) at the research farm of the University of Agriculture, Peshawar, Pakistan, during spring 2013. The experiment was laid out in a randomized complete block design with split-plot arrangement, using three replications. Three compost levels (0, 1, and 2 t ha−1) and two tillage systems (conventional and deep tillage) were allotted to the main plot, whereas N levels (60, 90, 120, and 150 kg N ha−1) were allotted to subplots in the form of urea. Nitrogen and compost levels had significantly affected all the parameters. Plots treated with 150 kg N ha−1 increased ear length (31 cm), grains ear−1 (413), thousand-grain weight (240.2 g), grain yield (3097 kg ha−1), straw yield (9294 kg ha−1), harvest index (24.7 percent), and shelling percentage (81.7 percent). Compost applied at 2 t ha−1 increased ear length (32 cm), grains ear−1 (430), thousand-grain weight (242.3 g), grain yield (2974 kg ha−1), straw yield (8984 kg ha−1), harvest index (24.6 percent), and shelling percentage (83.2 percent). Tillage system had significant effect on all parameters except ear length and harvest index. Deep tillage system produced more grains ear−1 (365), thousand-grain weight (233.3 g), grain yield (2630 kg ha−1), straw yield (8549 kg ha−1), and shelling percentage (79.6 percent). It was concluded from the results that application of 120 kg N ha−1 + 2 C t ha−1 under a deep tillage system could improve spring maize yield and yield-contributing traits under semi-arid conditions.