title: Nitrogen Source and Rate Management Improve Maize Productivity of Smallholders under Semiarid Climates.
abstract: Nitrogen is one of the most important factor affecting maize (Zea maysL.) yield and income of smallholders under semiarid climates. Field experiments were conducted to investigate the impact of different N-fertilizer sources [urea, calcium ammonium nitrate (CAN), and ammonium sulfate (AS)] and rates (50, 100, 150, and 200 kg ha-1) on umber of rows ear-1(NOR ear-1), number of seeds row-1(NOS row-1), number of seeds ear-1(NOS ear-1), number of ears per 100 plants (NOEP 100 plants-1), grain yield plant-1, stover yield (kg ha-1), and shelling percentage (%) of maize genotypes "Local cultivars (Azam and Jalal) vs. hybrid (Pioneer-3025)." The experiment was conducted at the Agronomy Research Farm of the University of Agriculture Peshawar during summers of 2008 (year one) and 2010 (year two). The results revealed that the N treated (rest) plots (the average of all the experimental plots treated with N) had produced higher yield and yield components, and shelling percentage over N-control plots (plots where N was not applied). Application of nitrogen at the higher rate increased yield and yield components in maize (200 > 150 > 100 > 50 kg N ha-1). Application of AS and CAN had more beneficial impact on yield and yield components of maize as compared to urea (AS > CAN > urea). Hybrid maize (P-3025) produced significantly higher yield and yield components as well as higher shelling percentage than the two local cultivars (P-3025 > Jalal = Azam). Application of ammonium sulfate at the rate of 200 kg N ha-1to hybrid maize was found most beneficial in terms of higher productivity and grower's income in the study area. For the two local cultivars, application of 150 kg N ha-1was found more beneficial over 120 kg N ha-1(recommended N rate) in terms of greater productivity and growers income.
authors.affiliation: Department of Agronomy, Faculty of Crop Production Sciences, The University of Agriculture Peshawar, Pakistan.
authors.lastname: Amanullah
authors.affiliation: Department of Agronomy, Faculty of Crop Production Sciences, The University of Agriculture Peshawar, Pakistan.
authors.forename: Asif
authors.initials: A
authors.lastname: Iqbal
authors.affiliation: Department of Agronomy, Faculty of Crop Production Sciences, The University of Agriculture Peshawar, Pakistan.
authors.forename: Ashraf
authors.initials: A
authors.lastname: Ali
authors.affiliation: Crop Physiology and Production Center, College of Plant Science and Technology, Huazhong Agricultural University Wuhan, China.
authors.forename: Shah
authors.initials: S
authors.lastname: Fahad
authors.affiliation: ICAR- Indian Institute of Rice Research, Soil Science Hyderabad, India.
authors.forename: Brajendra
authors.initials: B
authors.lastname: Parmar
keywords: N levels; N source; Zea mays L.; genotypes; grain yield; shelling percentage; yield components