THE EFFECTS OF BIOLOGICAL AND CHEMICAL FERTILIZER SOURCES ON THE PRODUCTION AND QUALITY OF SUNFLOWER

Abstract

Bio-fertilizers improve nutrient availability and reduce the need to use chemical fertilizers and hold a great promise to increase crop yields. To study the effects of different nutrition systems, this research evaluated the individual and combined effects of bio-fertilizers and compared their efficiency with nitrogen (N) and phosphorus (P) chemical fertilizers on the yield of sunflower (Helianthus annuus L.) in the 2017–2018 crop year in Hamedan, Iran. The field experiment included a combination of two factorial experiments, consisting of (a) the application of chemical nitrogen (N₀=0, N₁=45, N₂=90 kg ha^-1) and phosphorus (P₀=0, P₁=40, P₂=80 kg ha^-1) fertilizers, and (b) the application of N-fixing bacteria Azospirillum and Azotobacter (BN₀=0, BN₁=0.5, BN₂=1 L ha^-1), and P-solubilizing bacteria Pseudomonas and Bacillus (BP₀=0, BP₁=0.5, BP₂=1 L ha^-1) bio-fertilizers. Each experiment used a 3×3 design with nine treatments and arranged in a randomized complete block design with three replicates. Results indicated that the chemical N and P fertilizers significantly increased the grain yield, thousand-grain weight, plant dry weight, protein percentage, and harvest index. Furthermore, bio-fertilizers significantly increased the grain yield and harvest index. The application of bio-fertilizers with N-fixing bacteria and P-solubilizing bacteria improved the growth and yield characteristics of sunflower. Sunflower oil yield was similar among all treatments, ranged from 2.22 to 5.7 t ha^-1. Grain yield ranged from 5.12 to 5.88 t ha^-1. A similar result between treatments with the chemical and bio-fertilizers suggests that bio-fertilizers are potential alternatives to chemical fertilizers.