Chlorophyll Meter-Based Dynamic Nitrogen Management in Wheat (Triticum aestivum L.) Under Subtropical Environment

• Published in: Current Agriculture Research Journal Vol. 4; no. 1; pp. 54 - 61
• Main Authors: Hasan, Md, Khaliq, Qazi, Baset Mia, Md, Bari, Md, Islam, Md
• Format: Journal Article
• Language: English
• Published: Bhopal Enviro Research Publishers 28.06.2016
• Subjects: Agricultural production; Agriculture; Agronomy; Chlorophyll; Efficiency; Experiments; Fertilizers; Nitrogen; Physiology; Productivity; Seeds; Soil sciences; Statistical analysis; Wheat
• ISSN: 2347-4688; 2321-9971
• DOI: 10.12944/CARJ.4.1.05

Injudicious use of nitrogen fertilizer is very commonly practice in tropical and subtropical regions. SPAD (Soil-Plant Analysis Development) chlorophyll meter-based nitrogen top-dressing may reduce the risk of under or over application. Considering this, the study was conducted to measure the relative advantage of dynamic methods of nitrogen fertilization over conventional method in wheat field. For this, conventional nitrogen (CN) treatments i.e. CN60, CN90, CN120, CN150 at 60, 90, 120 and 150 kg ha-1 were compared with four chlorophyll meter-based dynamic nitrogen (DN) treatments i.e. DN80, DN90, DN120, DN100 at 80, 90, 120 and 100 kg ha-1 nitrogen. Irrespective of treatments, SPAD meter readings remained above 45 (threshold value) beyond 50 days after seeding, but plant performance varied depending on the methods and doses used in nitrogen top-dressing. Treatment CN150 performed better displaying the highest SPAD values, total dry matter production, leaf area index, crop growth rate and net assimilation rate resulting to the highest grain yield (5.10 t/ha) in wheat. The plant performance in DN120, DN100, DN90 and CN120 treatments were statistically similar to that of CN150 in respect of all most all plant characters studied. Comparing with CN treatments, DN treatments resulted in better plant growth and grain yield at the same level of nitrogen fertilizer. This is because of maintaining need-based fertilizer at early stage of wheat and application of appropriate amount of nitrogen fertilizer in each time in DN treatments compared to CN treatments. The result suggests that chlorophyll meter can be effectively used for real time nitrogen top-dressing to increase productivity of wheat.