DYNAMICS OF YIELD, NITROGEN UPTAKE AND NITROGEN USE EFFICIENCY IN WHEAT (Triticum aestivum L.) CROP AS INFLUENCED BY LEAF COLOUR CHART AND CHLOROPHYLL METER BASED REAL TIME NITROGEN MANAGEMENT

REENA¹*, V.C. DHYANI², SUMIT CHATURVEDI³, SHIKHA^4
1Department of Agronomy, G.B. Pant University of Agriculture & Technology, Pantnagar, 263145, Uttarakhand, India
²Department of Agronomy, G.B. Pant University of Agriculture & Technology, Pantnagar, 263145, Uttarakhand, India
³Department of Agronomy, G.B. Pant University of Agriculture & Technology, Pantnagar, 263145, Uttarakhand, India
⁴Subject Matter Specialist (Soil Science), Krishi Vigyan Kendra, Ranichauri, 249199, Uttarakhand, India
* Corresponding Author : agronomistreena@yahoo.com

Received : 15-12-2017     Accepted : 21-12-2017     Published : 24-12-2017
Volume : 9     Issue : 54       Pages : 4930 - 4933
Int J Agr Sci 9.54 (2017):4930-4933

Keywords : Agronomic efficiency, Chlorophyll meter (SPAD meter), Leaf-colour chart (LCC), Recovery efficiency, Total nitrogen uptake, Wheat, Yield
Academic Editor : Arun K Zingare, Uadal Singh, Ashok Yadav
Conflict of Interest : None declared
Acknowledgements/Funding : The Authors would like to acknowledge the Director, Experiment Station, G.B. Pant University of Agriculture & Technology, Pantnagar-263145, Uttarakhand, India, for providing the necessary facilities to conduct the present M. Sc. research.
Author Contribution : The present study was conducted by authoress in partial fulfillment for post graduate degree programme, under the guidance of second and third author in the Department of Agronomy, College of Agriculture, G. B. Pant University of agriculture and Technolog

The present study was carried out at G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarkahand, during the rabi season of 2014–15 to assess the dynamics of yield, nitrogen uptake and nitrogen use efficiency in wheat crop as influenced by leaf colour chart and chlorophyll meter based real time nitrogen management. Real time nitrogen management including two split top dressing of 40 kg N/ha (40 kg/splits) at LCC (4 and 5) and SPAD (35 and 40) along with 25 kg as basal (total 105 kg/ha) and one split top dressing of 40 kg N/ha at SPAD 40 along with 40 kg at crown-root initiation and 25 kg as basal (total 105 kg/ha) reported numerically 15 to 24 per cent and 15 to 22 per cent higher values of agronomic and recovery efficiency respectively when compared with recommended 150 kg N/ha without any significant decrement in yield attributes, biological yield, grain yield and total N uptake. Thus LCC and SPAD based management of 105 kg N/ha make more effective use of absorbed nitrogen with the saving of 30 per cent or 45 kg N/ha. Although higher net returns and B:C ratio obtained in the recommended practice compared to next best treatment, i.e. application of 25 kg N as basal + two splits top dressing of 40 kg at SPAD 40,there could be substantial fertilizer saving with the SPAD based real time N management. Study revealed that among given threshold values LCC 5 and SPAD 40 was better than LCC 4 and SPAD 35 for best management of nitrogen in wheat crop.

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