Preprint
Article

Impact of Nitrogen Addition on Spring Wheat Physiological and Agronomic Traits Under Contrasting Environmental Conditions

Altmetrics

Downloads

336

Views

452

Comments

0

Submitted:

09 October 2019

Posted:

11 October 2019

You are already at the latest version

Alerts
Abstract
Optimizing the nitrogen (N) timings and rate can improve nutrient uptake, and nutrient-efficiencies, especially of N in wheat under the changing climate scenario. Climatic stress in the form of high temperature and drought resulted in the decreased crop physiology and, ultimately, grain yield. Taking the example of rainfed wheat, we quantified the impact of N application rates as full and split-dose at three variable sites of rainfed Pothwar, Pakistan by conducting field experiments for two years (2013-14 and 201-15). Treatments include, T1 = Control (No fertilizer applied), full dose of N applied at the time of crop sowing, i.e. T2 = 50 kg N ha-1, T3 = 100 kg N ha-1 and T4 = 150 kg N ha-1 and split application of N at different timings during different stages of the crop called as split application of N, i.e. T5: Application of 50 kg N ha-1 (15 kg N ha-1 (Sowing) : 20 kg N ha-1 (Tillering) :15 kg N ha-1 (Anthesis), T6: Application of 100 kg N ha-1 (30 kg N ha-1 (Sowing): 40 kg N ha-1 (Tillering) : 30 kg N ha-1 (Anthesis) and T7: Application of 150 kg N ha-1(45 kg N ha-1 (Sowing) : 60 kg N ha-1 (Tillering) : 45 kg N ha-1 (Anthesis). Three study sites include viz. Islamabad (High rainfall with optimum temperature), University Research Farm (URF)-Koont (Medium rainfall with moderate temperature), and Talagang (low rainfall with high temperature). Results showed that the highest stomatal conductance (0.80 mole m-2 sec-1), net photosynthetic rate (20.07 μmole m-2s-1), transpiration rate (9.58 mmole m-2s-1), intercellular CO2 concentration (329.25 μmole CO2 mol-1 air), SPAD values (58.86 %) and proline contents (35.42 μg g-1) were obtained for split application of N (T6 = Split N100) compared to control and full dose of N treatments. Among sites, these physiological traits remained highest at Islamabad and lowest at Talagang, while among years, maximum values of the measured parameters were obtained in 2013-14. A similar trend was observed for crop total N, N efficiencies, and agronomic traits of the crop. Our results suggest that optimum N application rate and its suitable timings can help to harvest real benefits of N as in our findings, split dose resulted in the maximum performance of the crop from physiological parameters to the agronomic traits of the rainfed wheat crop.
Keywords: 
Subject: Biology and Life Sciences  -   Agricultural Science and Agronomy
Copyright: This open access article is published under a Creative Commons CC BY 4.0 license, which permit the free download, distribution, and reuse, provided that the author and preprint are cited in any reuse.
Prerpints.org logo

Preprints.org is a free preprint server supported by MDPI in Basel, Switzerland.

Subscribe

© 2024 MDPI (Basel, Switzerland) unless otherwise stated