Identification of characteristics affecting nitrogen utilization efficiencies in wheat cultivars

Abstract

The present study elucidates variations in biomass nitrogen utilization efficiency (NutE₁) and yield nitrogen utilization efficiency (NutE₂) among 21 wheat cultivars and determines their relationships with carbon/nitrogen (C/N) ratio, harvest index at the final harvest, and percent nitrogen (N) losses. The data obtained from the cultivars evaluated in a field trial at uniform N level on a loamy sand soil have shown NutE₁ and NutE₂ values ranging from 38.31 – 53.08 and 18.20 – 30.97, respectively. The C/N ratio, harvest index, and % N losses from anthesis to maturity varied from 16.49 – 22.47, 0.42 – 0.64 and 27.38 to −33.61, respectively. C/N ratio correlated positively with both NutE₁ and NutE₂; whereas harvest index showed a positive correlation with NutE₂ only. N losses were negatively correlated with NutE₁ and NutE₂ as well as with C/N ratio and harvest index. The cultivars with higher NutEs also exhibited higher C/N ratio and harvest index and lower N losses. Therefore, it comes out that C/N ratio, harvest index and N losses from anthesis to plant maturity significantly contribute to NutEs of wheat cultivars.

Keywords:

• Biomass
• nitrogen utilization efficiency
• C/N ratio
• harvest index
• nitrogen losses
• wheat
• yield

Acknowledgements

The financial support of Council of Scientific and Industrial Research, Government of India, is gratefully acknowledged. The authors also thank Prof. Y. P. Abrol for his keen interest in this study.