Opportunities for Increased Nitrogen Use Efficiency in Wheat for Forage Use

Area of Science:

• Agronomy
• Plant Science
• Forage Production

Background:

• Wheat is a key cool-season forage crop in the southern US.
• Optimizing nitrogen fertilization is crucial for maximizing yield and quality.
• Understanding nitrogen use efficiency (NUE) and nitrogen nutrition index (NNI) is vital for sustainable agriculture.

Purpose of the Study:

• To investigate the impact of nitrogen (N) fertilization on wheat biomass yield, quality, NUE, and NNI.
• To identify wheat cultivars with superior NUE for forage applications.
• To explore the relationship between NUE, biomass, and nutritional content.

Main Methods:

• Greenhouse and hoop house experiments were conducted using a split-plot design with three replications.
• Twenty wheat cultivars/lines were subjected to four different nitrogen rates.
• Biomass yield, crude protein content, NUE, and NNI were measured and analyzed.

Main Results:

• High-NUE wheat lines generally exhibited lower crude protein content compared to low-NUE lines.
• No cultivars reached a biomass or crude protein plateau even at the highest N rates.
• The interaction between wheat line and N rate significantly affected NUE in the hoop house but not in the greenhouse.
• NNI showed a negative correlation with NUE and biomass.
• NUE strongly correlated with shoot and total biomass, and N uptake efficiency, but less so with root biomass.

Conclusions:

• Wheat lines with high NUE can be valuable resources for breeding programs aiming to enhance forage production.
• Further research is needed to optimize N management strategies for different wheat cultivars.
• The findings provide insights into the genetic potential for improving NUE in wheat for forage.