Opportunities for Increased Nitrogen Use Efficiency in Wheat for Forage Use.

Nirmal Sharma,Malay C Saha,Soonil Kwon,Raquel Schneider-Canny,Konstantin Chekhovskiy

doi:10.3390/plants9121738

Nirmal Sharma, Malay C Saha + Show 3 more

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https://doi.org/10.3390/plants9121738

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Abstract

Wheat is a major cool-season forage crop in the southern United States. The objective of this study is to understand the effect of nitrogen (N) fertilization on wheat biomass yield, quality, nitrogen use efficiency (NUE), and nitrogen nutrition index (NNI). The experiments were conducted in a greenhouse and a hoop house in a split-plot design, with three replications. Twenty wheat cultivars/lines were evaluated at four N rates (0, 75, 150, and 300 mg N.kg−1 soil) in the greenhouse and (0, 50, 100, and 200 mg N.kg−1 soil) in the hoop house. In general, high-NUE lines had lower crude protein content than the low-NUE lines. None of the cultivars/lines reached a plateau for biomass production or crude protein at the highest N rate. The line × N rate interaction for NUE was not significant in the greenhouse (p = 0.854) but was highly significant in the hoop house (p < 0.001). NNI had a negative correlation with NUE and biomass. NUE had strong positive correlations with shoot biomass and total biomass but low to moderate correlations with root biomass. NUE also had a strong positive correlation with N uptake efficiency. Lines with high NUE can be used in breeding programs to enhance NUE in wheat for forage use.

Highlights

Wheat is a unique and versatile dual-purpose crop in the southern GreatPlains of the United States [1]
Interactions were significant for biomass, NUpE, and nitrogen use efficiency (NUE) (Table 1)
Except for NUpE, the rest of the variables (biomass, crude protein (CP), N utilization efficiency (NUtE), and NUE) showed high R2 values (>80%), which indicate that most of the variation can be explained by the statistical model used

Summary

Introduction

Plains of the United States [1] It is a good choice for winter pasture production in the region due to its high nutritive value and biomass potential [2]. Wheat supplies high-quality forage during late fall, winter, and early spring when other common forage species are not productive [4,5]. Farmers usually apply 18% more nitrogen (N) in wheat fields utilized for forage and grain than for grain only [3]. The recommended N fertilizer rate in wheat pastures in Oklahoma is 33 kg.ha−1 of N for every 1.1 Mg.ha−1 of forage yield. N is usually the most limiting nutrient associated with wheat forage production [7]

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