Nitrogen Fertilizer Complements Breeding in Improving Yield and Quality of Milling Oat

Abstract

A four‐level nitrogen (N) fertilizer study was conducted for nine diverse oat (Avena sativa L.) cultivars at three geographically diverse locations in Canada in 2013 and 2014 to study the effects of N fertilizer on grain yield and important quality parameters of milling oat. Analysis of variance and biplot analysis were used to interpret the multifactor, multitrait data. The findings are: (i) N fertilizer up to 150 kg ha−1 led to simultaneous and statistically significant improvement of grain yield, milling quality (groat content and proportion of undehulled kernels), and compositional quality (β‐glucan, protein, and oil concentrations), despite some N × genotype and N × environment interactions. (ii) β‐Glucan and oil concentrations were much more strongly determined by genotype than by N fertilizer; groat content and proportion of undehulled kernels were slightly more strongly determined by genotype than by N fertilizer; protein was similarly determined by genotype and N fertilizer; and grain yield was much more determined by N fertilizer than by genotype. (iii) Nitrogen fertilizer effectively increased the yield of high‐β‐glucan, low‐yielding cultivars but had a limited (though statistically significant) effect in improving the β‐glucan levels of cultivars that are low in β‐glucan. (iv) Cultivars differed in the extent of response to N fertilizer, so it is necessary to develop cultivar‐specific N management plans for different cultivars. It is proposed to use N fertilizer to improve yield (and, to a lesser extent, quality parameters) to complement breeding prioritizing superior quality (high β‐glucan in particular) and lodging resistance.

Rapid UHPLC-MS metabolite profiling and phenotypic assays reveal genotypic impacts of nitrogen supplementation in oats

“…The difference between varieties was greater than the difference between nitrogen treatments. A similar result was found by Yan et al ( 2017 ). Plant height also increased with nitrogen application (Table 1 ) as found in other studies (May et al 2004 ; Ma et al 2017 ) indicating that the increased yield and grain quality at higher N levels could come with an associated higher risk of lodging (Tumino et al 2017 ).…”

“…Total protein content as measured by NIR significantly increased with nitrogen application but there was no significant difference between the four varieties (Table 1 ). Total oil content however was significantly different between varieties and decreased significantly in response to nitrogen as also found by Yan et al ( 2017 ). Mascani had the lowest total oil content.…”

“…The effects of nitrogen application during oat yield development on grain quality parameters are however poorly understood compared with wheat and barley. Provision of a sufficient amount of nitrogen, usually in the form of urea or anhydrous ammonia, has great bearing on the plant height, quality and oat yield (Chalmers et al 1998 ; Givens et al 2004 ; Yan et al 2017 ). Oat quality and yield in turn impact upon the processing quality of oats, with respect to dehulling, as well as the later processing steps of flaking and milling (Browne et al 2003 ).…”

Genotype and Management Evaluation Based on Genotype by Yield*Trait (GYT) Analysis

“…In contrast, N applications had positive effects including increased yield, groat, β-glucan, and protein and reduced oil, but adverse effects including reduced test weight and increased lodging. These results are consistent with earlier N-fertilizer studies on oat [5,9,10]. So, it is important to find a N treatment or management package so as to maximize the positive effects and minimize the negative effects of nitrogen fertilizer.…”

“…The purpose of the study was to identify superior oat cultivars, agronomic managements, and their combinations, for use in milling oat production in northern Ontario. In addition to yield, good lodging resistance, high levels of test weight, groat content, β-glucan content, and protein content and low levels of oil are considered desirable for milling oat [3][4][5].…”