Balance sheet method assessment for nitrogen fertilization in bread wheat: I. yield and quality

Abstract

In the European Union the production of high quality wheat is mainly located in the Mediterranean regions where the climatic conditions positively affect protein concentration in the grain. High quality wheat calls for proper management of nitrogen fertilization, thus there is a need to verify whether the limitations imposed by local governments on maximum rate of nitrogen fertilization admitted may affect bread making quality. Trials were conducted in fourteen environments (E) to study the effects of different nitrogen fertilizations on eight cultivars (C), belonging to four quality grades (Q). Nitrogen (N) was applied to crops according to three rates/modalities: N1 corresponding to the maximum rate admitted calculated according to a balance sheet method and distributed at the stage of spike initiation; N2 with 50 kg ha-1 of nitrogen more than N1, also distributed at the stage of spike initiation; N3 with 50 kg ha-1 of nitrogen more than N1 but distributed at the stage of flag leaf appearance. The effects of environment, nitrogen and cultivar were significant for grain yield, test weight, 1000 kernel weight, heading time, plant height and for quality traits (protein content and alveograph indices). The existence of variability among cultivars and quality grades in the response to rate and timing of nitrogen fertilization was demonstrated by the significance of NxC and NxQ interactions. Dry matter and nitrogen contents of plant at anthesis and at harvest were significantly affected by the main sources of variation. High quality cultivars yielded more grain of better quality with higher N rates (N2 and N3) as compared to the maximum rate of nitrogen admitted by the local government (N1). These results demonstrated that the adopted balance sheet method for the calculation of N requirements of wheat crop adversely affects the full potential expression of the cultivars belonging to superior bread making quality grades

Effect of late-season nitrogen fertilization on grain yield and on flour rheological quality and stability in common wheat, under different production situations

“…The rate and timing of N applications are crucial factors, not only to obtain high yields, but also to increase GPC, gluten and the rheological parameters (Borghi et al, 1997;Garrido-Lestache et al, 2005;Corbellini et al, 2006). Generally, in Southern European climatic conditions, the application of N fertilizer is split into two distributions: a first granular N fertilization is applied at tillering [growing stage (GS) 20] (Zadoks et al, 1974) and a second one at the beginning of stem elongation (GS 31)].…”

Decision rules for managing N fertilization based on model simulations and viability assessment

“…Until now, the total rate of N fertilizer to be applied on a crop was managed based on average response curves to N fertilization (Meynard et al, 1981;Berti et al, 2016), or with a nondynamic balance-sheet method (Meynard et al, 1997;Alvarez et al, 2004;Corbellini et al, 2006). Improvements have been proposed with decision-support tools based on the measurement of an indicator (nitrate concentration of stem base sap; indirect measurement of chlorophyll concentration in the leaves through reflectance or transmittance) and the corresponding recommended rate (Justes et al 1997;Olfs et al, 2005;Samborski et al, 2009).…”

Biofortification of Common Wheat Grains with Combined Ca, Mg, and K through Foliar Fertilisation

“…Among the most interesting strategies to enhance wheat quality, late-season (between earing and flowering) foliar nitrogen spraying has shown promising results in terms of increased grain protein content [35]. The rate and timing of N application are crucial factors to achieve yield improvements, as well as enhance protein content, gluten quality, and rheological parameters [36][37][38]. There is currently attention on biofortification practices targeting nutrients malnutrition, i.e., by enriching plants with desirable elements against the so-called hidden hunger [39][40][41].…”