Relation between nitrogen nutrition index and production of spring malting barley

Document Type: Research Paper

Authors

Department of Agro-Environmental Chemistry and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, 165 21 Praha 6 - Suchdol, Czech Republic.

Abstract

Although the nitrogen nutrition index (NNI) is a widely used indicator of plant nitrogen
status, no model of NNI calculation for spring barley (
Hordeum vulgare) reflecting also specific
malting requirements on grain has been published. The aim of this study was to determine
an optimal range of the nitrogen nutrition index (ratio of nitrogen concentration in shoot
biomass to critical nitrogen concentration) with respect to optimal grain protein content
(N × 6.25 = 9.0 – 11.5 %), plump grain (grain > 2.5 mm) yield and lodging of spring malting
barley during 7-year (2007 – 2013) strict field experiments realized under the conditions of three
experimental sites in the Czech Republic. A dose of 80 kg N/ha and 130 kg N/ha, respectively,
was applied in mineral fertilizers. The nitrogen nutrition index was determined at the BBCH 30
(beginning of stem elongation) and BBCH 45 (late boot stage) growth stages. The most suitable
indicators for evaluation of the nitrogen concentration in shoot biomass of the spring malting
barley in our experiments proved to be Justes et al.´s model N
c = 5.35 DM(-0.442) designated for
winter wheat and Zhao´s model N
c = 4.76 DM(-0.39) designated for winter barley, where DM is
shoot dry matter in t/ha. The nitrogen nutrition index for spring malting barley should not
exceed a value of NNI = 0.80 and NNI = 0.90 using the Justes et al.´s model and the Zhao´s one
during the BBCH 30 – 45 growth stages.

Keywords