Development of intensive nitrogen management strategies for winter barley (Hordeum vulgare L) in the mid-Atlantic region

Winter barley (Hordeum vulgare L.) production in the mid-Atlantic region occupies a substantial amount of arable land. Variable levels of winter and spring precipitation can result in N loss. The objectives of this study were to determine the optimum rate and timing of N fertilization and develop predictors of optimum N rates. An uptake study was conducted to determine N uptake of winter barley with respect to growth stage. Various N rate combinations at growth stages (GS) 25 and GS 30 were evaluated over twenty locations and three cropping seasons, to determine the application regime required to optimize grain yields at each site. Predictor variables at GS 25 and GS 30 were evaluated to predict optimum N rates. The N uptake study indicated an increased N uptake at GS 25 and GS 30. Yields from plots receiving no spring N varied from 1400 to 7530 kg ha⁻¹, at various sites, indicating a yield response of barley to residual N. Optimum N rates over locations varied from 0 to 136 kg N ha⁻¹, suggesting a need to diagnose site-specific N requirements. Plant tissue tests at GS 30 were the best predictor of GS 30 optimum N rates with a critical level of 3.5% N in plant tissue above which no economic response to applied N would be expected. GS 25 tiller density was the best predictor of optimum GS 25 N rates in 1994-1995. This season was climatically atypical thus this method must be evaluated further.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Crop and Soil Environmental Sciences

Department dc:contributor.department

Crop and Soil Environmental Sciences

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1996

Author dc:creator

• Pridgen, Thomas H.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-10022008-063307

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/44985