Premium
Effect of topdress nitrogen rates applied based on growing degree days on winter wheat grain yield
Author(s) -
Dhillon J.S.,
Raun W.R.
Publication year - 2020
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.1002/agj2.20265
Subject(s) - randomized block design , grain yield , growing degree day , nitrogen , agronomy , growing season , winter wheat , yield (engineering) , mathematics , factorial , degree (music) , nutrient , winter season , biology , zoology , phenology , chemistry , geology , materials science , mathematical analysis , ecology , physics , organic chemistry , climatology , acoustics , metallurgy
The majority of in‐season nutrient management decisions for numerous crops are based on subjective morphological scales. The objective of this study was to establish whether a numerical scale based on growing degree days (GDDs > 0) utilizing weather science, could be used for N management in winter wheat ( Triticum aestivum L.). An incomplete factorial within a randomized complete block design (RCBD) was replicated three times, over a period of three growing seasons (2017−2019). The locations were Efaw near Stillwater, OK; and Perkins, OK. A total of 15 treatments were included where three treatments received pre‐plant N rates of 0, 90, and 120 kg N ha −1 ; and remaining treatments received topdress N of 30, 60, and 90 kg N ha −1 at 65, 80, 95, and 110 GDDs. Data collection included grain yield, grain protein concentration, and N uptake. Topdress application of N at 80−95 GDDs resulted in improved grain yields at 3 out of 6 site‐years. Grain protein concentration increased when N was applied topdress (90 kg N ha −1 ) at 110 GDDs (3 out of 6 site‐years). This work shows that an easier‐to‐use‐numerical‐scale based on GDDs (80−115) could be utilized for efficient topdress N application in winter wheat.