Fine‐Tuning Nitrogen Fertilization Strategies for Wheat: Unraveling Grain Yield and Protein Concentration Dynamics Across Diverse Agroclimatic Conditions

Abstract

A big proportion of the wheat‐planted area is managed with blanket recommendations, meaning that N rates are recommended as a recipe without considering previous diagnosis or environmental conditions of the site and the year. The objectives of this work were to (1) quantify the response of grain yield and grain protein concentration to nitrogen fertilization and identify the key environmental predictors behind these responses, and (2) evaluate the role of foliar nitrogen applications on wheat yield and protein concentration under different environmental conditions in central Santa Fe province. Data were collected from 15 nitrogen fertilization experiments conducted during the 2015 and 2016 growing seasons. Treatments included nine nitrogen levels from 0 to 200 kg ha −1 , each level with and without foliar fertilization in the pre‐flowering stage (0 or 20 kg ha −1 ). Increases in yield due to nitrogen fertilization were evident in most trials, but the magnitude of the responses was site‐specific. Soil nitrogen at sowing and the photothermal quotient during the month of September were associated with the response of yield to nitrogen rates, whereas in the case of protein sowing date, organic matter, and photothermal quotient during the month of September were associated with its response to nitrogen rates. These results highlight the relevance of previous diagnosis as well as the environmental conditions for fine‐tuning nitrogen management in wheat cropping systems. Results can also be leveraged to develop more profitable and sustainable fertilization practices, enhancing wheat productivity and protein concentration not only in the Argentine Pampas but also in similar wheat production systems globally.