Estimation of Optimum Nitrogen Fertilizer Rates in Winter Wheat in Humid Mediterranean Conditions. I. Selection of Yield and Protein Response Models

• Published in: Communications in Soil Science and Plant Analysis Vol. 41; no. 16-19; pp. 2293 - 2300
• Main Authors: Ortuzar-Iragorri, M.A, Castellon, A, Alonso, A, Besga, G, Estavillo, J.M, Aizpurua, A
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis Group 01.01.2010; Taylor & Francis; Taylor & Francis Ltd
• Subjects: Agricultural production; Agronomy. Soil science and plant productions; Biological and medical sciences; Cereal; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; grain protein; N fertilizer; Nitrogen, phosphorus, potassium fertilizations; protein response; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Wheat; yield response; Nitrogen fertilization; Monocotyledones; grain protein; Grains; yield response; Modeling; Cereal crop; Protein; Application rates; Gramineae; Winter crops; N fertilizer; Angiospermae; Humidity; protein response; Cereal; Spermatophyta; Yield; Nitrogen fertilizer; Mediterranean climate; Triticum aestivum
• ISSN: 0010-3624; 1532-2416; 1532-4133
• DOI: 10.1080/00103624.2010.508094

Nitrogen (N) fertilization management directly affects yield and grain protein content of soft red winter wheat, so there is a need to estimate the optimum N fertilizer dose needed to obtain the greatest yield and the desired protein content under a humid Mediterranean climate. The objective of this work was to select the best response models of wheat yield and protein content to applied N fertilizer. To fulfil this objective, 13 experiments were conducted in the years 2001, 2002, 2003, and 2004 in northern Spain where 0, 100, 140, 180, and 220 kg N ha-1 were applied. The quadratic plateau model best described yield response to N fertilizer, with 182 kg N ha-1 producing the maximum yield. The quadratic model was chosen for modeling protein response to N fertilization, and 176 kg N ha-1 was the rate required for achieving protein contents greater than 125 g kg-1.