Effect of rate of copper application on yield of hard red spring wheat

• Published in: Communications in soil science and plant analysis 2005-01, Vol.35 (13-14), p.2037-2047
• Main Authors: Karamanos, R.E, Goh, T.B
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; application rate; Biological and medical sciences; copper fertilizers; copper sulfate; fertilizer application; Fundamental and applied biological sciences. Psychology; grain yield; hard red spring wheat; prairie soils; seed productivity; Triticum aestivum
• ISSN: 0010-3624; 1532-2416
• DOI: 10.1081/LCSS-200026834

Broadcast and incorporation of CuSO4·5H2O at a minimum rate of 4 kg Cu ha-1 is a recommended method of correcting Cu deficiency in prairie soils. Very little research has been carried out to ascertain whether near maximum yields can be obtained with lower Cu rates, especially because the cost of this practice is normally very high. Furthermore, no research has been carried out to examine the impact of overapplication of this product. Two experiments were carried out in 1999 and 2000 to address these two issues, one with 4 rates of Cu (0, 1, 2, and 4 kg Cu ha-1) and one with 12 rates (0, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 kg Cu ha-1) in the form of CuSO4·H2O. A total of 16 trials were carried out with hard red spring wheat on two groups of soils, namely, one containing soils that are considered Cu deficient (0.4 mg DTPA-Cu kg-1). There was a significant wheat seed yield increase to Cu fertilization in deficient soils only with the application of up to 5 kg Cu ha-1. Near maximum yields were obtained with application of 2 kg Cu ha-1, thus providing a more economic alternative to prairie producers. Application of rates greater than 5 kg Cu ha-1 led to a gradual yield reduction and at 10 kg Cu ha-1 as CuSO4·5H2O, the yield was actually lower than that of the control. Hence, overfertilization with CuSO4·5H2O results not only in an economic waste but a danger of toxicity.