Influence of different potassium fertilization level on nutritional status of winter wheat and on yield during critical growth stage
Wydanie: 4 / 2010
An optimum plant crop nutrition status during critical stages of growth is one of the most important factors shaping their ability to yield. It has been assumed that plant nutrition during the spring wheat stem elongation stage has a significant influence on the growth and yield of this crop. In Poland, potassium is a critical nutrient for plant growth and yielding. In order to verify this hypothesis, three series of one factorial experiment were conducted in 2003-2005 that involved reduced rates of potassium applied to cv. Zyta winter wheat. The following rates of potassium were applied: 0, 25, 50 and 100 kg ha-1. The assessment of wheat nutritional status was conducted at the beginning of stem elongation (BBCH30/31) using a German model called PIPPA. It had been hypothesized that this particular stage was decisive for wheat growth and yielding. Wheat plants showed deficiency in Ca, K, P and N irrespective of the applied potassium rate. Calcium and potassium deficiencies were crucial for the final grain yield. However, the relationships that occurred between nitrogen and main nutrients, i.e. pairs of nutrients such as N:P, N:K, N:Ca, showed a much better prognostic value, i.e. the relationship with grain yield, than the levels of nutrients in separation. The nitrogen content in leaves at the beginning of shooting showed its limiting effect on grain yield, provided that Ca was deficient, an event which appeared when N:Ca was wider that 34:1. The same correlation was noticed for potassium, but there the excess of nitrogen revealed its harmful effect when the N:K ratio was above 1.0.
Gaj R. 2010. Influence of different potassium fertilization level on nutritional status of winter wheat and on yield during critical growth stage. J. Elem. 15(4):629-637.
Słowa kluczowe:winter wheat, potassium rate, nutritional status, the beginning of shooting