RESULTS OF FIELD EXPERIMENTS ON WHEAT MINERAL-NUTRITION

The mineral composition of winter wheat, var. Astral, growing in twelve field experimental plots was determined at the tillering, anthesis, and harvest stages respectively. Leaf nitrogen at the anthesis stage was the parameter affected at a greater extent by addition of nutrients. Aerial part weight was also affected though to a lesser extent. No significant differences for potassium and magnesium contents at the tillering and anthesis stages, respectively, were found. Rainfall introduced variability in the results. Nitrogen addition showed the greatest effect on yield increase and on the mineral composition of the plant. The anthesis was shown to be the most important stage in plant nutrition. A discussion on how to achieve optimal nutrition values is made.