The effect of sulphur fertilization on yield, quality of protein and baking properties of winter wheat
¹Department of Plant Sciences, Estonian Research Institute of Agriculture, Teaduse St. 13,EE75501 Saku, Estonia; e-mail: firstname.lastname@example.org
²Agricultural Research Centre, Teaduse St. 4/6, EE75501 Saku, Estonia
The present paper is based on the data of field and production trials conducted in the years 2004–2007. The trials were carried out in North-Estonia (59° 18’ N, 24° 39’ E) on break-stony soil and in South-Estonia (58° 27’ N, 25° 36’ E) on pseudopodzolic soil. The aim was to identify the effect of sulphur fertilization on the yield of winter wheat (Triticum aestivum L.) on some of the quality indices of yield and protein quality, including the content of non-replaceable amino acids, and on the baking properties of flour. In the field trials the effect of N and NS fertilization was compared on the nitrogen background of N60 + N40 kg ha-1. Due tosulphur (in two top dressings in total S10 kg ha-1) the yield of winter wheat ‘Lars’ increased,depending on the weather and soil conditions, in field trials 0.47–1.48 t ha-1, i.e. 7.7–43.0% and in production trials 1.35–2.44 t ha-1, i.e. 39.8–45.5%. The effect of sulphur on the protein and wet gluten contents of wheat grain was not always one-directional, but in all trials the gluten index increased and the quality of protein improved under the influence of sulphur. Sulphur fertilization increased the content of amino acids in the protein of winter wheat in field trials on the average as following: cysteine – 24.5%, methionine – 35.3%, threonine – 14.4% and lysine – 7.7%. In production conditions the fertilization with sulphur increased both the contents of protein and wet gluten and that of major amino acids. Due to sulphur fertilization all major parameters of winter wheat’s baking quality improved: stability and quality number of dough, loaf volume and specific volume and round loaf’s height to diameter ratio.