YIELD AND QUALITY OF СEREAL GRAINS IN RELATION TO P-STATUS OF SOD-POZOLIC LOAMY SAND SOILS AND FERTILIZERS

Abstract

The field experiments with fertilizer treatments of spring wheat, peas and winter triticale on the four different levels of soil supply with mobile phosphates has been conducted in 2005-2009 on luvisol loamy sand soils in Belarus. It was found the spring wheat grain yield linear increase by factor 1.8 and protein yield by factor 1.9 according to change of mobile Р₂О₅ content from 70 to ≈400 mg/kg of fine textured loamy sand soil. While the grain yields of peas and winter triticale were increasing according to quadratic parabolic curve with maximum in the range of Р₂О₅ content 200-400 mg/kg of the coarse textured loamy sand soil. The mobile Р content of soil fitted to maximum crop yield represents the upper level of optimal range while the P content fitted to maximum yield increment per 1 kg of P fertilizer represents the lower level of optimal range. There was found significant increase of protein and gluten contents as well as the improvement of amino acid composition and biological quality of grain proteins according to increase of soil P supply levels up to the optimal range.