THE EFFECT OF THE PREVIOUS CROP AND DIFFERENTIATED FERTILISATION ON YIELDS AND CONTENT OF N-SUBSTANCES IN SPRING BARLEY GRAIN

HŘIVNA, L., RICHTER, R., RYANT, P., PŘIKOPA, M.: The eff ect of the previous crop and diff erentiated fertilisation on yields and content of N-substances in spring barley grain. Acta univ. agric. et silvic. Mendel. Brun., 2009, LVII, No. 5, pp. 141–148 In small-plot experiments established in 2001–2004 we studied the eff ect of the chemical composition of the plant dry matter of spring barley, varieties Kompakt and Jersey, on grain yields. A re la tive ly strong correlation was confi rmed between the chemical composition of the plant dry matter and yields. The correlation was most intensive in the case of nitrogen (r = 0.536), phosphorus (r = 0.503), magnesium (r = 0.464) and sulphur (r = 0.431) at the beginning of shooting (DC 30); in the case of potassium (r = 0.557) at the beginning of tillering (DC 23) and calcium (r = 0.530) during ear formation (DC 55). A relatively strong correlation remained from the beginning of tillering to the beginning of ear formation and later decreased. The weather conditions of the year and variety signifi cantly affected grain yields and also the previous crop was important. Grain yields of the variety Kompakt were statistically signifi cantly lower than of the variety Jersey (6.02 t . ha −1 and 6.45 t . ha −1 , respectively).