EFFECT OF NITROGEN FERTILIZERS ON THE STRUCTURE OF YIELD AND GRAIN YIELD OF SWEET SORGHUM DEPENDING ON THE AVAILABILITY OF SOIL PHOSPHORUS

Abstract

The results of two years of research have shown that the application of nitrogen fertilizers in top dressing against the background of different availability of soils with mobile phosphorus had a significant effect on the change in crop structure and on the yield of sweet sorghum. It is shown that the yield of grain in varieties of sweet sorghum increased on fertilized variants from 13.6 to 42.9 %.The highest grain yields (39.7 c/ha in the Kazakhstanskoye grade 16 and 45.6 c/ha in the Kazakhstan 20 grade) were obtained on backgrounds with increased soil availability by mobile phosphorus. The excess over the control variant was: on the height of the plants - 14.7 17.1 % for the variety Kazakhstan 16 and 10.9-12.4 % for the grade Kazakhstan 20; for raw biomass, respectively, 14.3-24.8 % and 15.0-23.7 %, and by weight of 1000 grains, respectively, 22.8-29.3 % and 12.3-28.8 %.The results obtained two years of research showed that the application of nitrogen fertilizers in the fertilizer on the background of various security of soil phosphorus had a significant effect on the change in the structure of crops and grain yield of sweet sorghum.