Effect of Mineral Nutrition on winter wheat Yield after Sunflower in Ukrainian Steppe Zone
The results of the long-term researches on determination of the effect of mineral fertilizers on the winter wheat yield after sunflower in the steppe zone of Ukraine are presented. The high efficiency of complete mineral fertilizer (N90P60K60) application in pre-sowing cultivation that provides 2.29 t/ha increase in yield in comparison with control (without fertilizers) is established. N60P60K60 norm of fertilization before sowing is also relevant especially in the case of optimal weather conditions and subsequent fertilization of crops with nitrogen. At the same time, the increase of applied nitrogen share up to N120-180 as part of complete fertilizer does not lead to a significant yields increase compared to other variants, and in some years, in particular, it can even cause the yield decrease in drought conditions during grain swelling and formation. It has been proven that winter wheat sowing without any fertilizers application or applying small amount of fertilizers before sowing (N16P16K16 та N30P60K60) eventually causes a significant reduction in yield compared to better variants. In most cases that cannot be compensated by nitrogen fertilization in the first part of spring-summer vegetation.