Stasinievych O. Impact of long-term fertilizers application in crop rotation on the fertility of podzolic black soils in the Right Bank Forest Steppe in Ukraine, on yield and the quality of spring barley varieties

The thesis covers the results of the impact of long-term (40-year period) application of organic and mineral fertilizers on crop rotation productivity and change of soil fertility indicators (complex evaluation of soil fertility was conducted on field trials). On the basis of the analysis of relevant literature as well as the research conducted, a model is identified for complex evaluation of the fertility rate of podzolic black soils in field crop rotation. SICG methodology is considered to be the most suitable and it is based on the studies of the indicator of integrated soil score (ISS) which includes the following: humus content in topsoil; soil acidity; nitrogen, available phosphorus and potassium content; and total alkali absorbed by the soil (base saturation degree). The results of the studies related to the impact of long-term application of fertilizers in crop rotation, weather conditions and biological characteristics of a variety on the yields of spring barley varieties are presented. It isfound out that when high rates of fertilizers (manure 13.5 t/ha + N67P101K54) are applied in field crop rotation, on average during a 3-year period the following yields of spring barley varieties are achieved: Hetman - 4.7 t/ha, Myronivsky-92 - 4.54, Tolar - 4.53, Nevada - 4.28 and Zvershennia - 4.16. The application of the equivalent amount of mineral fertilizers reduces the yields by 13-20% depending on the variety. Regarding malting spring barley, when the low-rate organic and mineral system of fertilization (manure 4.5 t/ha + N22.5P34K18) is used in field crop rotation, Hetman variety produces high yields of suitable quality. An assessment of the efficiency of spring barley production under the conditions of long-term application of fertilizers in crop rotation is conducted. It is recommended to select a variety for an individual field taking into account soil fertility rate and purposes of grain use.