Case Study on High and Medium Yielding Perennial Energy Crops, Miscanthus × Giganteus Anders. and Elymus Elongatus (Host) Runemark, 10-years Cultivation Impact on Main Soil Chemical Properties

Abstract

The aim of the research was to determine the effect of 10 years of growing the perennial energy grasses giant silvergrass (GS) and tall wheatgrass (TW) on the content of main soil nutrients, under differentiated nutrition intensity. The following nutrition treatments were monitored: intensive 120 kg/ha N per year (T1), semi-intensive 60 kg/ha N per year (T2), and untreated control (T3), whereby on both treatments T1 and T2 a dose of 30 kg/ha P and 30 kg/ha K was applied before the establishment of crop stands. The small-plot experiment was conducted in soil-climatic conditions of the East Slovak Lowland on heavy Fluvic gleysol in 2013. Over the monitored 10-year period, the cumulative dry matter yield was 266.6; 212.9; 163.2 t/ha at GS, in the order of T1-T2-T3, and 120.5; 96.6; 70.2 t/ha at TW, respectively. The change status (final state of autumn 2022 vs. initial of autumn 2012) of soil main chemical parameters (total nitrogen, and available phosphorus, potassium, magnesium, and calcium content; exchange soil reaction; organic carbon and humus content; and carbon/nitrogen ratio were followed) was crop specific in general, as strongly influenced by the nutrition intensity and by crop cumulative yield as well. Total nitrogen content in soil was changed as follows: +216; +167; +207 kg/ha at GS, and +306; +230; +90 kg/ha at TW, in the order of T1-T2-T3, while soil organic carbon content: +2.036; +1.883; +1.631 t/ha at GS, and +2.743; +2.104; +1.105 t/ha at TW, respectively. The change status of further parameters was positive/negative in ratio of 17/19, thus 29/19 in total.