Effect of different mowing intensities on phytomass production of permanent grassland in a warm and an arid region

Abstract

The aim of the work was to analyse the impact of different intensities of grassland exploitation on the productive capacity in the context of declining livestock numbers and the need for temporary or permanent extensification. The research was carried out in 2017–2020 in the locality of Žirany in the Nitra district, located in the temperate zone at the boundary between the continental and Atlantic-continental regions. Average annual temperatures are around 9 °C. The original semi-natural vegetation has been used for sheep grazing for many years. There were 8 experimental variants of use/cutting with different intensity of exploitation: var. 1 – abandoned unused, var. 2 – 3 × per year, var. 3 – 2 × per year, var. 4 – 1 × per year, var. 5 – 4 × – 3 × – 2 × – 2 × – 1 × per year, var. 6 – 1 × – 2 × – 3 × – 4 × per year, var. 7 – 3 × – 1 × – 1 × – 3 × and var. 8 – 2 × – 1 × – 1 × – 1 × – 2 × . By comparing the sum of yields for the entire 4-year annual cycle, we concluded that, with the exception of the 1 × annually mowed variant, all the others differentiated themselves from the abandoned stand by their increased production capacity. We also observed differentiation between fertilized and exploited variants into groups. The stand mowed 3 times annually (variant 2, 29.07 t/ha) was shown to be the most productive. The second group consisted of variants with production lower in the sum of 4 years by about 5 t/ha (3, 5, and 6). The same level of lower yield was then found on stands with temporarily reduced intensity of use (variants 7 and 8). In the effectiveness of applied nutrients on production growth, it was found that as the number of applications increased, nutrient use also increased. The average of the years in the overall assessment of the 4-year cycle showed the dynamics from the individual years and also confirmed the tendency of the highest nutrient use at a stable 3-cut use.