Effects of Rates and Nutrient Ratios on Production and Quality of Phytomass at Fertiliser Application to an Alluvial Meadow

The research objective was to assess effects of fertiliser application rates and nutrient ratios on production and quality of grassland at an alluvial meadow. The initial sward type was Festucetum pratense association. A field trial was established in the western part of "Zvolenská kotlina" basin (altitude 350 m) and consisted of ten fertiliser treatments: zero-fertilised sward (control); fertiliser P and K application; rates of 50, 100, 150 and 200 kg N/ha at two ratios of N : P : K nutrients, namely the low N : P : K ratio (1 : 0.3 : 0.8) and the high one (1 : 0.15 : 0.4), respectively. The grassland was utilised by three cuts. Dry matter (DM) production and herbage quality were determined at each of the cuts. The yield of DM was higher with the rates of 50 and 100 kg N/ha applied at the high nutrient ratio than at the low ratio. Over the research period, the highest DM production was recorded at the treatment with the low nutrient ratio and the highest N rate applied. The content of crude protein (CP) was increasing with the rising fertiliser N rate and the increase in CP was higher at the low nutrient ratio treatments. The zero-fertilised control also provided sufficient CP content. The low nutrient ratio resulted in higher P and K content than the high one. The lowest content of P and K was recorded at the control. The highest P content was found at the treatment with the fertiliser P and K applied. The highest K content was recorded at the 2ⁿᵈ cut, but decreased at the 3ʳᵈ cut in all the treatments. The content of Ca was rising towards the 3ʳᵈ cut. The content of nutrients was higher at the treatments where the high ratio was used. The content of Mg in DM was higher at the treatments with the high nutrient ratio and the high N fertiliser rates. The content of Mg was increasing in the 2ⁿᵈ cut at all the treatments.