Changes in the Nutritional Value of Timothy (Phleum pratense L.) Biomass as a Response to Varied Organomineral Treatment

Abstract

The aim of the experiment was to determine the impact of the interaction of slurry with soil conditioners used in organic farming on selected feed parameters of Phleum pratense biomass. The research was conducted in three replications at the experimental facility of Siedlce University (52°10′03"N; 22°17′24"E, Poland) in years 2015 - 2017. The fertilizers used in the experiment were cattle slurry used separately and supplemented with leonardite extract and vermicompost extract, as well as mineral NPK. Cattle slurry was used each year at a total dose of 30 m3 ha-1, divided into individual cuts. Soil conditioners were used in accordance with the manufacturer's recommendations. NPK mineral fertilization was applied at doses: N – 100, P – 30, K – 100 kg ha-1. The tested plant in the experiment was forage grass of the species Phleum pratense of the Secesja variety. The content of the neutral detergent fiber fraction and acid detergent fiber fraction was analyzed in the plant material samples using near-infrared reflectance spectroscopy (NIRS). The relative nutritional value was determined based on the neutral and acid detergent fiber fraction content. It was shown that the addition of vermicompost and NPK extract to the slurry improved the values of the tested parameters compared to the slurry alone. The feed value of biomass collected from facilities fed with slurry and NPK was higher than the feed value of biomass fertilized with slurry with leonardite extract, but comparable to the value of biomass fertilized with slurry supplemented with vermicompost extract.