The Effect of Organic Fertilisation of Liquid Manure and the PRP Fix Preparation on the Yield and Chemical Composition of Winter Rape Seeds and Spring Wheat Grain

In 2011–2013, a field experiment was carried out at the Experimental Station of Cultivar Evaluation in Szczecin-Dąbie. The experiment aimed at determining the effect of slurry without and with addition of increasing PRP Fix preparation doses on the crop yields and some of their qualitative traits. The soil where the experiment was set up was slightly acidic (pH_KCL 5.95); nitrogen, phosphorus and potassium contents were 0.86, 1.55 and 2.70 g·kg^-1 d.m., respectively. The total content of macro-elements for this type of soil was average. The content of bioavailable forms of phosphorus, magnesium and sulphur was average, while that of potassium was high. The content of organic carbon in soil was low, while the C:N ratio was 10.2:1 and was average for that type of soils. The obtained results show that the applied fertilisation with slurry combined with PRP Fix preparation and PK fertilisation increased the yield of winter rape seeds and spring wheat grain and the content of macro-elements being examined in them. The yields of the test plants were larger in the fertilisation objects where fertilisation with slurry with addition of 8 kg PRP Fix preparation per 1 m³ slurry was applied, when compared to those where only mineral fertilisation or slurry was used. Winter rape seeds and spring wheat grain usually contained more nitrogen, phosphorus, potassium, magnesium, calcium and sulphur in the fertilisation objects being fertilised with slurry with PRP Fix preparation in the amount of 8 or 12 kg per 1 m³ slurry with additional PK fertilisation (experimental series II) compared to experimental series I without additional PK fertilisation. Differences in the content of macro-elements in test plants after application of the fertilisation scheme being used varied. These differences were not always significant.