The effect of fertilisation with fermented pig slurry on the quantitative and qualitative parameters of tomatoes (Solanum lycopersicum)

The effect of fertilisation with fermented pig slurry on the quantitative and qualitative parameters of two kinds of tomatoes was assessed by means of pot trials. These trials were carried out between the years 2005 and 2008. Each trial involved four treatments, namely (a) control without fertilisation, (b) fertilisation with mineral fertilisers, (c) 50% nutrients in mineral fertilisers and 50% in fermented pig slurry, and (d) fertilisation with fermented pig slurry only. Besides the yield parameters, the following characteristics were monitored: dry matter content, vitamin C content, titratable acidity, nitrogen compounds, nitrates and selected elements (Pb, Cd, As, Zn and Hg) contents. The fertilisation method showed no statistically significant influence on many parameters (titratable acidity, Hg, As, dry matter, vitamin C and nitrates contents). These results showed that anaerobically fermented pig slurry can be a suitable alternative to the use of mineral fertiliser. They also showed that its use as an organic fertiliser did not impair the hygienic quality and safety of the vegetable products grown, as all tomato samples fulfilled the tested heavy metals and nitrates legislation limits. The fertilisation method showed a statistically significant influence on the yield. Diffe-rences occurred between the organic and mineral methods in the case of Cd, and between non-fertilised and organic methods in the case of Zn. The fertilisation method also significantly influenced N-compounds content in tomatoes. A statistically significant influence of the year was found with all parameters except zinc and vitamin C contents. The influence of cultivar was also found, but only in the case of zinc and dry matter contents.