Acta Univ. Agric. Silvic. Mendelianae Brun. 2012, 60, 91-96

https://doi.org/10.11118/actaun201260010091
Published online 2013-10-05

Digestate is equal or a better alternative to mineral fertilization of kohlrabi

Tomáš Lošák1, Ludmila Musilová1, Andrea Zatloukalová1, Monika Szostková1, Jaroslav Hlušek1, Jiří Fryč2, Tomáš Vítěz2, Martin Haitl2, Eduardo von Bennewitz3, Anna Martensson4

1Ústav agrochemie, půdoznalství, mikrobiologie a výživy rostlin, Mendelova univerzita v Brně, Zemědělská 1, 613 00 Brno, Česká republika
2Ústav zemědělské, potravinářské a environmentální techniky, Mendelova univerzita v Brně, Zemědělská 1, 613 00 Brno, Česká republika
3Department of Agronomy, Universidad Católica del Maule, Casilla 7-D, Curicó, Chile
4Department of Soil and Environment, Swedish University of Agricultural Sciences, Ulls väg 17, Ultuna, SE 756 51 Uppsala, Sweden

In a one-year vegetation pot experiment, we compared the effect of digestate from a biogas station and mineral fertilisers on yield and quality parameters of kohlrabi, variety Segura F1. Four treatments were used in the trial: 1) untreated control, 2) urea, 3) digestate, 4) urea, triple super phosphate, KCl, MgSO4. The N dose was the same in treatments 2–4, 1.5 g N/pot. In treatment 4 the P, K and Mg doses corresponded to those supplied in the digestate treatment (3).
The weight of single kohlrabi bulbs in the unfertilised control was significantly lower (36.2%) than in the urea treatment (100%) and the other fertilised treatments. After application of digestate (treatment 3) and mineral fertilisers (treatment 4), the weight of single bulbs significantly increased by 36.2 and 33.6%, respectively, compared with the urea treatment (2). The content of ascorbic acid did not differ between the fertilised treatments (282–301 mg/kg), but was significantly lower than in the unfertilised control (334 mg/kg). There were significant differences between all fertilised treatments (2, 3, 4) in bulb nitrate content (745, 187, 462 mg NO3/kg fresh matter, respectively). After digestate application the content decreased significantly, to 187 mg NO3/kg fresh matter. The soil Nmin content after harvest varied between 4.19–5.79 mg/kg in all fertilised treatments and the N-NH4+ form prevailed over N-NO3 only in the digestate treatment (3.45/2.34 mg/kg). We recommend the use of digestate to kohlrabi as it results in comparable or better yield and qualitative parameters of kohlrabi compared with mineral fertilizers.

References

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