engleski

Effect of digestate fertilization on the silage maize yield and the load of heavy metals in maize

Maize is one of Croatia’s largest single commodities with a production of 2147275 t in 2018, which was produced on approximately 235352 ha. Mostly it is produced for grain (harvest time), but it is also used as a fresh (dent stage) animal feed or as a feedstock for biogas production. Nowadays fertilization with synthetic fertilizers can led to several issues such as high cost and nitrate pollution. Digestate, as a byproduct of anaerobic digestion (AD), might have a potential to be used as an alternative fertilizer for sustainable agriculture. Therefore, this study aimed to: i) assess the use of digestate as a fertilizer and its effect on silage maize yield, and ii) determine the heavy metal accumulation in the plant. This was done in a field experiment in Croatia during one growing season where eight different treatments (i. solid fraction of digestate (SFD), ii. liquid fraction of digestate (LFD), iii. NPK fertilizer (with top dressing of CAN), iv. liquid cattle manure (LCM), v. SFD+LFD, vi. LFD+NPK, vii. SFD+NPK and viii. unfertilized control (C)) in four repetitions were compared and assessed. Results have shown significant differences (p<0.05) among the treatments regarding the maize yield. Te highest average yield was observed in NPK+CAN, SFD+NPK, LFD+NPK, SFD and SFD+LFD treatments, whereas unfertilized C resulted in lowest yield. Furthermore, heavy metal content in plant for Zn (50 mg kg-1) and Cu (20 mg kg-1) did not exceed the permitted limit concentration, whereas in NPK+CAN, SFD+NPK and LFD+NPK treatments the exceedance for Mn (30 mg kg-1) occurred. Digestate derivatives, LFD and SFD, showed similar effect on yield as compared to NPK+CAN treatment. This might lead to economic benefits by reducing consumption of expensive synthetic fertilizers.

silage maize, digestate, yield, heavy metals in plant

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