Effect of digestate on soil microelement

After the application of the digestate in 5 and 10 L ha-1 dosages, the Cd, Co, Cu, Ni and Sr content of soil solutions did not change. The Zn content decreased significantly, while the amount of manganese (Mn) increased by almost 40% (Vago et al., 2009) (Table 5).

Element

Control

5 L ha-1 digestate

10 L ha-1 digestate

Cd

0.063

0.067

0.055

Co

0.064

0.071

0.057

Cu

0.089

0.112

0.118

Mn

25.5

35.1

35.5

Ni

0.50

0.52

0.35

Sr

8.56

8.60

8.62

Zn

1.40

0.98

0.062

Table 5. Microelement content of soil samples (mg kg-1) treated with liquid digestate (extraction with 0.01 M dm-3 CaCO3). (Data from Vago et al., 2009).

The increasing soluble P content of digestate treated soil decreased the available Zn content in the soil solution by building slightly soluble zinc-phosphate residue (Vago et al., 2009).