Monitoring N : P Ratio and Cd, Cu, Pb, and Zn Contents in Different Types of Anaerobic Digestates: A Six-Year Study Case

Table 2

Range of total N and P contents and pH of five digestates and cattle slurry (analyzed twice a year over six years; therefore, n = 12 (DG Mix liquid five years, n = 10), and different letters within columns mark significant differences between means (Scheffé’s test, )).

	N (% FM)	N (% DM)	P (% FM)	P (% DM)	pH
DG Pig	0.2–0.5^a	4.7–11.3^c	0.01–0.15^a	0.5–2.1^b	7.4–8.2^b
DG Cattle	0.4–0.5^b	5.5–8.2^c	0.04–0.09^a	0.6–1.3^ab	7.6–8.3^bc
DG Renew	0.4–0.6^c	4.6–9.5^c	0.05–0.18^a	0.6–1.6^ab	7.8–8.4^c
DG Mix solid	0.5–0.6^c	1.9–2.9^a	0.11–0.26^b	0.5–1.1^a	8.5–9.3^d
DG Mix liquid	0.3–0.6^b	6.1–11.3^c	0.03–0.08^a	0.6–1.2^ab	7.3–8.4^bc
Cattle slurry	0.3–0.4^a	3.7–4.8^b	0.03–0.09^a	0.4–1.1^ab	6.4–7.4^a