Table 10. Changes in nitrogen content in willow chips during storage period (g kg^-1 d.m.)

Cover type		Date
	at harvest	Mar 2011	Jul 2011	Nov 2011	Mar 2012
130	3.85±0.04 e	2.72±0.06 f	4.62±0.98 c	4.23±0.39 d	4.28±0.10 d
200		2.71±0.04 f	3.80±0.04 e	4.16±0.15 d	4.55±0.22 c
Shed		3.06±0.15 e	4.37±0.17 d	4.19±0.11 d	4.55±0.36 c
Foil		2.85±0.05 e	4.48±0.23 c	3.33±0.11 e	5.51±0.66 b
Uncovered		2.95±0.01 e	5.14±0.97 b	6.33±1.87 a	6.67±0.12 a
Mean	3.85±0.04 c	2.86±0.16 d	4.48±0.73 b	4.45±1.29 b	5.11±0.96 a