TABLE 1.

Annual input rates of manure and chemical fertilizers in the different treatments.

Treatment	Pig manure*	Urea	Superphosphate	Potassium chloride
	kg hm–2 (dry weight)	kg hm–2	kg hm–2	kg hm–2
CK	0	0	0	0
N	0	300	0	0
NP	0	300	120	0
NPK	0	300	120	75
M	4000	0	0	0
MN	5500	300	0	0

*Fresh manure was applied as a basal fertilizer to agricultural soil before wheat sowing every year (early October).