Grain Yield and Nitrogen Uptake of Maize (Zea mays L.) as Affected by Soil Management Practices and Their Interaction on Cambisols and Chernozem

Table 6

Main effects of tillage, cropping systems, and nitrogen fertilization on soil reaction, organic carbon, total nitrogen, and C : N ratio of the surface layer of soils (0–20 cm).

Treatments	Hawassa Zuria (Cambisols)				Meskan (Chernozem)
	pH	OC (%)	TN (%)	C : N	pH	OC (%)	TN (%)	C : N
Tillage methods
MT	6.1^b	2.61	0.25^a	10.52^b	6.8	4.00	0.36^a	11.31^b
CT	6.2^a	2.59	0.23^b	11.18^a	6.8	3.98	0.33^b	12.14^a
LSD (0.05)	0.06	ns	0.01	0.33	ns	ns	0.02	0.83
Cropping systems
RCS	6.1	2.61	0.25	10.72	6.8	3.99	0.35^a	11.48^b
MCS	6.2	2.60	0.24	10.97	6.8	3.99	0.34^b	11.97^a
LSD (0.05)	ns	ns	ns	ns	ns	ns	0.01	0.37
Nitrogen fertilization
Control	6.0^b	2.51^c	0.21^c	11.84^a	6.6^d	3.83^d	0.32^c	11.94^b
20 t ha^−1 compost	6.3^a	2.68^a	0.24^b	10.73^b	7.0^a	4.11^b	0.32^c	13.02^a
46 kg N ha^−1 +10 t ha^−1 compost	6.2^a	2.66^a	0.26^a	10.19^c	6.9^b	4.14^a	0.39^a	10.57^d
92 kg N ha ^1	6.1^b	2.58^b	0.25^ab	10.63^bc	6.7^c	3.88^c	0.34^b	11.37^c
LSD (0.05)	0.1	0.04	0.01	0.47	0.08	0.03	0.01	0.53

Within the columns, means followed by the same letters are not significantly different at  < 0.05 according to the LSD test.