Nitrous oxide emissions and maize yield as influenced by nitrogen fertilization and tillage operations in upland soil

Applied Biological Chemistry

Table 5 Soil bulk density during growing season of maize with different tillage operations (T), nitrogen fertilizations (N), and years (Y)

Year	Year 1			Year 2			Y mean¹
Tillage operations	CT	NT	T mean	CT	NT	T mean	CT	NT	T × Y mean²
Nitrogen fertilizations				Bulk density (g cm⁻¹)
WOU	1.16^b (0.01)	1.38^a (0.07)	1.27^A (0.05)	1.14^b (0.07)	1.36^a (0.09)	1.25^A (0.06)	1.15^b (0.03)	1.39^a (0.06)	1.26^A (0.04)
WU	1.20^b (0.12)	1.40^a (0.09)	1.30^A (0.07)	1.18^b (0.08)	1.38^a (0.09)	1.28^A (0.06)	1.19^b (0.06)	1.37^a (0.05)	1.29^A (0.05)
N mean³	1.18^b (0.05)	1.39^a (0.05)		1.16^b (0.05)	1.38^a (0.06)		1.17^b (0.03)	1.38^a (0.04)
T × N mean⁴	1.29^a (0.05)			1.27^a (0.05)

Standard error in brackets. Different lower- and upper-case letters denote significant differences at p < 0.05 in column and row comparisons, respectively
¹Y mean: mean value across years
²T × Y: mean value across tillage operations and years
³N mean: mean value across N fertilizations
⁴T × N: mean value across tillage operations and N fertilizations