Agriculture Reference
In-Depth Information
Figure 2. C
4
-C from corn and C
3
-C in soil total organic C (a) and in humic acids (b) of control and plots
of corn monoculture treated consecutively over 30 years with mineral fertilizers (Min) and manure
(Org). Bars are standard errors, n = 6 replicates.
Other experiments have also shown either no change or increase in SOC concentration
with N fertilization applied to continuous corn production with moldboard tillage (Huggins et
al., 1998; Gregorich et al., 1996).
The effect of manure addition in the Org treatment was even more pronounced than the
mineral fertilization alone and also in this case the better effect on SOC concentration was
