Agriculture Reference
In-Depth Information
Figure 1. δ
13
C ‰ values of soil total organic C (a) and of humic acids C (b) of control and plots of both
monocultures treated consecutively over 30 years with mineral fertilizers (Min) and manure (Org).
With the two treatments, on the contrary, and especially with the Org one, the lower
proportion of corn-derived C in HA compared to that of SOC suggests that no preferential
storage of new C input through immobilization in HA was induced by these treatments. This
different behaviour of the new C
4
-C depending on the treatments is further confirmed by
relating the amount of corn-derived C measured in HA to the total corn-derived C in SOC.
This relationships gives evidence that in the control about 40% of the total new C
4
-derived C
in SOC was in the HA fraction, 38% was measured with the Min treatment, whereas 35% was
found in the Org one.
