Assessment of changes in different fractions of the organic carbon in a soil amended by nanozeolite and some plant residues: incubation study

Organic carbon (OC) fractions play important roles in soil and many ecosystem processes. This study focuses on changing of OC in density and soluble fractions in a soil amended by nanozeolite and plant residues that incubated in lab condition for 90 days.

The results showed that amounts of OC in light fraction (LF) and heavy fraction (HF) increased with the increasing percentage of nanozeolite and plant residues in the soil. The highest amounts of LF (7.54 g LF. kg-1 Soil) and HF (11.10 g kg-1 Soil) were found when 30 % nanozeolite and 5 % wheat and alfalfa straws were added to the soil. Accordingly, wheat and alfalfa straws were effective on increasing the LF and HF, respectively. However, they decreased with declining the OC from the 1st day of experiment until the 90th day of experiment. Soluble OC in hot (2.22 g kg-1 Soil) and cool (1.54 g kg-1 Soil) water fractions increased by addition of 30 % nanozeolite and 5 % plant residues particularly alfalfa straw in comparison with control. Although these soluble fractions increased after initial 30 days of incubation, they decreased in the continuation of the experiment.

In fact, OC contents in density and soluble fractions increased by addition of 30 % nanozeolite and 5 % plant residues into the soil; however, they decreased in initial 30 days of incubation with declining the OC. The findings of this research revealed the application of nanozeolite and plant residues improved carbon pools in density and soluble fractions and carbon sequestration increased by increasing OC contents in soil.