Milad Mirzaei Aminiyan - Soil Science Department, College of Agriculture, Bu-Ali Sina University, Azadegan Street, Hamedan 517833131, Iran
Ali Akbar Sinegani - Soil Science Department, College of Agriculture, Bu-Ali Sina University, Azadegan Street, Hamedan 517833131, Iran
Mohsen Sheklabadi - Soil Science Department, College of Agriculture, Bu-Ali Sina University, Azadegan Street, Hamedan 517833131, Iran

Introduction Organic carbon (OC) fractions play importantroles in soil and many ecosystem processes. This studyfocuses on changing of OC in density and soluble fractionsin a soil amended by nanozeolite and plant residues thatincubated in lab condition for 90 days.Results The results showed that amounts of OC in lightfraction (LF) and heavy fraction (HF) increased with theincreasing percentage of nanozeolite and plant residues inthe soil. The highest amounts of LF (7.54 g LF. kg-1Soil)and HF (11.10 g kg-1Soil) were found when 30 % nanozeoliteand 5 % wheat and alfalfa straws were added to thesoil. Accordingly, wheat and alfalfa straws were effectiveon increasing the LF and HF, respectively. However, theydecreased with declining the OC from the 1st day ofexperiment until the 90th day of experiment. Soluble OC inhot (2.22 g kg-1Soil) and cool (1.54 g kg-1Soil) water fractionsincreased by addition of 30 % nanozeolite and 5 %plant residues particularly alfalfa straw in comparison withcontrol. Although these soluble fractions increased afterinitial 30 days of incubation, they decreased in the continuationof the experiment.Conclusion In fact, OC contents in density and solublefractions increased by addition of 30 % nanozeolite and5 % plant residues into the soil; however, they decreased ininitial 30 days of incubation with declining the OC. Thefindings of this research revealed the application ofnanozeolite and plant residues improved carbon pools indensity and soluble fractions and carbon sequestrationincreased by increasing OC contents in soil.

Alfalfa straw Wheat straw Light fraction Heavy fraction Hot water Cool water