InteractiveEffects of Organic Matters and Earthworm on some Physical and chemical Properties of Two Soils under Different Compaction Conditions

Although it has been known that earthworms through feeding, casting, and burrowing activity can influence soil physical and chemicalproperties, but interactive effects of organic matters and earthworm on aggregationunder different compaction and textural conditions, have been not wellknown. In thisstudy, the interactiveeffects of earthworm Eisenia fetida and organic matters on some physical and chemical properties of two fine- and coarse-textured soils selected from Moghan plain, northwest of Iranwere investigated in two compaction level. The factorial experiment was conducted asa completely randomizeddesignwith 24 treatments and 3 replicates under growth room conditions during 6 months. The 4 factors were: 2 soil textural classes (sandy loam and clay loam), 3 organic matter levels (0, 20 g kg-1 of wheat straw and cow manure), 2 soil compaction levels (1.3 and 1.45 g/cm3) and with or without earthworm. The results showed that on average, both used organic matters significantly increased organic carbon (OC) (by 69%), soluble Ca (by 11.75%), meanweight diameter (MWD) of aggregates (by 78%)and decreased bulk density (by 3.6%)in two soils. Also, the positive effects on the soil structure were much observed in the straw and clay loam with earthworm treatment due to the high contents of OC, Ca, Mg and clay.soil with earthworm in compaction level of 1.45 g/cm3, significantly increased MWD by 10 and 16.6% and total porosity by 5.6 and 6% in sandy loam and clay loam soils, respectively. Theresults indicated that application of earthworm to the compacted soilscan improve physical quality of fine- and coarse-textured soils by using minimum organic matter.