Abstract:
In this study, effects of rice husk (RH) application on mechanical properties and cultivation of a clay textured
soil were investigated with and without barley planting. A rate of 5% (w/w) rice husk as a dry weight basis was
added to a clay textured soil by alone (RH) and with 5 kg N/da of ammonium sulphate (RHN) in order to
increase the biological activity and the decomposition rate of rice husk in soil. Rice husk applied soils including
control treatment were incubated at field capacity under greenhouse conditions for 2 months. After this period,
barley was sown in a half number of the pots. All pots having barley planted and without planted were incubated
together for 6 more months. Study was carried out in a factorial experimental design on barley planting and
without planting pots in 3 treatments (control, RH and RHN) with 3 replications. At the end of the study, liquid
limit (LL), plastic limit (PL), plasticity index (PI), consistency index (Ic), field capacity (FC), permanently
wilting point (PWP) and organic matter (OM) contents of soils were determined. The highest values were
determined for LL in RH+nitrogen+barley planting (RHNP), for PL in RH application without planting and for
PI in control application with barley planting (CP). Barley planting increased LL and PI values of soil
significantly. LL values of soils significantly correlated with PL (0.664**), PI (0.880**) and PWP (0.948**). PL
values of soils significantly correlated with OM (0.699**) and PWP (0.821**). PI values of soils significantly
correlated with FC (0.654**) and PWP (0.713**). Ic values gave the significant correlations with PL (0.908**),
OM (0.787**), FC (-0.611**) and PWP (0.615**). Ic values in all RH treatments were higher than that in
control treatments. It was concluded that clay textured soil in control treatment can have deformation when it is
cultivated at the field capacity without RH application; however clay soils can be cultivated without deformation
after application of RH.
