Bulk soil properties as determinants of the compression strength of puddled lowland paddy soils in Sri Lanka

Abstract

Soil strength/penetration resistance of lowland puddled soil is an important parameter for designing farm machinery. This study was aimed to estimate the overall penetration resistance of lowland puddled soils through the assessment of bulk soil parameters. Penetration resistance and bulk soil parameters including moisture content, bulk density, particle density, porosity, texture and organic matter content were measured under real field condition and evaluated to identify the suitable determinants to explain the variation of soil penetration resistance and their relationships. Results revealed that measured penetration resistance by Eijkelkamp hand penetrometer and bulk soil parameters except particle density, notably varied with weed controlling methods, depth of the soil and the time. Penetration resistance showed a significant relationship with bulk density (BD), moisture content (MC) and porosity (

Bulk soil properties as the determinants of soil surface shear strength of puddled lowland rice soils of Sri Lanka affected by weed controlling methods

“…3, the predicted and measured SS values show higher linear relationships (R 2 =0.695 in T 3 and 0.794 in other treatments). As reported by Eudoxie et al (2012), MC is identified as the determinant of surface soil strength of upland soils and Weerasooriya et al in (2015); MC and BD are identified as the determinants of surface compression strength of low land pudddled soil. These are partially supportive findings to this result.…”

“…Soils are subjected to two kinds of deforming stresses: (a) the normal stress (load) associated with compression and (b) tangential stress causing shear (Bhagat, 2003). Compression strength of the puddled lowland paddy soils in Sri Lanka was evaluated and estimated by Weerasooriya et al (2015), using bulk soil properties as determinants. Though few attempts had been taken to measure the shear strength (SS) (Rathnaweera et al, 2010) no attempt had been made to estimate the SS of lowland puddled paddy soils of Sri Lanka.…”

Relationship between soil moisture deficit and productivity of paddy lands in a major irrigation system in Intermediate zone of Sri Lanka

“…Therefore, the depth of root zone to calculate soil moisture parameters for the soil moisture balance was taken as 25 cm. A recent study has shown that the highest clay accumulation was recorded in 20-30 cm layer in puddled low land paddy soil in Puliyankulama in Anuradhapura (Weerasooriya et al, 2015).…”