Evaluation of Some Physical Parameters as Puddling Indices in Alluvial Soils of Punjab

Soil physical parameters viz. aggregate size distribution, cummulative settling and per cent change in volume upon puddling were evaluated as puddling indices for seven alluvial soils of Punjab. These soils were puddled in columns to three depths, viz. 5, 10 and 15 cm with two puddling intensities viz. low and high corresponding to energy inputs of 1.5 and 3.0 MJ m−2, respectively. Aggregate size distribution did not explain the decrease in percolation rate especially at high puddling intensity. Cumulative settling was significantly correlated with percolation rate and was found to be a better puddling index for medium to fine textured alluvial soils of Punjab. A field study on a sandy loam soil with three puddling intensities showed that suspension ratio - a measure of cumulative settling, was significantly related to sediment density of the puddled soil and rice yield. Cumulative settling was also correlated with bulk density and clay content but was not correlated to soil organic matter and intensity or depth of puddling. A three variable linear equation with bulk density, clay content and intensity of puddling best described the cumulative settling of soil suspension.