Studies on the Water Stable Aggregates of Bihar Soils

Different durations of wetting (5 to 50 minutes) did not affect the stability of the aggregates. Longer the duration of shaking greater was the disintegration of the aggregates. Uncultivated soils showed less disintegration due to shaking than the cultivated soils, except in Kanke. Positive correlations were observed between the micro-aggregates and cation exchange capacity, ferric oxide, exchangeable calcium and sodium contents of soils. High aggregation in the alluvial clay soils of Patna was probably due to high clay and cation exchange capacity of the soil. Alluvial soils of Sabour showed low aggregation probably due to low clay and organic matter contents. Higher aggregation in the sandy alluvial uncultivated soils of Pusa than the cultivated soils might be due to the mechanical binding effect of the grass roots. The sedentary red loam soils of Kanke showed high aggregation probably due to its high clay and iron content.