Influence of biosolids application on some soil physical properties

Biosolids land application is a widely accepted option throughout the world because of its beneficial effects on soil chemical and physical properties and crop yield. These effects-e specially those pertaining to soil physical properties-have not been adequately studied in Mediterranean conditions. In a 3-yr field experiment, conducted in a clay loam (Typic Xerochrept) in central Greece, the influence of biosolids application on cotton yield and some physical soil properties was studied. The experimental design was completely randomized blocks with four biosolids rate (0, 10, 30, and 50 ton ha(-1) yr(-1)) and four replicates. We found that after 3 yr of biosolids application, organic matter content, water retention capacity, available water, and infiltration rate significantly increased, whereas bulk density and aggregate instability index decreased. Soil physical properties affected by the SS addition were significantly correlated with organic matter content. Organic matter content was positively correlated with cotton yield, water retention capacity, available water, and infiltration rate and negatively correlated with bulk density and aggregate instability index.