Effects of Application of Recycled Chicken Manure and Spent Mushroom Substrate on Organic Matter, Acidity, and Hydraulic Properties of Sandy Soils

<p>This study aimed at examining the effects of long-term application of<br> chicken manure (CM) and spent mushroom substrate (SMS) on organic matter accumulation, acidity,<br> and hydraulic properties of soil. Two podzol soils with sandy texture in Podlasie Region (Poland)<br> were enriched with recycled CM (10 Mg ha􀀀1) and SMS (20 Mg ha􀀀1), respectively, every 1&ndash;2 years<br> for 20 years. The application of CM and SMS increased soil organic matter content at the depths<br> of 0&ndash;20, 20&ndash;40, and 40&ndash;60 cm, especially at 0&ndash;20 cm (by 102&ndash;201%). The initial soil pH increased in<br> the CM- and SMS-amended soil by 1.7&ndash;2.0 units and 1.0&ndash;1.2 units, respectively. Soil bulk density at<br> comparable depths increased and decreased following the addition of CM and SMS, respectively.<br> The addition of CM increased field water capacity (at &ndash;100 hPa) in the range from 45.8 to 117.8%<br> depending on the depth within the 0&ndash;60 cm layer. In the case of the SMS addition, the value of the<br> parameter was in the range of 42.4&ndash;48.5% at two depths within 0&ndash;40 cm. Depending on the depth, CM<br> reduced the content of transmission pores (&gt;50 m) in the range from 46.3 to 82.3% and increased the<br> level of residual pores (&lt;0.5 m) by 91.0&ndash;198.6%. SMS increased the content of residual pores at the<br> successive depths by 121.8, 251.0, and 30.3% and decreased or increased the content of transmission<br> and storage pores. Additionally, it significantly reduced the saturated hydraulic conductivity at<br> two depths within 0&ndash;40 cm. The fitted unsaturated hydraulic conductivity at two depths within the<br> 0&ndash;40 cm layer increased and decreased in the CM- and SMS-amended soils, respectively. The results<br> provide a novel insight into the application of recycled organic materials to sequester soil organic<br> matter and improve crop productivity by increasing soil water retention capacity and decreasing<br> acidity. This is of particular importance in the case of the studied low-productivity sandy acidic soils<br> that have to be used in agriculture due to limited global land resources and rising food demand.</p>