Effect of organic residues on soil properties of loamy topsoil of haplic Luvisol in Northern Germany

Abstract

<jats:title>Summary</jats:title><jats:p>The application of organic residues should ensure a sufficient air capacity (AC) and plant available water capacity (AWC) to improve the soil aeration and water supply for plant roots, whereas the air permeability (k<jats:sub>a</jats:sub>) primarily depends on the number of functional and, therefore, connected pores. The objective of the study was to investigate the effect of digestates derived from maize (<jats:italic>Zea mays</jats:italic> L.), sugar beet (<jats:italic>Beta vulgaris</jats:italic> L.), and wheat (<jats:italic>Triticum aestivum</jats:italic> L.) in ratios of 100%, 80%, and 20%, respectively; compost of shrub debris; and sewage sludge on AC, AWC, and k<jats:sub>a</jats:sub> values, including the pore continuity indices (c<jats:sub>2</jats:sub>, c<jats:sub>3</jats:sub>) of a loamy Ap horizon of a haplic Luvisol. The results indicate that AC values increase from 0.142 of up to 0.191 cm<jats:sup>3</jats:sup> cm<jats:sup>−3</jats:sup>, but pore continuities and AWC values decrease from 0.143 down to 0.111 cm<jats:sup>3</jats:sup> cm<jats:sup>−3</jats:sup>, except for wheat-containing digestate (20w80b), which shows an opposite trend. The application of organic residues can compensate low AC values but not the AWC values. The wheat-containing digestate should be preferred for improving the water-holding capacity and, therefore, the water supply for plant roots.</jats:p>