Soil organic matter, texture, and drying temperature effects on water content

Abstract A balance between soil water and air is needed to optimize microbial activity in laboratory incubations. Some fraction of holding capacity (WHC) often used during controlled incubations, yet this level may differ among soils. This study was undertaken develop relationships gravimetric volumetric content, WHC, water‐filled pore space (WFPS) a variety soils, representing eight orders, 46 subgroups, total N from 0.46 4.68 g kg –1 , clay concentration .072 .491 (5–95% range). Gravimetric content determined for each sample under the following sequence conditions: (a) dry storage, (b) when dried at 55 °C, (c) near saturation, (d) drained WHC. calculated 50% WFPS (.50 m 3 –3 ). Like that WFPS, WHC varied strongly with concentrations. To achieve 69 ± 10% 58 3% saturation. Although drying only °C routine processing led overestimation bulk density by 0.012 0.006 Mg it bias. Soil calculations are important obtaining best estimates soil‐test biological other C fractions assess health, research demonstrated using temperature practical but created small consistent