Effects of Agricultural Management on Water Retention via Changes in Organic Carbon in Topsoil and Subsoil

authored by

Laura E. Skadell, Ullrich Dettmann, Georg Guggenberger, Axel Don

Abstract

Background: Increases in soil organic carbon (SOC) through agricultural management can alter soil water retention. This is determined via changes in pore size distribution, namely, air capacity (AC), plant-available water capacity (PAWC), and hygroscopic water capacity (HWC). However, it is uncertain how much soil water retention in topsoil and subsoil can be increased with agricultural management practices. Aims: The aim of this study was to quantify the influence of different agricultural management practices commonly used in Central Europe on AC, PAWC, and HWC in topsoil and subsoil as a result of SOC changes in different soil types. Methods: We sampled topsoil and subsoil at 11 sites across Germany that showed a management-induced SOC increase and a wide range of soil texture and measured the volumetric water content at different pressure heads from saturation to permanent wilting point. Results: In topsoil, AC increased on average by 1.3 mm 100 mm⁻¹ (+17%), PAWC by 1.6 mm 100 mm⁻¹ (+8%), and HWC by 1.6 mm 100 mm⁻¹ (+15%) per 10 g kg⁻¹ increase in SOC. In subsoil, SOC was increased by incorporating compost or topsoil material, which increased AC by 10.0 mm 100 mm⁻¹ (+134%), PAWC by 0.7 mm 100 mm⁻¹ (+3%), and HWC by 0.5 mm 100 mm⁻¹ (+7%) per 10 g kg⁻¹ increase in SOC. The total average increase in PAWC was 1 mm in topsoil and 1 mm in subsoil, with SOC increases by 4 and 5 g kg⁻¹, respectively. Conclusions: More than 50 years of additional farmyard manure addition resulted in an average SOC increase of 3.4 g kg⁻¹, but PAWC increased only slightly by 2.5%, showing the limited impact of agricultural management on water retention capacities.

Organisation(s)

Institute of Earth System Sciences

External Organisation(s)

Johann Heinrich von Thünen Institute, Federal Research Institute for Rural Areas, Forestry and Fisheries

Type

Article

Journal

Journal of Plant Nutrition and Soil Science

Volume

188

Pages

949-963

No. of pages

15

ISSN

1436-8730

Publication date

12.2025

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Soil Science, Plant Science

Sustainable Development Goals

SDG 2 - Zero Hunger, SDG 13 - Climate Action

Electronic version(s)

https://doi.org/10.1002/jpln.70004 (Access: Open)