Variability of in situ soil water retention curves under different tillage systems and growing seasons

Urša Pečan (Author), Marina Pintar (Author), Rok Mihelič (Author), Damijana Kastelec (Author)

Abstract

However, a soil water retention curve (SWRC) is usually considered to be static and is determinedin a laboratory on a limited number of small soil samples. Field SWRCs were determined at a depth of 20 cm on Mollic Gleysol. Measurements were made in two growing seasons at different spatial locations on plots with different tillage systems: no-tillage (NT) and conventional tillage (CT). The unimodal van Genuchten retention function (VG) was fitted to each SWRC and model parameters were estimated. We evaluated the variability of the curves within growing seasons, predicted soilwater contents at field capacity, and evaluated the differences in the estimated parameters of the VG model between different growing seasons and tillage systems considering intraseasonal and spatial variability. The shape of the curves depended more on the environmental conditions during the growing season than on the tillage system. In the wetter and cooler growing season of 2020, when soybeans were grown, the soil retained water in a narrower range. In the drier growing season of 2021, when maize was grown, intraseasonal variability in SWRCs was greater than in 2020. Regardless of the growing season, estimated α values were more intraseasonally variable under the CT than under the NT. Based on the SWRCs, predicted water contents at field capacity varied intraseasonally, seasonally, and spatially. Accounting for spatial and intraseasonal variability, the estimated VG parameter θr differed between years, regardless of tillage system. In 2020, the parameter α was higher under the NT system than under the CT system. Under the CT, α differed between years, while under NT it did not. For the parameter n, there were no significant differences between tillage systems or growing seasons. Seasonal, intraseasonal, and spatial variability in soil hydraulic properties should be considered in soil water modelling studies.

Keywords

Soil water retention curve;tillage systems;spatial variability;temporal variability;Van Genuchten model parameters;

Data

Language:	English
Year of publishing:	2023
Typology:	1.01 - Original Scientific Article
Organization:	UL BF - Biotechnical Faculty
UDC:	631.4
COBISS:	162621443
ISSN:	1879-3444
Views:	88
Downloads:	12
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary keywords:	fizikalne lastnosti tal;zadrževanje vode v tleh;sistemi za obdelavo tal;obdelava tal;prostorska variabilnost;časovna variabilnost;model Van Genuchten;
Type (COBISS):	Article
Pages:	11 str.
Volume:	ǂVol. ǂ233
Issue:	ǂart. no.ǂ 105779
Chronology:	2023
DOI:	10.1016/j.still.2023.105779
ID:	19862010