کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4479281 1316434 2011 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Time-variable soil hydraulic properties in near-surface soil water simulations for different tillage methods
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم زراعت و اصلاح نباتات
پیش نمایش صفحه اول مقاله
Time-variable soil hydraulic properties in near-surface soil water simulations for different tillage methods
چکیده انگلیسی

Simulating near-surface soil water dynamics is challenging since this soil compartment is temporally highly dynamic as response to climate and crop growth. For accurate simulations the soil hydraulic properties have to be properly known. Although there is evidence that these properties are subject to temporal changes, they are set constant over time in most simulations studies. The objective of this study was to improve near-surface soil water simulations by accounting for time-variable hydraulic properties. Repeated tension infiltrometer measurements over two consecutive seasons were used to inversely estimate the hydraulic properties of a silt loam soil under different tillage – conventional (CT), reduced (RT), and no-tillage (NT). Simulated water dynamics with constant and time-variable hydraulic parameters were compared to observed data in terms of the soil water content and water storage in the near-surface soil profile (0–30 cm). The measurements indicate a considerable temporal variability in the saturated hydraulic conductivity, the field-saturated water content and the parameter α of the van Genuchten/Mualem model. Temporal variability was largest for CT and RT, whereas under NT, replicates of measured water contents and hydraulic properties showed a considerable large spatial variability. Simulations with time-constant hydraulic parameters led to underestimations of soil water dynamics in winter and early spring and overestimations during late spring and summer. The use of time-variable hydraulic parameters significantly improved simulation performance for all treatments, resulting in average relative errors below 13%. Since simulation results agreed with observed water dynamics in two seasons, the applicability of inversely estimated hydraulic properties for soil water simulations is demonstrated. Thus, simulations that address applied questions in agricultural water management may be improved by using time-variable hydraulic parameters. The simulated water balance indicated that RT and NT result in better water storage than CT and therefore may increase water efficiency under water-limited climatic conditions.


► Tension infiltrometry gives reliable hydraulic parameters for soil water simulations.
► Time-variable hydraulic properties improve near-surface soil water simulations.
► Reduced and no-tillage improve water storage under dry climatic conditions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Agricultural Water Management - Volume 99, Issue 1, November 2011, Pages 42–50
نویسندگان
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