Factors contributing to temporal stability in spatial patterns of water content in the tillage zone

Silva, Álvaro Pires da; Nadler, Arie; Kay, B. D.

doi:10.1016/s0167-1987(00)00169-0

Cited by 87 publications

(50 citation statements)

References 11 publications

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“…Seasonal average water contents at 0-15 cm depth ranged from 42 to 51% WFPS in 1998, but from 69 to 81% WFPS in 2000 (Table 3). Although spatial patterns in soil water content are generally temporally stable (da Silva et al 2001), this generalization would not apply when the spatial patterns in water contents in very wet periods are compared with those in very dry periods. Such was the case in 1998 and 2000.…”

Section: Water Content and Depthmentioning

confidence: 99%

Factors influencing mineralizable carbon in a landscape with variable topography

Chan¹,

Gregorich²

2007

Can. J. Soil. Sci.

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. 2007. Factors influencing mineralizable carbon in a landscape with variable topography. Can. J. Soil Sci. 87: 495-509. Management-induced erosion has substantially increased the spatial variability in soil organic carbon (OC) stocks in landscapes with variable topography, but its impact on C dynamics is not well understood. The variability in cumulative C mineralization of samples from five positions in a landscape was examined in an incubation study and the effects of water content and depth within the A horizon were assessed. Mineralization was generally at a maximum at water contents between 80 and 95% water-filled pore space. The amount of C mineralized increased with OC content, but the proportion of the mineralizable OC decreased with increasing OC content. Few significant differences in C mineralization existed between surface and subsurface layers of the A horizon. The spatial patterns in maximum C mineralization were generally indicative of the patterns obtained when mineralization was calculated using spatial patterns of actual seasonal average water contents. This suggests the spatial pattern of maximum mineralization was not strongly influenced by variable hydrologic conditions on this site and reflects the spatial patterns in annual mineralization. The proportion of OC mineralized was not related to the proportion of the OC in particulate organic carbon (POC) or in the silt + clay fractions, but was significantly negatively related to the saturation of the clay + silt fraction with C. We speculate that the decline in the proportion of mineralized OC with increasing OC content reflects an increased proportion of the capacity of the silt + clay fraction to retain and physically protect OC within microaggregates.Key words: Erosion, deposition, mineralizable organic carbon, spatial variability Chan, C., Kay, B. D. et Gregorich, E. G. 2007. Facteurs influençant la minéralisation du carbone dans un paysage à relief variable. Can. J. Soil Sci. 87: 495-509. L'érosion qui résulte de la gestion des terres a sensiblement accru la variabilité spatiale des réserves de carbone organique (CO) du sol dans les paysages à relief variable, mais on comprend mal son incidence sur la dynamique du carbone. Les auteurs ont vérifié la variabilité de la minéralisation cumulative du C dans les échantillons prélevés à cinq endroits, dans un paysage, lors d'une étude d'incubation puis ont évalué les effets de la teneur en eau et de la profondeur dans l'horizon A examiné. En général, la minéralisation atteint un maximum quand la teneur en eau correspond à 80-95 % de l'espace occupé par les pores emplis d'eau. La quantité de C minéralisé s'accroît avec la concentration de CO, mais la proportion de CO minéralisable diminue à mesure qu'augmente la concentration de CO. La minéralisation du C varie peu entre la couche superficielle et les couches inférieures de l'horizon A. Dans l'ensemble, la minéralisation maximale du C suit une tendance spatiale analogue à celle observée quand on calcule la minéralisation à partir des tendances ...

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Section: Water Content and Depthmentioning

confidence: 99%

Factors influencing mineralizable carbon in a landscape with variable topography

Chan¹,

Gregorich²

2007

Can. J. Soil. Sci.

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“…As a consequence, many studies have investigated alternative approaches by attempting to find representative locations using other properties that can affect SWC, but the identification of representative locations remains inconsistent. For example, da Silva et al (2001) observed that organic-carbon and clay contents could serve as better explanatory variables than topographic variables. In contrast, Gómez-Plaza et al (2000) found that vegetation and topography rather than soil properties were more likely to be the primary factors affecting the temporal stability of SWC.…”

Section: Introductionmentioning

confidence: 99%

Profile distribution of soil–water content and its temporal stability along a 1340-m long transect on the Loess Plateau, China

Shao

Jia

et al. 2016

CATENA

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Information on the profile characteristics of soil-water content (SWC) and its temporal stability is essential for an accurate understanding of hydrological processes. This study investigated changes of spatial variation and temporal stability of SWC in soil profiles and estimated mean SWC based on direct and indirect methods. SWCs were measured at 20-cm intervals in the soil profiles to a depth of 3 m using neutron probes at 135 locations along a 1340-m long transect on 18 sampling dates from 2012 to 2013 on the Loess Plateau in China. The coefficient of variation over space (CV S ) of SWC first decreased and then increased vertically. The coefficient of variation over time (CV T ) of SWC decreased along the soil profiles. The spatial patterns of SWC strongly persisted vertically and temporally. Mean Spearman's rank correlation coefficients decreased from a depth of 10 to a depth of 20 cm, fluctuated from 20 to 180 cm, and then increased below 200 cm. Temporal stability increased along the soil profiles based on the standard deviation of mean relative difference (SDRD) and the mean absolute bias error (MABE). The number of locations with an SDRD and/or MABE b 5% increased along the soil profile, and the number of locations with a mean relative difference within ±5% and/or representative locations were variably dependent on depth. Both direct and indirect methods could accurately estimate the mean SWC for each depth based on the mean absolute relative errors and root mean square errors. The driest and wettest locations tended to remain representative for more depths than did locations with mean-moistures. The driest locations were more likely to be the most temporally stable. These findings should improve our understanding of soil-water dynamics in soil profiles.

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“…grasslands (Vachaud et al 1985;Schneider et al 2008;Brocca et al 2009;Zhao et al 2010), croplands (da Silva et al 2001;Cosh et al 2004;Jacobs et al 2004;Heathman et al 2012), forests (Lin 2006), gullies (Gao et al 2013), and mountains (Grant et al 2004;Guber et al 2008;Vivoni et al 2008;Williams et al 2009). Temporally unstable spatial patterns, however, were reported in a cultivated Vesuvian soil (Comegna and Basile 1994).…”

Section: Introductionmentioning

confidence: 99%

“…Currently, soil texture has been commonly implicated in the existence and extent of temporal stability of soil moisture (Vachaud et al 1985;da Silva et al 2001;Hu et al 2010a;Biswas and Si 2011;Jia et al 2013a). Jacobs et al (2004) found that the most temporally stable locations were associated with moderate to moderately high clay contents, but Mohanty and Skaggs (2001) found that sandy loam fields had a more pronounced temporal stability than did silty loam fields.…”

Section: Introductionmentioning

confidence: 99%

Temporal stability of soil moisture on two transects in a desert area of northwestern China

2016

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Temporal stability of soil moisture has important implications for optimal and effective field monitoring and has been observed for a range of soil and landscape conditions. However, relatively less is known about temporal stability of soil moisture in desert areas. In this study, two 5-km transects (TranA and TranB) with different soil properties in a desert area of northwestern China were chosen to assess the characteristics of the temporal variability and stability of soil moisture, to identify representative sampling locations (RSLs), and to evaluate the effect of sampling frequency on the determination of temporal stability. For each transect, moisture contents of the surface soil were measured using Theta Probes on 35 occasions at 51 locations from April to October 2012. The results showed that soil moisture for the finer-textured TranA was consistently higher and more variable than for the coarsertextured TranB. Both transects exhibited strong temporal stability during the monitoring period. Locations with higher sand contents tended to have more pronounced temporal stabilities. The RSL identified in each transect accurately represented the mean moisture contents of the transects over time, with coefficients of determination (R 2 )higher than 0.95 and root mean square errors lower than 1 % vol/vol. Soil moisture has significantly higher degrees of temporal stability during dry periods than during wet periods. The effect of sampling frequency on temporal stability of soil moisture was not as evident, particularly for the coarser-textured soil. This study provides insights for designing strategies for the sampling and monitoring of soil moisture in the hydrological applications in desert areas.

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Factors contributing to temporal stability in spatial patterns of water content in the tillage zone

Cited by 87 publications

References 11 publications

Factors influencing mineralizable carbon in a landscape with variable topography

Factors influencing mineralizable carbon in a landscape with variable topography

Profile distribution of soil–water content and its temporal stability along a 1340-m long transect on the Loess Plateau, China

Temporal stability of soil moisture on two transects in a desert area of northwestern China

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