Ion Diffusion in the Soil–Root System

Jungk, A.; Claassen, N.

doi:10.1016/s0065-2113(08)60662-8

Cited by 186 publications

(142 citation statements)

References 147 publications

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“…Typical values of the volume fraction of liquid in soils φ l and impedance factor f suitable for crop growth are in the range 0.1 to 0.5 [67] Péclet number terms can also almost always be neglected compared to the terms containing λ, since λ depends linearly on root radius a. In order to have aV /Dφ l = P e < λ = F m a/(DK m φ l ) we need to have V < F m /K m .…”

Section: Parameter Estimationmentioning

confidence: 99%

A mathematical model of plant nutrient uptake

Koebernick¹,

Fowler²,

Darrah

2001

Journal of Mathematical Biology

113

159

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This thesis deals with the mathematical modelling of nutrient uptake by plant roots. It starts with the Nye-Tinker-Barber model for nutrient uptake by a single bare cylindrical root. The model is treated using matched asymptotic expansion and an analytic formula for the rate of nutrient uptake is derived for the first time. The basic model is then extended to include root hairs and mycorrhizae, which have been found experimentally to be very important for the uptake of immobile nutrients. Again, analytic expressions for nutrient uptake are derived. The simplicity and clarity of the analytical formulae for the solution of the single root models allows the extension of these models to more realistic branched roots. These models clearly show that the "volume averaging of branching structure" technique commonly used to extend the Nye-Tinker-Barber with experiments can lead to large errors. The same models also indicate that in the absence of large-scale water movement, due to rainfall, fertiliser fails to penetrate into the soil. This motivates us to build a model for water movement and uptake by branched root structures. This model considers the simultaneous flow of water in the soil, uptake by the roots, and flow within the root branching network to the stems of the plant. The water uptake model shows that the water saturation can develop pseudo-steadystate wet and dry zones in the rooting region of the soil. The dry zone is shown to stop the movement of nutrient from the top of the soil to the groundwater. Finally we present a model for the simultaneous movement and uptake of both nutrients and water. This is discussed as a new tool for interpreting available experimental results and designing future experiments. The parallels between evolution and mathematical optimisation are also discussed.

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Section: Parameter Estimationmentioning

confidence: 99%

A mathematical model of plant nutrient uptake

Koebernick¹,

Fowler²,

Darrah

2001

Journal of Mathematical Biology

113

159

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“…found that in-situ resin bag P concentrations peaked during the cool winter period in the Chihuahuan desert and that laboratory extractions done at 4 o C recover significantly more P than those done at 25 o C (Magid and Nielsen 1992). Although diffusion rates of solution-phase ions decrease with decreasing temperature, effective P diffusion in calcareous soils may actually increase with decreasing temperatures above freezing because H 2 CO 3 generation facilitates carbonate dissolution and the transition of solid-phase P to solution-phase P (Jungk and Claassen 1997). Bromus growth rates were greatest in winter, and were positively correlated with K and P/Ca and inversely with ANP.…”

Section: Discussionmentioning

confidence: 97%

Exotic Annual Grasses in Western Rangelands: Predicting Resistance and Resilience of Native Ecosystems to Invasion (Draft)

Belnap¹,

Evans²,

Phillips³

et al. 2004

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Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. REPORT DATE APR 20042. REPORT TYPE CS 11445e. TASK NUMBER 5f. WORK UNIT NUMBER PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) USGS/Canyonlands Field Station 2290 South West Resource Boulevard Moab, UT 845328. PERFORMING ORGANIZATION REPORT NUMBER SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)Strategic SERDP SPONSOR/MONITOR'S REPORT NUMBER(S) DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release, distribution unlimited SUPPLEMENTARY NOTESThe original document contains color images. ABSTRACTBromus tectorum (hereafter referred to as Bromus) is a non-native annual grass from the Mediterranean region that arrived in the United States in the late 19th century and soon spread throughout the western states. Bromus now dominates millions of hectares of low and midelevation landscapes. Where this occurs, native plant and animal diversity is reduced and sometimes extirpated, fire frequencies are increased, community productivity is decreased, and soil biota and nutrient cycles are altered. This has led to a many research efforts to understand the impact of Bromus on native ecosystems and to identify ways to prevent invasion and/or to restore invaded landscapes. We would also like to gratefully acknowledge the SERDP program that provided the funding for this prodigious effort and the ever-cheerful SERDP staff, including Brenda Batch, Matie Desjardin, Jeffrey Marqusee, Veronica Rice, and Brad Smith. We would especially like to thank Bob Holst, who was always immensely helpful and supportive, and Susan Walsh who saved us from innumerable web-based calamities. 1 Executive SummaryBromus tectorum (hereafter referred to as Bromus) is a non-native annual grass from the Mediterranean region that arrived in the United States in the late 19 th century and soon spread throughout the western states. Bromus now dominates millions of hectares of low and midelevation landscapes. Where this occurs, native plant and animal diversity is reduced and sometimes extirpated, fire frequencies are increased, community productivity is decreased, and soil biota and nutrient cycles are altered. This has led to a many research efforts to understand the impact of Bromus on native ecosystems and to identify ways to prevent inva...

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“…Also, at this stage there was a weak negative correlation between soil available phosphorus and organic matter content. P ions can be transferred from the solid phase of the sol due to a concentration gradient (Jungk et Claassen, 1997), for example, the amounts of diffusible P in 1 week vary between 1 and 39 mg/g in the 0-15 cm horizon.…”

Section: Discussionmentioning

confidence: 99%

Combined Effect of Three Pesticides (Zoom, Topik and Ortiva) and Phosphorus Fertilization on Some Physicochemical Parameters of Soil

Ketif¹,

Djamaï²,

Abdennour³

et al. 2014

JAS

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The purpose of this study was to verify the effect of three pesticides (Zoom, Topik and Ortiva) on some physicochemical parameters of soil. To do this, phosphate fertilizer was applied before planting and pesticides were sprayed pre-and post-emergence of Durum wheat. Particle size analysis showed that the soil was characterized by a clay texture and the value of residual humidity does not exceed 8%. The study of pH showed a remarkable seasonal variability; it was in the vicinity of neutrality at the beginning of culture (7.22) to the vicinity of acidity after crop harvest (5.78), thus the change in pH water was due to the phenomenon of dilution. The electrical conductivity proved that the soil was not saline. The content of soil organic matter was experiencing significant seasonal variation. After applying different doses of phosphate fertilizers, soil phosphorus varied remarkably with the seasons, which can be affected by adsorption, precipitation, heading stage, and the presence of clay cation Fe, Al and Ca. It was also noticed an increase in the content of soil available phosphorus during the tillering stage, which is due to the phenomenon of desorption and dissolution. The existence of traces of pesticides indicates that the Topik molecules are more resistant to degradation.

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Ion Diffusion in the Soil–Root System

Cited by 186 publications

References 147 publications

A mathematical model of plant nutrient uptake

A mathematical model of plant nutrient uptake

Exotic Annual Grasses in Western Rangelands: Predicting Resistance and Resilience of Native Ecosystems to Invasion (Draft)

Combined Effect of Three Pesticides (Zoom, Topik and Ortiva) and Phosphorus Fertilization on Some Physicochemical Parameters of Soil

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