<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>1405-3195</journal-id>
<journal-title><![CDATA[Agrociencia]]></journal-title>
<abbrev-journal-title><![CDATA[Agrociencia]]></abbrev-journal-title>
<issn>1405-3195</issn>
<publisher>
<publisher-name><![CDATA[Colegio de Postgraduados]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1405-31952006000100027</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Efecto de la estructura del suelo sobre el desarrollo radical del maíz con dos sistemas de labranza]]></article-title>
<article-title xml:lang="en"><![CDATA[Effect of soil structure on corn root development under two tillage systems]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Osuna-Ceja]]></surname>
<given-names><![CDATA[Esteban S.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Figueroa-Sandoval]]></surname>
<given-names><![CDATA[Benjamín]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Oleschko]]></surname>
<given-names><![CDATA[Klaudia]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Flores-Delgadillo]]></surname>
<given-names><![CDATA[María de L.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Martínez-Menes]]></surname>
<given-names><![CDATA[Mario R.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[González-Cossío]]></surname>
<given-names><![CDATA[Félix V.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, INIFAP  ]]></institution>
<addr-line><![CDATA[ Aguascalientes]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Colegio de Postgraduados  ]]></institution>
<addr-line><![CDATA[Montecillo Estado de México]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af3">
<institution><![CDATA[,Universidad Autónoma de México Instituto de Geología Departamento de Edafología]]></institution>
<addr-line><![CDATA[ México, D. F.]]></addr-line>
<country>Mexico</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>02</month>
<year>2006</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>02</month>
<year>2006</year>
</pub-date>
<volume>40</volume>
<numero>1</numero>
<fpage>27</fpage>
<lpage>38</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S1405-31952006000100027&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S1405-31952006000100027&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S1405-31952006000100027&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen La estructura del suelo (arreglo geométrico y topológico de los poros del suelo que se forman entre los agregados, y su estabilidad en tiempo y espacio) es una propiedad básica considerada como uno de los principales atributos de la calidad del suelo. En este estudio se analizaron dos sistemas de labranza de largo plazo bajo riego: tradicional (LT) y de conservación (LC), con especial énfasis en el comportamiento de propiedades como densidad aparente (&#961;b), la pendiente de la curva de retención de humedad en su punto de inflexión (S) y contenido de materia orgánica (MO), así como su relación con el sistema radical del maíz (Zea mays). Se efectuaron pruebas comparativas considerando algunos parámetros de suelo (&#961;b, MO, y S) y planta (biomasa, y longitud de raíz). Los resultados muestran que los parámetros &#961;b, MO y S utilizados para medir la calidad física del suelo, demostraron que los sistemas de labranza causan cambios en la estructura del mismo y por ende en su calidad. El sistema de LC propicia una mejor calidad e incrementa el contenido de MO en el suelo. Los valores de S son menores en LT, lo que indica que tiene menor capacidad de retener agua en comparación con LC. Se encontró una alta correlación entre S y longitud de raíz, significativa al agrupar los datos de acuerdo con el tipo de manejo. Por tanto, S se podría usar como un indicador para evaluar el impacto de las prácticas agrícolas sobre la calidad del suelo.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract The soil structure (the geometric and topological arrangement of the soil pores, which are formed between the aggregates, and its stability over time and space) is a basic property, considered one of the main attributes of soil quality. In this study, two longterm irrigated tillage systems were analyzed: traditional (LT) and conservation (LC) with special emphasis on properties such as bulk density (&#961;b), slope of the water retention curve at its inflection point (S) and content of organic matter (OM), as well as their relationship to the corn root system (Zea mays). Comparative tests were conducted considering soil (&#961;b, OM and S) and plant (biomass and root length) parameters. The results show that the parameters &#961;b, OM and S used to measure physical quality of the soil showed that the tillage systems cause changes in soil structure and, thus, in its quality. The LC system favors better quality and increases the OM content in the soil. The values of S are lower in LT, indicating that it has lower capacity for water retention compared with LC. A high correlation between S and root length was found, significant when data were grouped by type of management. Therefore, S could be used as an indicator to evaluate the impact of agricultural practices on soil quality.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[Zea mays]]></kwd>
<kwd lng="es"><![CDATA[labranza de conservación]]></kwd>
<kwd lng="es"><![CDATA[sistema radical]]></kwd>
<kwd lng="en"><![CDATA[Zea mays]]></kwd>
<kwd lng="en"><![CDATA[conservation tillage]]></kwd>
<kwd lng="en"><![CDATA[root systems]]></kwd>
</kwd-group>
</article-meta>
</front><back>
<ref-list>
<ref id="B1">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ahuja]]></surname>
<given-names><![CDATA[L. R.]]></given-names>
</name>
<name>
<surname><![CDATA[Fiedler]]></surname>
<given-names><![CDATA[F.]]></given-names>
</name>
<name>
<surname><![CDATA[Dunn]]></surname>
<given-names><![CDATA[G. H.]]></given-names>
</name>
<name>
<surname><![CDATA[Benjamin]]></surname>
<given-names><![CDATA[J. G.]]></given-names>
</name>
<name>
<surname><![CDATA[Garrison]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Changes in soil water retention curves due to tillage and natural reconsolidation]]></article-title>
<source><![CDATA[Soil Sci. Soc. Am. J.]]></source>
<year>1998</year>
<volume>62</volume>
<page-range>1228-33</page-range></nlm-citation>
</ref>
<ref id="B2">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Betz]]></surname>
<given-names><![CDATA[C. L.]]></given-names>
</name>
<name>
<surname><![CDATA[Allmaras]]></surname>
<given-names><![CDATA[R. R.]]></given-names>
</name>
<name>
<surname><![CDATA[Copeland]]></surname>
<given-names><![CDATA[S. M.]]></given-names>
</name>
<name>
<surname><![CDATA[Randal]]></surname>
<given-names><![CDATA[G. W.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Least limiting water ranger traffic and long-term tillage influence in a Webster soil]]></article-title>
<source><![CDATA[Soil Sci. Soc. Am. J.]]></source>
<year>1998</year>
<volume>62</volume>
<page-range>1384-93</page-range></nlm-citation>
</ref>
<ref id="B3">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Bruand]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Cousin]]></surname>
<given-names><![CDATA[I.]]></given-names>
</name>
<name>
<surname><![CDATA[Nicoulland]]></surname>
<given-names><![CDATA[B.]]></given-names>
</name>
<name>
<surname><![CDATA[Duval]]></surname>
<given-names><![CDATA[O]]></given-names>
</name>
<name>
<surname><![CDATA[Begon]]></surname>
<given-names><![CDATA[J. C.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Backscattering electron scanning images for analysing soil compaction around roots]]></article-title>
<source><![CDATA[Soil Sci. Soc. Am. J.]]></source>
<year>1996</year>
<volume>60</volume>
<page-range>895-901</page-range></nlm-citation>
</ref>
<ref id="B4">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Brück]]></surname>
<given-names><![CDATA[H.]]></given-names>
</name>
<name>
<surname><![CDATA[Piro]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Sattelmacher]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Payne]]></surname>
<given-names><![CDATA[W. A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Spatial distribution of roots of pearl millet on sandy soils of Niger]]></article-title>
<source><![CDATA[Plant and Soil]]></source>
<year>2003</year>
<volume>256</volume>
<page-range>149-59</page-range></nlm-citation>
</ref>
<ref id="B5">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Bushamuka]]></surname>
<given-names><![CDATA[V. N.]]></given-names>
</name>
<name>
<surname><![CDATA[Zobel]]></surname>
<given-names><![CDATA[R. W.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Differential genotypic and root type penetration of compacted soil layers]]></article-title>
<source><![CDATA[Crop Sci.]]></source>
<year>1998</year>
<volume>38</volume>
<numero>3</numero>
<issue>3</issue>
<page-range>776-81</page-range></nlm-citation>
</ref>
<ref id="B6">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[De Freitas]]></surname>
<given-names><![CDATA[P. L.]]></given-names>
</name>
<name>
<surname><![CDATA[Zobel]]></surname>
<given-names><![CDATA[R. W.]]></given-names>
</name>
<name>
<surname><![CDATA[Snyder]]></surname>
<given-names><![CDATA[V. A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Corn root growth in soil columns with artificially constructed aggregates]]></article-title>
<source><![CDATA[Crop Sci.]]></source>
<year>1999</year>
<volume>39</volume>
<page-range>725-30</page-range></nlm-citation>
</ref>
<ref id="B7">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Dexter]]></surname>
<given-names><![CDATA[A. R.]]></given-names>
</name>
</person-group>
<source><![CDATA[The key to soil function]]></source>
<year>2001</year>
<page-range>14</page-range><publisher-loc><![CDATA[Poland ]]></publisher-loc>
<publisher-name><![CDATA[Institute of Soil Science and Plant Cultivation]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B8">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Dexter]]></surname>
<given-names><![CDATA[A. R.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Soil physical quality. Part I. Theory, effect of soil texture, density, and organic matter, and effect on root growth]]></article-title>
<source><![CDATA[Geoderma]]></source>
<year>2004</year>
</nlm-citation>
</ref>
<ref id="B9">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Dexter]]></surname>
<given-names><![CDATA[A. R.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Soil physical quality. Part II. Friability, tillage, tilth and hard-setting]]></article-title>
<source><![CDATA[Geoderma]]></source>
<year>2004</year>
</nlm-citation>
</ref>
<ref id="B10">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Dexter]]></surname>
<given-names><![CDATA[A. R.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Soil physical quality Part. III. Unsaturated hydraulic conductivity and general conclusion about S-theory]]></article-title>
<source><![CDATA[Geoderma]]></source>
<year>2004</year>
</nlm-citation>
</ref>
<ref id="B11">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Dexter]]></surname>
<given-names><![CDATA[A. R.]]></given-names>
</name>
<name>
<surname><![CDATA[Tanner]]></surname>
<given-names><![CDATA[D. W.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The response of unsaturated soils to isotropic stress]]></article-title>
<source><![CDATA[J. Soil Sci.]]></source>
<year>1973</year>
<volume>24</volume>
<page-range>491-502</page-range></nlm-citation>
</ref>
<ref id="B12">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Dexter]]></surname>
<given-names><![CDATA[A. R.]]></given-names>
</name>
<name>
<surname><![CDATA[Bird]]></surname>
<given-names><![CDATA[N. R. A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Methods for predicting the optimum and the range of soil water contents for tillage based on the water retention curve]]></article-title>
<source><![CDATA[Soil &amp; Till. Res.]]></source>
<year>2001</year>
<volume>57</volume>
<page-range>203-12</page-range></nlm-citation>
</ref>
<ref id="B13">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Eamus]]></surname>
<given-names><![CDATA[D.]]></given-names>
</name>
<name>
<surname><![CDATA[Chen]]></surname>
<given-names><![CDATA[X.]]></given-names>
</name>
<name>
<surname><![CDATA[Kelley]]></surname>
<given-names><![CDATA[G.]]></given-names>
</name>
<name>
<surname><![CDATA[Hutley]]></surname>
<given-names><![CDATA[L.B.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Root biomass and root fractal analyses of an open Eucalyptus forest in savanna of north Australia]]></article-title>
<source><![CDATA[Aust. J. Bot.]]></source>
<year>2002</year>
<volume>50</volume>
<page-range>31-41</page-range></nlm-citation>
</ref>
<ref id="B14">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Follett]]></surname>
<given-names><![CDATA[R. F.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Soil management concepts and carbon sequestration in cropland soils]]></article-title>
<source><![CDATA[Soil &amp; Till. Res.]]></source>
<year>2001</year>
<volume>61</volume>
<page-range>77-92</page-range></nlm-citation>
</ref>
<ref id="B15">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Franzluebbers]]></surname>
<given-names><![CDATA[A. J.]]></given-names>
</name>
<name>
<surname><![CDATA[Langdale]]></surname>
<given-names><![CDATA[G. W.]]></given-names>
</name>
<name>
<surname><![CDATA[Schomgerg]]></surname>
<given-names><![CDATA[H. H.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Soil carbon, nitrogen and aggregation in response to type and frequency of tillage]]></article-title>
<source><![CDATA[Soil Sci. Soc. Am. J.]]></source>
<year>1999</year>
<volume>63</volume>
<page-range>349-55</page-range></nlm-citation>
</ref>
<ref id="B16">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Franzluebbers]]></surname>
<given-names><![CDATA[A. J.]]></given-names>
</name>
<name>
<surname><![CDATA[Haney]]></surname>
<given-names><![CDATA[R. L.]]></given-names>
</name>
<name>
<surname><![CDATA[Honeycutt]]></surname>
<given-names><![CDATA[C. W.]]></given-names>
</name>
<name>
<surname><![CDATA[Schomgerg]]></surname>
<given-names><![CDATA[H. H.]]></given-names>
</name>
<name>
<surname><![CDATA[Hons]]></surname>
<given-names><![CDATA[F. M.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Flush of carbon dioxide following rewetting of dried soil relates to active organic pools]]></article-title>
<source><![CDATA[Soil Sci. Soc. Am. J.]]></source>
<year>2000</year>
<volume>64</volume>
<page-range>613-23</page-range></nlm-citation>
</ref>
<ref id="B17">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Gale]]></surname>
<given-names><![CDATA[W. J.]]></given-names>
</name>
<name>
<surname><![CDATA[Cambardella]]></surname>
<given-names><![CDATA[C. A.]]></given-names>
</name>
<name>
<surname><![CDATA[Bailey]]></surname>
<given-names><![CDATA[T. B.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Surface residue-and root-derived carbon in stable and unstable aggregates]]></article-title>
<source><![CDATA[Soil Sci. Soc. Am. J.]]></source>
<year>2000</year>
<volume>64</volume>
<page-range>196-201</page-range></nlm-citation>
</ref>
<ref id="B18">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Gale]]></surname>
<given-names><![CDATA[W. J.]]></given-names>
</name>
<name>
<surname><![CDATA[Cambardella]]></surname>
<given-names><![CDATA[C. A.]]></given-names>
</name>
<name>
<surname><![CDATA[Bailey]]></surname>
<given-names><![CDATA[T. B.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Root-derived carbon and the formation and stabilization of aggregates]]></article-title>
<source><![CDATA[Soil Sci. Soc. Am. J.]]></source>
<year>2000</year>
<volume>64</volume>
<page-range>201-7</page-range></nlm-citation>
</ref>
<ref id="B19">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Groleau-Renaud]]></surname>
<given-names><![CDATA[V.]]></given-names>
</name>
<name>
<surname><![CDATA[Plantureux]]></surname>
<given-names><![CDATA[S.]]></given-names>
</name>
<name>
<surname><![CDATA[Guckert]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Influence of plant morphology on root exudation of maize subjected to mechanical impedance in hydroponic condictions]]></article-title>
<source><![CDATA[Plant Soil]]></source>
<year>1998</year>
<volume>201</volume>
<page-range>231-9</page-range></nlm-citation>
</ref>
<ref id="B20">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Herrick]]></surname>
<given-names><![CDATA[J. E.]]></given-names>
</name>
<name>
<surname><![CDATA[Weltz]]></surname>
<given-names><![CDATA[M. A.]]></given-names>
</name>
<name>
<surname><![CDATA[Reeder]]></surname>
<given-names><![CDATA[J. D.]]></given-names>
</name>
<name>
<surname><![CDATA[Schuman]]></surname>
<given-names><![CDATA[G. E.]]></given-names>
</name>
<name>
<surname><![CDATA[Simanton]]></surname>
<given-names><![CDATA[J. R.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Rangeland soil erosion and soil quality: role of soil resistance, resilience and disturbance regime]]></article-title>
<source><![CDATA[Soil Water Cons. Soc.]]></source>
<year>1999</year>
</nlm-citation>
</ref>
<ref id="B21">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Huang]]></surname>
<given-names><![CDATA[B.]]></given-names>
</name>
<name>
<surname><![CDATA[Duncan]]></surname>
<given-names><![CDATA[R. R.]]></given-names>
</name>
<name>
<surname><![CDATA[Carrow]]></surname>
<given-names><![CDATA[R. N.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Drough-resistance mechanisms of seven warm-season turfgrass under surface soil drying: II Root aspects]]></article-title>
<source><![CDATA[Crop Sci.]]></source>
<year>1997</year>
<volume>37</volume>
<numero>6</numero>
<issue>6</issue>
<page-range>1863-9</page-range></nlm-citation>
</ref>
<ref id="B22">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Janzen]]></surname>
<given-names><![CDATA[H. H.]]></given-names>
</name>
<name>
<surname><![CDATA[Campbell]]></surname>
<given-names><![CDATA[C. A.]]></given-names>
</name>
<name>
<surname><![CDATA[Izaurralde]]></surname>
<given-names><![CDATA[R. C.]]></given-names>
</name>
<name>
<surname><![CDATA[Ellert]]></surname>
<given-names><![CDATA[B. H.]]></given-names>
</name>
<name>
<surname><![CDATA[Juma]]></surname>
<given-names><![CDATA[N.]]></given-names>
</name>
<name>
<surname><![CDATA[McGill]]></surname>
<given-names><![CDATA[W. B.]]></given-names>
</name>
<name>
<surname><![CDATA[Zentner]]></surname>
<given-names><![CDATA[R. P.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Management effects on soil C storage on the Canadian prairies]]></article-title>
<source><![CDATA[Soil &amp; Till. Res.]]></source>
<year>1998</year>
<volume>47</volume>
<page-range>189-203</page-range></nlm-citation>
</ref>
<ref id="B23">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Jury]]></surname>
<given-names><![CDATA[W. A.]]></given-names>
</name>
<name>
<surname><![CDATA[Gardner]]></surname>
<given-names><![CDATA[W. R.]]></given-names>
</name>
<name>
<surname><![CDATA[Gardner]]></surname>
<given-names><![CDATA[W. H.]]></given-names>
</name>
</person-group>
<source><![CDATA[Soil Physics]]></source>
<year>1991</year>
<publisher-loc><![CDATA[New York ]]></publisher-loc>
<publisher-name><![CDATA[John Wiley &amp; Sons]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B24">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Katou]]></surname>
<given-names><![CDATA[H.]]></given-names>
</name>
<name>
<surname><![CDATA[Miyaji]]></surname>
<given-names><![CDATA[K.]]></given-names>
</name>
<name>
<surname><![CDATA[Kubota]]></surname>
<given-names><![CDATA[T.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Susceptibility of undisturbed soils to compression as evaluated from the changes in the soil water characteristic curves]]></article-title>
<source><![CDATA[Soil Sci. Plant Nutr.]]></source>
<year>1987</year>
<volume>33</volume>
<numero>4</numero>
<issue>4</issue>
<page-range>539-54</page-range></nlm-citation>
</ref>
<ref id="B25">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Kay]]></surname>
<given-names><![CDATA[B. D.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Soil structure]]></article-title>
<person-group person-group-type="editor">
<name>
<surname><![CDATA[Sumner]]></surname>
<given-names><![CDATA[M. E.]]></given-names>
</name>
</person-group>
<source><![CDATA[Handbook of Soil Science]]></source>
<year>1999</year>
<page-range>229-76</page-range><publisher-loc><![CDATA[Boca Raton. FL. USA ]]></publisher-loc>
<publisher-name><![CDATA[CRC Press Inc.]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B26">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Mualem]]></surname>
<given-names><![CDATA[Y.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[A new model for predicting the hydraulic conductivity of unsaturated porous media]]></article-title>
<source><![CDATA[Water Resources Res.]]></source>
<year>1976</year>
<volume>12</volume>
<page-range>513-22</page-range></nlm-citation>
</ref>
<ref id="B27">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Osuna]]></surname>
<given-names><![CDATA[C. E. S.]]></given-names>
</name>
<name>
<surname><![CDATA[Ramírez]]></surname>
<given-names><![CDATA[S. P.]]></given-names>
</name>
<name>
<surname><![CDATA[Villagrana]]></surname>
<given-names><![CDATA[F. E.]]></given-names>
</name>
</person-group>
<source><![CDATA[Desarrollo de sistemas de producción sostenible para uso y conservación de suelo y agua en las zonas áridas y semiáridas del Norte-Centro de México]]></source>
<year>2000</year>
<publisher-name><![CDATA[CONACYT]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B28">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Six]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
<name>
<surname><![CDATA[Elliott]]></surname>
<given-names><![CDATA[E. T.]]></given-names>
</name>
<name>
<surname><![CDATA[Paustian]]></surname>
<given-names><![CDATA[K.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Soil structure and soil organic matter: II. A normalized stability index and the effect of mineralogy]]></article-title>
<source><![CDATA[Soil Sci. Soc. Am. J.]]></source>
<year>2000</year>
<volume>64</volume>
<page-range>1042-9</page-range></nlm-citation>
</ref>
<ref id="B29">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Tsutsumi]]></surname>
<given-names><![CDATA[D.]]></given-names>
</name>
<name>
<surname><![CDATA[Kosugi]]></surname>
<given-names><![CDATA[K.]]></given-names>
</name>
<name>
<surname><![CDATA[Mizuyama]]></surname>
<given-names><![CDATA[T.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Root-system development and water-extraction model considering hydrotropism]]></article-title>
<source><![CDATA[Soil Sci. Soc. Am. J.]]></source>
<year>2003</year>
<volume>67</volume>
<page-range>387-401</page-range></nlm-citation>
</ref>
<ref id="B30">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Tubeileh]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Groleau-Renaud]]></surname>
<given-names><![CDATA[V.]]></given-names>
</name>
<name>
<surname><![CDATA[Plantureux]]></surname>
<given-names><![CDATA[S.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Effect of soil compaction on photosynthesis and carbon pertitioning within a maize-soil system]]></article-title>
<source><![CDATA[Soil &amp; Till. Res.]]></source>
<year>2003</year>
<volume>71</volume>
<page-range>151-61</page-range></nlm-citation>
</ref>
<ref id="B31">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Van Genuchten]]></surname>
<given-names><![CDATA[M. Th.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[A closed-form equation for predicting the hydraulic conductivity of unsaturated soils]]></article-title>
<source><![CDATA[Soil Sci. Soc. Am. J.]]></source>
<year>1980</year>
<volume>44</volume>
<page-range>892-8</page-range></nlm-citation>
</ref>
<ref id="B32">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Van Genuchten]]></surname>
<given-names><![CDATA[M. Th.]]></given-names>
</name>
<name>
<surname><![CDATA[Leij]]></surname>
<given-names><![CDATA[F. J.]]></given-names>
</name>
<name>
<surname><![CDATA[Yates]]></surname>
<given-names><![CDATA[S. R.]]></given-names>
</name>
</person-group>
<source><![CDATA[The RETC code for quantifying the hydraulic functions of unsaturated soils]]></source>
<year>1991</year>
<publisher-name><![CDATA[USDA, US Salinity Laboratory, Riverside, C.A. US Environmental Protection Agency]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B33">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Vaz]]></surname>
<given-names><![CDATA[C. M. P.]]></given-names>
</name>
<name>
<surname><![CDATA[Bassoi]]></surname>
<given-names><![CDATA[L. H.]]></given-names>
</name>
<name>
<surname><![CDATA[Hopmans]]></surname>
<given-names><![CDATA[J. W.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Contribution of water content and bulk density to field soil penetration resistance as measured by a combined cone penetrometer-TDR probe]]></article-title>
<source><![CDATA[Soil &amp; Till. Res.]]></source>
<year>2001</year>
<volume>60</volume>
<page-range>35-42</page-range></nlm-citation>
</ref>
<ref id="B34">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Vogel]]></surname>
<given-names><![CDATA[H. J.]]></given-names>
</name>
<name>
<surname><![CDATA[Roth]]></surname>
<given-names><![CDATA[K.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Quantitative morphology and network representation of soil pore structure]]></article-title>
<source><![CDATA[Adv. Water Resour.]]></source>
<year>2001</year>
<volume>24</volume>
<page-range>233-42</page-range></nlm-citation>
</ref>
<ref id="B35">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Vrugt]]></surname>
<given-names><![CDATA[J. A.]]></given-names>
</name>
<name>
<surname><![CDATA[Hopmans]]></surname>
<given-names><![CDATA[J. W.]]></given-names>
</name>
<name>
<surname><![CDATA[&#352;imunek]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Calibration of a two-dimensional root water uptake model]]></article-title>
<source><![CDATA[Soil Sci. Soc. Am. J.]]></source>
<year>2001</year>
<volume>65</volume>
<page-range>1027-37</page-range></nlm-citation>
</ref>
<ref id="B36">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Walkley]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Black]]></surname>
<given-names><![CDATA[T. A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[An examination of the Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid titration method]]></article-title>
<source><![CDATA[Soil Sci.]]></source>
<year>1934</year>
<volume>63</volume>
<page-range>251-64</page-range></nlm-citation>
</ref>
<ref id="B37">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Williams]]></surname>
<given-names><![CDATA[S. M.]]></given-names>
</name>
<name>
<surname><![CDATA[Weil]]></surname>
<given-names><![CDATA[R. R.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Crop cover root channels may alleviate soil compaction effects on soybean crop.]]></article-title>
<source><![CDATA[Soil Sci. Soc. Am. J.]]></source>
<year>2004</year>
<volume>68</volume>
<page-range>1403-9</page-range></nlm-citation>
</ref>
<ref id="B38">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Zobel]]></surname>
<given-names><![CDATA[R. W.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Root growth and development]]></article-title>
<person-group person-group-type="editor">
<name>
<surname><![CDATA[Keister]]></surname>
</name>
<name>
<surname><![CDATA[Cregan]]></surname>
</name>
</person-group>
<source><![CDATA[The Rhizosphere and Plant Growth]]></source>
<year>1991</year>
<page-range>61-71</page-range><publisher-loc><![CDATA[Dordrecht, the Netherlands ]]></publisher-loc>
<publisher-name><![CDATA[Kluwer Academic Publ.]]></publisher-name>
</nlm-citation>
</ref>
</ref-list>
</back>
</article>
