In der vorliegenden Arbeit wurde die Methode der magnetischen Kernspinresonanz (NMR) eingesetzt, um beim Schadstoffabbau stattfindende Prozesse und geochemische Reaktionen zerstörungs- und beprobungsfrei zu untersuchen. Dies ist möglich, da die gelösten Elektronenakzeptoren Sauerstoff und Eisen paramagnetisch sind und somit einen Ein uss auf die NMRRelaxationszeiten ausüben. Der lineare Zusammenhang zwischen der gelösten Sauerstoff- beziehungsweise Eisen-Konzentration und den NMR-Relaxationsraten 1/T1 und 1/T2 wurde quantifiziert. Weiterhin wurde der bereits bekannte Einfluss der Matrixoberflächen von porösen Medien auf die Relaxation von Wasser nachgewiesen. Die paramagnetischen Zentren auf Sandoberflächen führen ebenfalls zu einer Verkürzung der Relaxationszeiten. Es wurde gezeigt, dass die kleinsten Korngrößen der verwendeten Sande den größten Einfluss auf die Oberflächenrelaxation haben. Wird die Oberflächenrelaxation berücksichtigt, ist auch in porösen Medien die ermittelte lineare Abhängigkeit der Relaxationszeiten von der Ionenkonzentration anwendbar, um den Gehalt an gelösten paramagnetischen Ionen aus Relaxationsmessungen zu ermitteln. Beispielhaft wurde der Anstieg der Eisen(III)-Konzentration in der Porenlösung von natürlichen Sanden infolge der Auflösung eisenhaltiger Mineralien von den Oberflächen zeitlich und räumlich detailliert betrachtet. Eine durchgeführte Modellierung zeigte, dass das Reaktionssystem zu Beginn der Reaktion von der Diffusion dominiert wird, am Ende dann die Reaktionsgeschwindigkeit der bestimmende Parameter ist. Die beim biologischen Schadstoffabbau auftretenden Redoxprozesse des Eisens wurden durch rein chemische Reaktionen unter Verwendung von Oxidations- und Reduktionsmitteln simuliert. Die zeitlich und räumlich detaillierte Beobachtung des Anstiegs beziehungsweise des Abfalls der gelösten Eisen(III)-Konzentration in der (Poren-)Lösung war mit NMR-Relaxometrie trotz der Schnelligkeit der Reaktionen möglich. Mit Hilfe der anschliessenden Modellierung wurde der wichtige Einfluss des pH-Wertes auf den genauen Ablauf der Reaktionen deutlich gemacht. Nur in sehr sauren pH-Bereichen (pH < 3) liegen die Eisen(III)-Ionen in Lösung vor. Weiterhin wurde der Einfluss der Mikroorganismen selbst auf die NMR-Relaxations- und Diffusionsmessungen untersucht. Im Rahmen dieser Arbeit wurde an Medien mit Lactobacillus und Penicillium eine Verschiebungen in den Relaxationszeitverteilungen hin zu kleineren Relaxationszeiten gemessen. Dies basiert auf der bereits bekannten Verringerung der Mobilität der Spins innerhalb der Biomasse. Für Bakterien von Geobacter metallireducens konnte erstmals der Verbrauch von Eisen(III)-Ionen durch Reduktion während des Wachstum anhand der ansteigenden T2-Relaxationszeit gezeigt werden.

Archaeological artefacts excavated today are in a worse preserved state compare to those artefacts found before 1945. Previous research highlighted soil acidification as the main cause. However, not much research has been done to analyse other causalities, such as the spread of road salt during the wintertime and the potential deterioration that salt (sodium chloride) might cause on the physical cultural heritage. Nonetheless, it is proven that salt causes corrosion on infrastructure and on porous stone, masonry, and other composite materials in buildings. The aim of this work is to investigate how road salt move from the road surface (municipal– and state roads) and beyond, what factors might contribute to increased geographical spread and how we can limit the potential risk of damage associated with the spread of road salts to ancient historical sites. The research methods presented in this paper is a mix of field sampling study together with GIS– and literature analysis. The results show that the road salts spread according to an exponential decaying rate, where most of the road salts being spread 5–10 meters beyond the roadside. This means that cultural heritage sites within this buffer–area could be susceptible to salt induced damage to physical structures and deposited artefacts made from metals, rock, brick, and other material. Thereby it is pivotal to highlight the possible actions that can prevent the spread of road salts in a geographical landscape, and its effect on the physical cultural heritage.

Maize is the dominant crop in northwestern Germany and is mostly cultivated on sandy soils. Additionally, due to intensive livestock husbandry and biogas production, large amounts of liquid manures are produced. The current farm practice leads to high N and P surpluses at field level accompanied by environmental pollution, like nitrate leaching, eutrophication of non-agricultural ecosystems, and N2O emissions. The accruing liquid manures are often used for maize fertilization. Thereby, slurries are mainly broadcast applied using trailing hose applicators followed by incorporation into the topsoil. In addition, a mineral N P starter fertilizer (MSF) is band-applied below the seed-corn at planting to overcome the limited nutrient availability during the early growth stages. Using a slurry injection technique below the maize row before planting might serve a substitute for MSF. Addition of a nitrification inhibitor (NI) into the slurry before injection seems to be an option to further decrease N losses. The objectives of this thesis were to compare the current and novel fertilizing strategies with a special focus on soil mineral nitrogen (SMN) dynamics and plant P, zinc (Zn) and manganese (Mn) status. For both issues the effect of adding a NI into the slurry was investigated. To characterize the SMN dynamics after slurry injection an appropriate soil sampling strategy had to be developed. Therefore, three consecutive field trials were conducted. The first testing of the new soil sampling approach was implemented in an existing experiment where the slurry was injected at a depth of 12 cm (upper rim) below the soil surface. The soil profile (75 cm wide) centered below the maize row was sampled using a grid-like approach to a depth of 90 cm. Around the injection zone, soil monoliths (SM) were sampled using a purpose-built soil shovel. Below the SMs and in the interrow space (15 and 30 cm distance to the row) a standardized auger procedure was used. The second experiment aimed to improve the sampling strategy with focus on sample homogenization quality and necessary sample sizes per pooled sample. In the third experiment this improved sampling strategy was validated. Results from the first testing of the sampling procedure showed that the strategy is suitable, although some problems occurred. Especially the high spread in values among the replications caused high coefficients of variation (CV; mostly 40 – 60%). The improvement trial revealed that for the SM, which contains the slurry band, an intensive homogenization is required. In addition, suitable sample sizes (twelve auger samples and six soil monolith samples per pooled sample) have to be collected to obtain reliable SMN values. Following this enhanced sampling strategy in the final validation trial, the spread in values was considerably reduced and resulted in CV values of mostly < 20%. The method can be adapted to other fertilizer placement strategies and further row crops. To compare both fertilizing strategies with respect to the spatial and temporal SMN dynamics as well as to the plant nutrient status two field trials were conducted using pig slurry on sandy soils in 2014 and 2015. Four treatments were tested: unfertilized control, broadcast application + MSF, injection, and injection + NI. Soil samples were taken using the new sampling strategy at several dates during the growing season. Plant samples were simultaneously collected to evaluate the plant P, Zn, and Mn status at different growth stages. In 2014, all fertilized N was displaced from the top soil layer of the broadcast treatment until the 6-leaf stage due to heavy rainfall, while N displacement was significantly smaller after slurry injection. The lateral movement of injected slurry N was negligible. In 2015, almost no displacement of fertilized N out of the top soil layer occurred independently of treatments, due to distinctly lower rainfall. The release of slurry N was delayed following broadcast application and large SMN concentrations were detected in the injection zones until the 10-leaf stage. The addition of a NI resulted in significantly increased NH4-N shares in the injection zone throughout the early growth stages (+ 46% in 2014 and + 12% in 2015 at 6-leaf stage). Thus, in 2014 SMN displacement was delayed, and in 2015 increased SMN concentrations were found around the slurry band, most probably due to lower N losses via denitrification. Furthermore, NI addition significantly increased the nutrient uptake by maize during early growth in both years. With P deficiency due to cold weather conditions in 2015, broadcast application showed higher P uptake until the 6-leaf stage (36 – 58%), while it was lower at the 8- (32%) and 10- (19%) leaf stages compared to slurry injection (+ NI). Zn availability was enhanced during early growth after slurry injection (+ NI) and Zn as well as Mn uptake were higher at harvest. Furthermore, dry matter yields were higher (2014) or equal (2015) compared to broadcast application. The P balances were decreased by 10 – 14 kg P ha-1, while Zn and Mn balances were excessive independent of treatments. The field trials showed that after slurry injection, especially when combined with a NI, the applied nitrogen is located in a soil zone with better spatial availability for plant roots compared to broadcast application. Furthermore, the MSF can be substituted without affecting early growth of maize. In conclusion, slurry injection leads to equal (or even higher) yields and enables farmers in northwestern Germany to reduce the P and N surpluses. This would support several goals concerning sustainable land use: Lower pollution of ground and surface waters, reduced emission of NH3, more efficient use of the limited rock P reserves, and less need of transporting organic manures out of regions with intensive animal husbandry and/or biogas production. However, slurry injection enhances the risk of N2O emissions, which contributes to climate change. Thus, for a final evaluation of the environmental impact a life cycle assessment would be worthwhile.

No description available.

Durch die Flutung stillgelegter Tagebaue entstehen zahlreiche Seen in den ostdeutschen Braunkohlerevieren. Sie sind überwiegend groß, oligo- bis mesotroph, und ihr Litoral ist nur in geringem Umfang durch Makrophyten strukturiert. Viele von ihnen sind versauert oder versauerungsgefährdet. In einer Feldstudie wurden (1) die Auswirkung von Seemorphologie und Habitatstruktur auf die Fischgemeinschaft des Senftenberger Sees, eines 1050 ha großen mesotrophen Tagebausees, und (2) die Säuretoleranz einheimischer Fischarten unter den hydrochemischen Bedingungen der geogen versauerten Tagebauseen untersucht. Die Fischgemeinschaft des Senftenberger Sees wurde von Barschen (Perca fluviatilis) und Plötzen (Rutilus rutilus) dominiert, wobei die verschiedenen Barsch- und Plötzengrößenklassen ihre Habitate durch Nutzung verschiedener Tiefenbereiche des Litorals segregierten. Innerhalb der flachen Litoralbereiche waren juvenile Plötzen und juvenile Güstern deutlich stärker auf die wenigen Makrophytenbestände fixiert als juvenile Barsche. Die Habitatwahl der Barsche zeigt, dass diese in mesotrophen Seen wahrscheinlich eher von den guten Sichtverhältnissen als von der strukturellen Komplexität submerser Makrophytenbestände profitieren. Als Ursache für die unterschiedliche Habitatwahl juveniler Barsche, Plötzen und Güstern wird postuliert, dass diese generell verschiedene Habitatwahlstrategien verfolgen. Während der entscheidende Parameter für die Habitatwahl juveniler Barsche die Optimierung der Energieaufnahme ist, folgen juvenile Plötzen und Güstern vorrangig einer Räubervermeidungsstrategie und sind daher sehr viel stärker auf strukturreiche Bereiche angewiesen. Die kritischen pH-Untergrenzen für die einzelnen Fischarten entsprachen weitgehend den publizierten Ergebnissen aus regenversauerten Weichwasserseen. Vermutlich wurde in den Tagebauseen der Säurestress, den die erhöhte Al-Konzentration von bis zu 0,6 mg/L verursachte, durch die ebenfalls erhöhte Ca-Konzentration kompensiert. / Numerous post-mining lakes are created by flooding the pits remaining from open-cast lignite mining in eastern Germany. They are typically large, oligo- or mesotrophic and only sparsely structured by macrophytes. Many of them are acidified or at risk of acidification. The aim of this study was (1) to determine the effects of lake morphology and habitat structure on the fish community of Lake Senftenberg, a large mesotrophic post-mining lake, and (2) to determine the acid tolerance of indigenous fish species under the hydrochemical conditions of geogenically acidified post-mining lakes. The most abundant fish species in Lake Senftenberg were Eurasian perch (Perca fluviatilis) and roach (Rutilus rutilus). Different size classes of both species segregated along a depth gradient within the littoral zone. Unvegetated shallow littoral areas (depth 1-3 m) were mainly used by juvenile perch, whereas juvenile roach and juvenile white bream (Blicca bjoerkna) preferred macrophyte stands. This indicates that the structural complexity of submersed macrophytes is not the key factor favouring perch over roach under mesotrophic conditions. Instead, low turbidity is probably the most important factor. The habitat choice of juvenile perch, roach and white bream is suggested to reflect different habitat selection strategies. Whereas habitat selection of juvenile perch is predominantly driven by maximisation of food consumption rates, juvenile roach and juvenile white bream aim at minimising predation risk. Consequently, they are much more dependent on structurally complex habitats. The critical lower pH-thresholds of the fish species investigated in this study were similar to the values derived from soft water lakes affected by acid rain. The deleterious effects of elevated Al-concentrations (up to 0.6 mg/L) in the post-mining lakes were probably mitigated by high Ca-concentrations.

Le reformage à la vapeur couplé à la sorption in-situ d’un composant du milieu réactionnel (sorption-enhanced steam reforming, SESR) est un procédé d’avant-garde qui permet simultanément la production d’hydrogène de très haute pureté et la capture du CO2. L'objectif principal de ce travail est le développement de nouveaux sorbants pour le CO2 applicables à hautes températures et l’étude de leur application dans SESR. Deux nouvelles méthodes de synthèse ont été proposées pour synthétiser du zirconate de lithium (Li2ZrO3), zirconate de sodium (Na2ZrO3) ainsi que des matériaux à base d’oxyde de calcium (CaO), trois catégories de sorbants capables de réagir avec le CO2 à hautes températures. L’application du Li2ZrO3 à la capture du CO2 a démontré une augmentation de l’activité du matériau produit par une nouvelle méthode de synthèse combinant un surfactant et traitement à ultrasons, comparativement au Li2ZrO3 préparé par une méthode avec surfactant seulement (sans ultrasons) ou par la méthode conventionnelle (mélange des composants en phase liquide). Néanmoins, pour des pressions partielles en CO2 inférieures à 0,75 bar, la faible cinétique de sorption du CO2 obtenue par le Li2ZrO3 limite son application au procédé SESR. En considérant l’amélioration des propriétés de sorption obtenue en appliquant la méthode combinée surfactant/ultrasons à la synthèse du Li2ZrO3, la même technique a été aussi appliquée à la synthèse du Na2ZrO3. Des résultats inattendus ont été pourtant obtenus. Le Na2ZrO3 développé par la nouvelle technique a été moins actif durant les cycles sorption/régénération que celui produit par la méthode conventionnelle, de par la faible résistance de sa structure poreuse à de très hautes températures. La nouvelle méthode de synthèse combinée surfactant/ultrasons a été aussi appliquée pour la synthèse de CaO stabilisé par du zirconium (Zr). Un rapport Zr/Ca de 0,303 a été trouvé optimal pour la production d’un sorbant présentant la meilleure stabilité et activité pour la capture de CO2. Dans les conditions sévères d’opération, les résultats ont généralement indiqué une capacité de sorption du CaO stabilisé supérieure à celle du CaO pure. Dans le but de réduire les coûts de production des sorbants, une source moins chère de CaO (calcaire naturel) a été utilisée en combinaison avec une nouvelle méthode de synthèse qui consiste dans l’acidification du calcaire par de l’acide citrique suivie par une calcination en deux étapes (argon et air). Doté d’une structure hautement poreuse, le CaO produit a révélé une stabilité nettement meilleure par rapport au calcaire, ainsi qu’une capacité accrue de sorption du CO2. La même technique de synthèse a été aussi utilisée pour développer plusieurs matériaux à base de CaO stabilisé par divers oxydes métalliques (Al, Zr, Mg et Y), afin d’améliorer la stabilité du sorbant dans les conditions opérationnelles sévères, particulièrement les hautes températures de régénération en présence de CO2. CaO stabilisé par l’aluminium (Al) ou le zirconium (Zr) a démontré une meilleure activité comparativement aux autres matériaux synthétisés, inclusivement dans des conditions sévères d’opération. L’application de ces deux types de sorbants au vaporeformage du méthane (SESMR) a été ensuite étudiée dans un réacteur à lit fixe. Pour minimiser les limitations diffusionnelles, deux matériaux hybrides sorbant-catalyseur ont été développés. NiO-CaO stabilisé par Zr, préparé par la méthode combinée surfactant/ultrasons, dont le contenu en NiO est de 20.5 % (masse) a montré une efficacité dans la production d’hydrogène de 92% lors du premier cycle de reformage, ce qui est remarquablement plus élevée que le rendement d’équilibre en H2 pour le procédé traditionnel de vaporeformage du méthane (SMR) ( 70%). La méthode acidification/calcination en deux étapes a été utilisée pour produire le deuxième matériau hybride (NiO-CaO stabilisé par Al). L’application du matériau contenant 25 % (masse) de NiO a conduit à une efficacité moyenne de production d’hydrogène de 97.3%, démontrant ainsi son grand potentiel pour le SESMR. Les résultats de ce projet de recherche ont clairement démontré que le procédé SESR est une alternative très avantageuse au procédé traditionnel de reformage à la vapeur (sans séparation in-situ de CO2) pour la production d’hydrogène de très haute pureté. Le matériau hybride sorbant-catalyseur NiO-CaO stabilisé par Al a démontré une excellente activité à long terme, en confirmant son potentiel élevé pour application dans le procédé SESMR. / Sorption-enhanced steam reforming (SESR) is a forefront technology to produce H2 clean fuel, which integrates both CO2 capture and H2 production in a single process. The main objective of this work is to develop novel high-temperature CO2 sorbents and to investigate their application in SESR operation. Special attention was given to lithium zirconate (Li2ZrO3), sodium zirconate (Na2ZrO3) and calcium oxide (CaO)-based materials, as most famous high temperature CO2 sorbents, by applying two novel synthesis techniques. The application of Li2ZrO3 in CO2 capture sorption showed an increase in activity of the material prepared by surfactant template/sonication method compared to Li2ZrO3 prepared by simple surfactant template method (without sonication) or conventional wet-mixing route. Nevertheless, porous Li2ZrO3 still suffered from slow kinetics of CO2 sorption at low CO2 partial pressure (below 0.75 bar), which can limit its application for SESMR operation. Taking into consideration the improvement of Li2ZrO3 sorption properties, the same surfactant template/sonication technique was then applied to develop porous Na2ZrO3. The behavior of the new developed Na2ZrO3 was unexpected. The samples prepared by surfactant template/sonication technique were found to be less active than the conventional Na2ZrO3 during cyclic operation, due to the low resistivity of the pore structure at the very high temperature treatment required for calcination. The same surfactant template/sonication was also applied to develop Zr-stabilized CaO sorbents. An optimum Zr/Ca ratio of 0.303 was found to maximize the stability and CO2 capture activity of the proposed Zr-stabilized CaO sorbent. The results generally showed a better CO2 capture ability of Zr-stabilized CaO sorbent in comparison with pure CaO in severe cyclic operating conditions. With the purpose of reducing the cost of sorbent production, a cheaper source of CaO (natural limestone) was also considered and a novel synthesis technique (limestone acidification by citric acid followed by two-step calcination (in Ar and air atmospheres)) was applied in order to prepare highly porous CaO structure with unique CO2 capture ability. The results revealed a much better stability and CO2 sorption activity of the developed sorbent compared to natural limestone. The same technique was employed to develop a number of metal oxide (Al, Zr, Mg and Y)-stabilized CaO sorbents in order to enhance sorbent stability in severe operating conditions, i.e., high temperature regeneration in the presence of CO2. Al and Zr-stabilized CaO showed the best activity during both mild and severe operating conditions. The performance of the developed CO2 sorbents providing the best performance in CO2 capture (Zr-stabilized and Al-stabilized CaO) were then investigated experimentally in the sorption enhanced steam methane reforming (SESMR) using a fixed-bed reactor. To minimize the diffusional limitations, a hybrid catalyst-sorbent was developed for both sorbents. The application of Zr-stabilized CaO-nickel hybrid catalyst with 20.5 wt% NiO loading, prepared by surfactant-template/sonication method, resulted in 92% H2 production efficiency for the initial SESMR cycle, which is remarkably higher than traditional steam methane reforming (SMR) equilibrium H2 yield (70 %). The second developed hybrid sorbent-catalyst (Al-stabilized CaO-NiO) was prepared using limestone acidification coupled with two-step calcination technique. The long-term application of the hybrid catalyst containing 25 wt% NiO led to an average H2 production efficiency of 97.3%, proving its high efficiency in the SESMR process. In summary, the results of this thesis show that the SESR process is as an efficient alternative of traditional steam reforming for production of highly pure H2. The Al-stabilized CaO-NiO hybrid sorbent-catalyst showed an excellent activity over long-term operation, thus confirming its very high potential for use in the SESMR process.

While Aluminium has lots of unique properties and is seen as a material of the future, its production and manufacturing has significant environmental impacts. For complex and dimensional shapes casting remains the main manufacturing method and in this study the environmental pressure of different casting techniques is compared. A screening LCA is conducted to determine the environmental impacts of plaster mould castings in a case study at the Ventana Hackås AB foundry in Mid Sweden. The findings are compared to models of sand, pressure die and lost wax castings, based on literature datasets. The most relevant factors for the environmental performance are identified as the production of the aluminium alloy and the amount and source of energy. For plaster mould castings additionally the plaster consumption is significant, while lost wax castings are dominated by the mould production and general processes. Under similar circumstances a relatively similar performance was found for all casting techniques except the lost wax process, which is at least 3 times more emission intensive. Of the remaining techniques pressure die castings performed the best and plaster mould castings the worst, but different sources of uncertainties have been identified in this comparison. In addition a carbon footprint interface is created based on these findings, to enable specific comparisons of different casting method setups. Customizable variables allow the adaptation of three scenarios to real world conditions. As the main influencing factors the aluminium alloy, source of electricity and casting technique have been identified. / <p>2018-10-10</p>

Les écosystèmes de dunes littorales offrent des opportunités pour l'étude des successions végétales et<br />des processus de colonisation. Le littoral dunaire atlantique français se développe sur environ 500<br />kilomètres du nord au sud. La végétation de dune grise est présente sur la partie de dune fixée, sous la forme de pelouse rase à plantes xérotolérantes. Un observatoire des mousses et des lichens sur neuf dunes non boisées du littoral atlantique de la France a été mis en place afin d'identifier les patrons de distribution des espèces de mousses et lichens en fonction des dynamiques du milieu.<br />L'analyse des patrons de distribution de la végétation sur la zone d'étude, le long d'un transect allant de la plage à la frange forestière, montre que les mousses et lichens se distribuent en cinq communautés à stratégies de vie identifiables par leurs traits biologiques ainsi que leur relation significative avec certains paramètres pédologiques. La position de chaque groupe dans certaines parties de dunes traduit des modifications dans la composition chimique de la couche superficielle du<br />substrat par la mise en évidence des gradients trophique, d'acidification et de décalcification de la plage à la dune boisée.<br />L'approche diachronique par le suivi des communautés de mousses et de lichens, ainsi que les relations entre les analyses de sol et les espèces et certains traits communs de réponse des espèces aux perturbations, suggèrent que la structure des communautés et les mécanismes participant à la fixation du milieu sont reliés aux conditions abiotiques du milieu qui varient en fonction du temps, aux stratégies de vie des espèces et aux perturbations. Les différentes communautés mises en évidence reflètent trois états de stabilité.<br />L'analyse des interactions biotiques au sein des communautés confirme que les lichens prennent une<br />part importante dans les processus de maturation de l'écosystème. De part leur zonation spatiale précise, leurs organisations et leurs rôles éventuels dans l'écosystème, les communautés bryolichéniques terricoles peuvent être considérées comme ayant un rôle clé de voûte dans le fonctionnement des dunes grises.<br />Les communautés bryolichéniques terricoles permettent de préciser une typologie des dunes littorales et d'évaluer leurs états dynamiques. Les résultats obtenus peuvent contribuer à obtenir un diagnostic écologique sur les dunes. Ils rendent possible des décisions de gestion du milieu et confirment l'intérêt du rôle indicateur des mousses et lichens pour le gestionnaire.

No description available.

This thesis compares the in situ water balance of common annual production systems (wheat, lupin, subclover and serradella) with a grazed perennial system (lucerne) at a site in the Avon Catchment, Western Australia. Using a physically-based water balance approach the value of a plant based solution in redressing the hydrological imbalance that has become a feature of much of the dryland agricultural region of Western Australia is investigated. The effectiveness of lucerne in providing greater available storage for buffering large rainfall events, as compared to the annual systems, is illustrated. Continued transpiration following out-of-season rainfall events maintains a larger available storage capacity. In contrast, the annual systems that are fallow over summer only withdrew a small fraction of water by soil evaporation between rainfall events. Under annual systems, the profile moisture store was sequentially increased to the extent that additional increments of rainfall could potentially contribute to deep drainage. A particular focus of this study has been to investigate the presence of soil constraints to root growth, and to assess how these constraints affect the water balance. A site survey indicated the soil penetration resistance was sufficient to impose a physical constraint to root growth. Published literature on the site shows soil acidity is also at a level imposing chemical constraints to root growth. A root growth model “Rootmodel”, for predicting root growth with and without soil constraints is examined in detail as a method for providing root growth parameters for inclusion into the numerical water balance model, SWIM based on Richard’s equation. Functions developed from “Rootmodel” adequately describe the effect of profile limitations to root growth, such as soil strength, moisture availability and temperature. Recommendations are made for inclusion of a growth suppressing function in “rootmodel” based on the chemical limitation of low pH. The effects of soil acidity on the root growth of several species is investigated experimentally and the resultant root data provided a reference point by which the simplified prediction of root growth built into SWIM could be adjusted using a linear reduction function. A similar linear reduction function is also employed to impose a physical constraint in the form of high penetration resistance.