Academic literature on the topic 'Templeton soil'

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Journal articles on the topic "Templeton soil"

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Di, HJ, and RA Kemp. "Variation in soil physical properties between and within morphologically defined series taxonomic units." Soil Research 27, no. 2 (1989): 259. http://dx.doi.org/10.1071/sr9890259.

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Eyre, Templeton and Wakanui series are morphologically defined taxonomic units which are used to partition alluvial soil variation across the Canterbury Plains near Lincoln College in New Zealand. The wider significance of the classification criteria is here assessed by quantifying the variability of physical properties of hydraulic significance ['field-saturated' hydraulic conductivity (Kfs), moisture content and bulk density] between and within the three taxonomic units. The overall effectiveness of the morphologically based classification system in partitioning variation in soil physical properties is considered by using analysis of variance. The classification of soils according to texture and mottling criteria is generally effective in separating soils in terms of the selected soil physical properties. Although some topsoil physical properties do not differ significantly between pairs of taxonomic units, all subsoil properties are clearly distinguishable between Templeton and Wakanui series. The differences are mainly attributable to spatial changes in soil texture and pore characteristics. Different amounts of variation in physical properties, however, are still present within each taxonomic unit. The variation in physical properties amongst the combined series taxonomic units is reduced to differing extents by the classification. More than half of the variance in moisture content at both topsoil and subsoil depths amongst Templeton and Wakanui taxonomic units, for instance, is accounted for by the classification, and is thus due to differences between the two series. Little contribution is made by the classification in reducing the heterogeneity of Kfs in topsoils. The classification is particularly effective in separating Wakanui from Templeton taxonomic units in terms of subsoil Kfs, an important property controlling water movement and storage.
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Webb, T. H., J. J. Claydon, and S. R. Harris. "Quantifying variability of soil physical properties within soil series to address modern land-use issues on the Canterbury Plains, New Zealand." Soil Research 38, no. 6 (2000): 1115. http://dx.doi.org/10.1071/sr99091.

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Lack of accurate data to estimate soil physical properties for soil types is limiting the wide application of simulation models to address modern environmental and land-use issues. In this study, systematic sampling of soil profiles for soil physical characteristics has provided an improved basis upon which to estimate a number of soil physical properties for 4 soil series. The selected soils form a soil drainage sequence on the post-glacial surface of the Canterbury Plains and vary from shallow sandy loam, well-drained soils to deep clay loam, poorly drained soils. Three profiles within 3 map units were sampled for each of 4 soil series. Three horizons in each soil profile were sampled for soil porosity values, particle size, and saturated and near-saturated hydraulic conductivity. Variability in all data, as shown by coefficient of variation, increased in the order: total porosity = field capacity < wilting point < total available water = clay content < readily available water < macroporosity < sand content < hydraulic conductivity. Hydraulic conductivity exhibited high variability within horizons, between profiles, and within soil series. Temuka subsoils had extremely high variability in saturated hydraulic conductivity and this could be explained by their coarse prismatic structure. Analysis of variance identified horizons that differed in soil physical properties between soil series. Horizons that do not differ between series may be given pooled soil property values for the pooled series. Total porosity, field capacity, wilting point, clay content, and near-saturated hydraulic conductivity had the greatest number of differences (60–70%) between series comparisons, while total available water had fewest differences (5%). The series with greatest differences in drainage class (Temuka compared with Eyre or Templeton soils) recorded the largest number of differences in water release characteristics and particle size. There were few differences between well-drained Eyre and moderately well-drained Templeton series. Subsoils of Eyre series differed in hydraulic conductivity from subsoils for the other 3 series, but few differences in hydraulic conductivity were found between horizons of Templeton, Wakanui, and Temuka series. Hydraulic conductivity estimates for these series can therefore be pooled.
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Vogeler, Iris, and Rogerio Cichota. "Effect of variability in soil properties plus model complexity on predicting topsoil water content and nitrous oxide emissions." Soil Research 56, no. 8 (2018): 810. http://dx.doi.org/10.1071/sr18080.

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Despite the importance of soil physical properties on water infiltration and redistribution, little is known about the effect of variability in soil properties and its consequent effect on contaminant loss pathways. To investigate the effects of uncertainty and heterogeneity in measured soil physical parameters on the simulated movement of water and the prediction of nitrous oxide (N2O) emissions, we set up the Agricultural Production Systems sIMulator (APSIM) for different soil types in three different regions of New Zealand: the Te Kowhai silt loam and the Horotiu silt loam in the Waikato region, and the Templeton silt loam in the Canterbury region, and the Otokia silt loam and the Wingatui silt loam in the Otago region. For each of the soil types, various measured soil profile descriptions, as well as those from a national soils database (S-map) were used when available. In addition, three different soil water models in APSIM with different complexities (SWIM2, SWIM3, and SoilWat) were evaluated. Model outputs were compared with temporal soil water content measurements within the top 75mm at the various experimental sites. Results show that the profile description, as well as the soil water model used affected the prediction accuracy of soil water content. The smallest difference between soil profile descriptions was found for the Templeton soil series, where the model efficiency (NSE) was positive for all soil profile descriptions, and the RMSE ranged from 0.055 to 0.069m3/m3. The greatest difference was found for the Te Kowhai soil, where only one of the descriptions showed a positive NSE, and the other two profile descriptions overestimated measured topsoil water contents. Furthermore, it was shown that the soil profile description highly affects N2O emissions from urinary N deposited during animal grazing. However, the relative difference between the emissions was not always related to the accuracy of the measured soil water content, with soil organic carbon content also affecting emissions.
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Magat, S. S., and K. M. Goh. "Effects of chloride fertilizers on yield and uptake of chloride, potassium and sodium by fodder beet (Beta vulgaris L.) in two New Zealand soils." Journal of Agricultural Science 111, no. 2 (October 1988): 207–16. http://dx.doi.org/10.1017/s0021859600083155.

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summaryThe effects of applications of sodium chloride (NaCl) and potassium chloride (KCl) ranging from 0 to 720 kg Cl/ha on the yield and uptakes of chloride (Cl) potassium (K) and sodium (Na) by fodder beet were studied in field experiments at two sites in New Zealand. At 360 kg Cl/ha applied, both NaCl (590 kg/ha) and KC1 (758 kg/ha) increased significantly yields of fresh roots, dry roots and fresh sugar content of fodder beet over the minus-Cl plants. Compared with the sulphate anion, chloride application stimulated K uptake in tops and roots. Results indicated that in the beet crop, uptake of K is enhanced with the presence or addition of Cl (as NaCl) compared with SO4 (as NaSO4).In both soils, total (tops and roots) uptakes of K, Cl, and Na were significantly correlated with fresh roots, dry roots and fresh sugar content. Multiple regression analyses showed that total K uptake was the main nutritional factor which determined yields of fresh and dry roots in the Templeton soil, whilst in the Wakanui soil total Cl uptake and total K+total Cl uptakes determined fresh root and dry root yields, respectively. In both soils, high Cl uptake was required for increased sugar yields.
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Nguyen, M. L., and K. M. Goh. "Distribution, transformations and recovery of urinary sulphur and sources of plant-available soil sulphur in irrigated pasture soil–plant systems treated with 35sulphur-labelled urine." Journal of Agricultural Science 122, no. 1 (February 1994): 91–105. http://dx.doi.org/10.1017/s0021859600065837.

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SUMMARYA field plot experiment of 271 days duration was conducted on New Zealand irrigated pastures, commencing in the summer (January) 1988, on a Templeton silt loam soil (Udic Ustochrept) by applying 35sulphur (35S)-labelled urine (250 μCi/g S with 1300 μg S/ml) to field plots (600 × 600 mm) at a rate equivalent to that normally occurring in sheep urine patches (150 ml/0·03 m2) to investigate the distribution, transformations and recovery of urinary S in pasture soil–plant systems and sources of plant-available soil S as influenced by the available soil moisture at the time of urine application and varying amounts of applied irrigation water. Results obtained showed that c. 55–90% of 35S-labelled urine was incorporated into soil sulphate (SO42−), ester SO42− and carbon (C)-bonded S fractions within the major plant rooting zone (0–300 mm), as early as 27 days after urine application. Hydriodic acid (Hl)-reducible and C-bonded soil S fractions showed no consistent trend of incorporation. On day 271, labelled-S was found in soil SO42−, Hl-reducible S and C-bonded S fractions to a soil depth of 500 mm, indicating that not only SO42− but also organic S fractions from soils and 35S-labelled urine were leached beyond the major rooting zone. A large proportion (c. 59–75%) of 35S-labelled urine was not recovered in pasture soil–plant systems over a 271-day period, presumably due to leaching losses beyond the 0–300 mm soil depth. This estimated leaching loss was comparable to that (75%) predicted using the S model developed by the New Zealand Ministry of Agriculture. The recovery of urinary S in soil–plant systems over a 271-day period was not affected by different amounts of irrigation water applied 7 days after urine application to soil at either 50 or 75% available water holding capacity (AWHC). However, significantly lower S recovery occurred when urinary S was applied to the soil at 25% AWHC than at field capacity, suggesting that urinary S applied at field capacity might not have sufficient time to be adsorbed by soil particles, enter soil micropores or be immobilized by soil micro-organisms. Both soil ester SO42− and calcium phosphate-extractable soil S in urine-treated soils were found to be major S sources for pasture S uptake. Labelled S from 35S-labelled urine accounted for c. 12–47% of total S in pasture herbage.
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Carey, P. L., V. J. Bidwell, and R. G. McLaren. "Chromium(VI) leaching from large undisturbed soil lysimeters following application of a simulated copper-chromium-arsenic (CCA) timber preservative." Soil Research 40, no. 2 (2002): 351. http://dx.doi.org/10.1071/sr01033.

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Copper, chromium, and arsenic (CCA) solutions are commonly used in New Zealand as a means of preserving softwood timbers such as Pinus radiata. With stock working solutions of CCA salts in timber treatment plants frequently 10&percnt; w&sol;v or more, there exists a potential for spillage and leaching of these compounds to groundwater. High concentrations of Cr(VI) (up to 52 mg Cr&sol;L) were found in the leachates of large undisturbed soil lysimeters where a Templeton sandy loam (Immature Pallic) had received surface applications of a simulated copper, chromium, and arsenic (CCA) timber preservative. Leaching was produced by using a combination of natural and imposed rainfall simulation over the lysimeters for a period of 102 days after CCA application. An average of 26&percnt; of the applied chromium was collected in the leachates after 102 days. Of the mean 74&percnt; of Cr(VI) still retained within the soil profile after leaching ended, almost half was located in the top 100 mm of the profile. No copper or arsenic was detected in any of the lysimeter leachates, with soil analysis indicating that these elements had been retained within the soil profile. In an incubation study, soil cores sampled from the same Templeton sandy loam and split into alternate 50-mm segments (to 450 mm) were stored at 10&ring;C for 102 days after addition of an identical CCA solution. These were periodically extracted for available chromium. Results showed that the reduction of dichromate&sol;chromate anions (Cr2O72–&sol;CrO42–) to the strongly sorbed chromic cation (Cr3&plus;) was largely first-order and greatest in surface layers where soil organic matter contents were largest. After 102 days, &lt;1&percnt; of the added Cr(VI) was still extractable in the 0–50 mm soil cores whilst ≈60&percnt; of Cr(VI) in the 400–450 mm cores (or deeper) was still extractable after the same period. A linear systems model comprising a series of conceptual mixing cells was used to describe the individual and mean Cr(VI) leaching breakthrough curves (BTCs). This State-Space Mixing Cell model proved effective in simulating the Cr(VI) leaching using first-order kinetics to quantify rate-limited local solute adsorption coupled to advective-dispersive transport. The solute mass involved in the model process was ≈30&percnt;. The bulk of the remaining 70&percnt; of applied dichromate was assumed to have undergone reduction to the non-mobile chromium cation. This study shows that there exists a significant potential for Cr(VI) to be a serious threat to groundwater in the event of a large uncontained spillage of a concentrated CCA solution. This potential can be significantly lessened if the Cr(VI) is reduced after retention in an organic matter rich layer.
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Carey, P. L., V. D. Bidwell, and R. G. McLaren. "Corrigendum to: Chromium(IV) leaching from large undisturbed soil lysimeters following application of a simulated copper-chromium-arsenic (CCA) timber preservative." Soil Research 40, no. 4 (2002): 715. http://dx.doi.org/10.1071/sr01033_co.

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Copper, chromium, and arsenic (CCA) solutions are commonly used in New Zealand as a means of preserving softwood timbers such as Pinus radiata. With stock working solutions of CCA salts in timber treatment plants frequently 10&percnt; w&sol;v or more, there exists a potential for spillage and leaching of these compounds to groundwater. High concentrations of Cr(VI) (up to 52 mg Cr&sol;L) were found in the leachates of large undisturbed soil lysimeters where a Templeton sandy loam (Immature Pallic) had received surface applications of a simulated copper, chromium, and arsenic (CCA) timber preservative. Leaching was produced by using a combination of natural and imposed rainfall simulation over the lysimeters for a period of 102 days after CCA application. An average of 26&percnt; of the applied chromium was collected in the leachates after 102 days. Of the mean 74&percnt; of Cr(VI) still retained within the soil profile after leaching ended, almost half was located in the top 100 mm of the profile. No copper or arsenic was detected in any of the lysimeter leachates, with soil analysis indicating that these elements had been retained within the soil profile. In an incubation study, soil cores sampled from the same Templeton sandy loam and split into alternate 50-mm segments (to 450 mm) were stored at 10&ring;C for 102 days after addition of an identical CCA solution. These were periodically extracted for available chromium. Results showed that the reduction of dichromate&sol;chromate anions (Cr2O72–&sol;CrO42–) to the strongly sorbed chromic cation (Cr3&plus;) was largely first-order and greatest in surface layers where soil organic matter contents were largest. After 102 days, &lt;1&percnt; of the added Cr(VI) was still extractable in the 0–50 mm soil cores whilst ≈60&percnt; of Cr(VI) in the 400–450 mm cores (or deeper) was still extractable after the same period. A linear systems model comprising a series of conceptual mixing cells was used to describe the individual and mean Cr(VI) leaching breakthrough curves (BTCs). This State-Space Mixing Cell model proved effective in simulating the Cr(VI) leaching using first-order kinetics to quantify rate-limited local solute adsorption coupled to advective-dispersive transport. The solute mass involved in the model process was ≈30&percnt;. The bulk of the remaining 70&percnt; of applied dichromate was assumed to have undergone reduction to the non-mobile chromium cation. This study shows that there exists a significant potential for Cr(VI) to be a serious threat to groundwater in the event of a large uncontained spillage of a concentrated CCA solution. This potential can be significantly lessened if the Cr(VI) is reduced after retention in an organic matter rich layer.
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Cameron, K. C., and H. J. Di. "Nitrogen leaching losses from different forms and rates of farm effluent applied to a Templeton soil in Canterbury, New Zealand." New Zealand Journal of Agricultural Research 47, no. 4 (December 2004): 429–37. http://dx.doi.org/10.1080/00288233.2004.9513611.

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Silva, R. G., K. C. Cameron, H. J. Di, N. P. Smith, and G. D. Buchan. "Effect of macropore flow on the transport of surface-applied cow urine through a soil profile." Soil Research 38, no. 1 (2000): 13. http://dx.doi.org/10.1071/sr99016.

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A field lysimeter experiment was conducted to determine the effect of macropore flow on the transport of surface-applied cow urine N through soil. The lysimeters (500 mm diameter by 700 mm depth) used for this experiment were collected from Templeton fine sandy loam soil (Udic Ustochrept), which had been under ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) pasture for 9–10 years. The effect of macropore flow on urine-N leaching was determined by leaching experiments under 0.5 kPa and 0 kPa water tensions (suctions) imposed on top of the lysimeter using a disc tension infiltrometer. The 0.5 kPa suction prevented soil pores >600 µm diameter from conducting water and solutes, while the 0 kPa suction allowed conduction under ‘field saturated’ condition. Pores >600 µm diameter transmitted about 98% of the total nitrogen (N) leached below 700 mm depth. The main form of N transmitted under 0 kPa was ammonium (NH4 -N), accounting for 10.5% of the total N applied at 0 kPa suction. This was significantly higher than the amount of NH 4 -N leached at 0.5 kPa suction, which accounted for 0.17% of N applied. The urea-N in the leachate reached 16 mg/L at 0 kPa suction, and accounted for 1.6% of the total N applied. No urea was detected in the leachate at the 0.5 kPa suction. The concentrations and amounts of nitrate (NO3 -N) leached were very low and did not differ between the two suctions. The forms and amounts of N leached were affected by the interactions of macropore flow and N transformations in the soil, and the environmental conditions during the two leaching events. From this work, it is recommended that stock should be removed 1–2 days before irrigation water is applied as this will allow animal urine to diffuse into soil micropores and thus decrease N leaching by macropore flow.
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Chakwizira, E., J. M. De Ruiter, S. Maley, S. J. Dellow, M. J. George, and A. J. Michel. "Water use efficiency of fodder beet crops." Proceedings of the New Zealand Grassland Association 76 (January 1, 2014): 125–34. http://dx.doi.org/10.33584/jnzg.2014.76.2969.

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Abstract In New Zealand, summer rainfall is unpredictable and usually insufficient to meet crop water requirements. The impact of water availability on yield potential of fodder beet (Beta vulgaris L.) is unknown. A single year, single site replicated field experiment investigating biomass production, water use (WU) and water use efficiency (WUE) was carried out on a deep Templeton silt loam soil at Lincoln in 2013. The experiment had four water treatments: 1: Rain fed control, 2: Full potential evapotranspiration (ETo) replaced weekly, 3: 50% of ETo replaced every 3 weeks and 4: 50% of ETo replaced weekly. Final dry matter (DM) yield differed with treatments, increasing from an average of 24 t/ha for the rain fed crops and those receiving 50% of ETo weekly to 28 t/ha for the full ETo replacement crops and those receiving 50% of ETo once every 3 weeks. Water use more than doubled with full irrigation compared with the rain fed crops (774 vs 316 mm). The WU for the intermediate crops was 483 mm. However, DM yield was higher for the treatment with 50% of ETo replaced every 3 weeks rather than weekly. Water use was related to DM yield and accounted for the observed variation (R2=0.75) in final yield. The WUE decreased with water supply, from 80 kg DM/ha/mm for the rain fed crops to 46 kg DM/ha/mm for the full ETo replacement treatments, and 64 and 57 kg DM/ha/mm for the 50% of ETo replaced weekly and every 3 weeks, respectively. Similar DM yield and marginal WUE for the full ETo treatments and those receiving 50% of ETo replaced every 3 weeks, meant that the most economic WUE was 57 kg DM/ha/mm. Although these results are from a single and site, they suggest that full ETo replacement was uneconomic in this type of soil and therefore partial irrigation to 50% of ETo replaced every 3 weeks may be the optimum for this type of soil. It is recommended to investigate similar treatments on shallow and stony soils. Keywords: Beta vulgaris L., evapotranspiration, water use, water use efficiency, water extraction pattern, water extraction depth.
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Dissertations / Theses on the topic "Templeton soil"

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Jiang, Shuang. "Bacterial leaching from dairy shed effluent applied to a fine sandy loam under flood and spray irrigations." Lincoln University, 2008. http://hdl.handle.net/10182/668.

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Land application of wastes has become increasingly popular, to promote nutrient recycling and environmental protection, with soil functioning as a partial barrier between wastes and groundwater. Dairy shed effluent (DSE), may contain a wide variety of pathogenic micro-organisms, including bacteria (e.g. Salmonella paratyphyi, Escherichia coli. and Campylobacter), protozoa and viruses. Groundwater pathogen contamination resulting from land-applied DSE is drawing more attention with the intensified development of the dairy farm industry in New Zealand. The purpose of this research was to investigate the fate and transport of bacterial indicator-faecal coliform (FC) from land-applied DSE under different irrigation practices via field lysimeter studies, using two water irrigation methods (flood and sprinkler) with contrasting application rates, through the 2005-2006 irrigation season. It was aimed at better understanding, quantifying and modelling of the processes that govern the removal of microbes in intact soil columns, bridging the gap between previous theoretical research and general farm practices, specifically for Templeton soil. This study involved different approaches (leaching experiments, infiltrometer measurements and a dye infiltration study) to understand the processes of transient water flow and bacterial transport; and to extrapolate the relationships between bacterial transport and soil properties (like soil structure, texture), and soil physical status (soil water potential ψ and volumetric water content θ). Factors controlling FC transport are discussed. A contaminant transport model, HYDRUS-1D, was applied to simulate microbial transport through soil on the basis of measured datasets. This study was carried out at Lincoln University’s Centre for Soil and Environmental Quality (CSEQ) lysimeter site. Six lysimeters were employed in two trials. Each trial involved application of DSE, followed by a water irrigation sequence applied in a flux-controlled method. The soil columns were taken from the site of the new Lincoln University Dairy Farm, Lincoln, Canterbury. The soil type is Templeton fine sandy loam (Udic-Ustochrept, coarse loamy, mixed, mesic). Vertical profiles (at four depths) of θ and ψ were measured during leaching experiments. The leaching experiments directly measured concentrations of chemical tracer (Br⁻ or Cl⁻) and FC in drainage. Results showed that bacteria could readily penetrate through 700 mm deep soil columns, when facilitated by water flow. In the first (summer) trial, FC in leachate as high as 1.4×10⁶ cfu 100 mL⁻¹ (similar to the DSE concentration), was detected in one lysimeter that had a higher clay content in the topsoil, immediately after DSE application, and before any water irrigation. This indicates that DSE flowed through preferential flow paths without significant treatment or reduction in concentrations. The highest post-irrigation concentration was 3.4×10³ cfu 100 mL⁻¹ under flood irrigation. Flood irrigation resulted in more bacteria and Br⁻ leaching than spray irrigation. In both trials (summer and autumn) results showed significant differences between irrigation treatments in lysimeters sharing similar drainage class (moderate or moderately rapid). Leaching bacterial concentration was positively correlated with both θ and ψ, and sometimes drainage rate. Greater bacterial leaching was found in the one lysimeter with rapid whole-column effective hydraulic conductivity, Keff, for both flood and spray treatments. Occasionally, the effect of Keff on water movement and bacterial transport overrode the effect of irrigation. The ‘seasonal condition’ of the soil (including variation in initial water content) also influenced bacterial leaching, with less risk of leaching in autumn than in summer. A tension infiltrometer experiment measured hydraulic conductivity of the lysimeters at zero and 40 mm suction. The results showed in most cases a significant correlation between the proportion of bacteria leached and the flow contribution of the macropores. The higher the Ksat, the greater the amount of drainage and bacterial leaching obtained. This research also found that this technique may exclude the activity of some continuous macropores (e.g., cracks) due to the difference of initial wetness which could substantially change the conductivity and result in more serious bacterial leaching in this Templeton soil. A dye infiltration study showed there was great variability in water flow patterns, and most of the flow reaching deeper than 50 cm resulted from macropores, mainly visible cracks. The transient water flow and transport of tracer (Br⁻) and FC were modelled using the HYDRUS-1D software package. The uniform flow van Genuchten model, and the dual-porosity model were used for water flow and the mobile-immobile (MIM) model was used for tracer and FC transport. The hydraulic and solute parameters were optimized during simulation, on the basis of measured datasets from the leaching experiments. There was evidence supporting the presence of macropores, based on the water flow in the post-DSE application stage. The optimised saturated water content (θs) decreased during the post-application process, which could be explained in terms of macropore flow enhanced by irrigation. Moreover, bacterial simulation showed discrepancies in all cases of uniform flow simulations at the very initial stage, indicating that non-equilibrium processes were dominant during those short periods, and suggesting that there were strong dynamic processes involving structure change and subsequently flow paths. It is recommended that management strategies to reduce FC contamination following application of DSE in these soils must aim to decrease preferential flow by adjusting irrigation schemes. Attention needs to be given to a) decreasing irrigation rates at the beginning of each irrigation; b) increasing the number of irrigations, by reducing at the same time the amount of water applied and the irrigation rate at each irrigation; c) applying spray irrigation rather than flood irrigation.
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Steiner, Laure D. "A Study of the fate and transport of estrogenic hormones in dairy effluent applied to pasture soils." Diss., Lincoln University, 2009. http://hdl.handle.net/10182/1306.

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The disposal of waste from agricultural activities has been recognised as a source of environmental contamination by endocrine disrupting chemicals (EDCs). The New Zealand dairy industry produces a large volume of dairy farm effluent, which contains EDCs in the form of estrogens. Most of this dairy farm effluent is applied onto the land for disposal. Groundwater and soil contamination by estrogens following waste application on the land have been reported overseas, but our understanding of the processes and factors governing the fate of estrogens in the soil is poor. Therefore the main goal of the present study was to better understand the fate and transport of estrogens, in particular 17β-estradiol (E2) and estrone (E1) in soil. In order to quantify E1 and E2 in drainage water and soil samples, chemical analysis by gas-chromatography mass-spectrometry (GC-MS) was carried out. This included sample extraction, sample clean-up through silica gel and gel permeation chromatography, and sample extract derivatisation prior to analysis. In order to develop a reliable method to extract estrogens from soil, research was conducted to optimise E1 and E2 extraction conditions by adjusting the number of sonication and shaking events, as well as the volume and type of solvent. Among five solvents and solvent mixtures tested, the best recovery on spiked and aged soil was obtained using an isopropanol/water (1:1) mix. A microcosm experiment was carried out to determine the dissipation rates of E2 and E1, at 8°C and at field capacity, in the Templeton soil sampled at two different depths (5-10 cm and 30-35 cm). The dissipation rates decreased with time and half-life values of 0.6-0.8 d for E1 and 0.3-0.4 d for E2 were found for the two depths studied. A field transport experiment was also carried out in winter, over three months, by applying dairy farm effluent spiked with estrogens onto undisturbed Templeton soil lysimeters (50 cm in diameter and 70 cm deep). The hormones were applied in dairy farm effluent at 120 mg m⁻² for E2 and 137 mg m⁻² for E1. The results of the transport experiment showed that in the presence of preferential/macropore flow pathways 0.3-0.7% of E2 and 8-13% of E1 was recovered in the leachate at the bottom of the lysimeters after 3 months, and 1-7% of the recovered E2 and 3-54% of the recovered E1 was leached within 2 days of application. These results suggest that leaching of estrogens via preferential/macropore flow pathways is the greatest concern for groundwater contamination. In the absence of preferential/macropore flow pathways, a significant amount (> 99.94%) of both hormones dissipated in the top 70 cm of soil, due to sorption and rapid biodegradation. Surprisingly, in all cases, estrogen breakthrough occurred before that of an inert tracer (bromide). This could not be explained by the advection-dispersion transport of estrogens, nor by their presence as antecedent concentrations in the soil. It was therefore suggested that colloidal enhanced transport of estrogens was responsible for the earlier breakthrough of estrogens and caused the leaching of a fraction of the applied estrogens to a soil depth of 70 cm. A two-phase model, adapted from a state-space mixing cell model, was built to describe the observed estrogen transport processes under transient flow. The model takes into account 3 transport processes namely, advection-dispersion, preferential/macropore flow and colloidal enhanced transport. This model was able to successfully describe the estrogen transport observed from the lysimeters.
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