Pumice Soils Research Articles

Pumice soil: a potential wetland substrate for treatment of domestic wastewater

Laboratory and fieldwork studies were carried out to evaluate the potential of pumice soil for use as a wetland substrate in wastewater treatment. The composition of pumice soil was analysed by x-ray fluorescence (XRF) and x-ray diffraction (XRD) techniques. Adsorption kinetic studies were carried out in a semi-batch recycle system. Fieldwork tests were carried out on Subsurface Flow Constructed Wetland (SSFCW) cells planted with Phragmites mauritianus and Vetiveria zizanioides. The results have shown that pumice soil composition contains among other elements Al, Ca, Fe and Mg, which are positive indicators for phosphorus adsorption. The main minerals observed by XRD were augite, hematite, and sodium titanium silicate. Phosphorus adsorption kinetics have shown that phosphorus is adsorbed on pumice soil following first order kinetics and the adsorption was highly influenced by mass transfer. Approximately 3% of the phosphorus was removed by plant uptake.

Clear-cutting reduces nitrate leaching in a pine plantation of high natural N status

Following the tree harvest, the biogeochemistry of a catchment is modified by changes in soil temperature and moisture, and nutrient cycling. We monitored soil-solution and stream-water chemistry, and soil properties in a Pinus radiata D. Don plantation in New Zealand before and after clear-cutting and replanting in 1997. The annual rainfall during the study was 1440–1860 mm. The soil was a 1800-year-old pumice soil of high natural N status; the catchment had received large inputs of volcanic N in rain, probably over the 1800 years since the pumice had been deposited. The leaching loss of nitrate-N was 28 kg ha −1 yr −1 in 1996, and then decreased sharply after clear-cutting to 3 kg ha −1 yr −1 in 1998 and <1 kg ha −1 yr −1 in 1999. Weed growth and soil microbial biomass increased during this time, and would have removed much of the N from soil solution in the upper soil layers. Although the catchment was small (8.7 ha), there was a 2-year lag until N decreased in stream-water; the losses of dissolved organic N to stream-water were low. There was no change in soil pH over the 4 years, but spring-water pH appeared to increase, which was consistent with the increase in bicarbonate that accompanied grass/weed growth. The export of cations (mmol c l −1) in the spring-water was Na>Ca>Mg=K as expected for rhyolitic pumice, and the total concentration was probably controlled by the accompanying anions. The export of anions was NO 3=Cl>SO 4=HCO 3 before harvest and HCO 3=Cl>SO 4=NO 3 after harvest.

Viral and chemical tracer movement through contrasting soils.

Land treatment of animal or human waste can result in chemical and microbial contamination of shallow ground water and/or water-ways. We investigated the fate of a host-specific Salmonella bacteriophage and a nonreactive chemical (Br-) tracer when applied to large intact lysimeter soil cores (500 mm diam. by 700 mm high). The soils included a poorly drained Gley Soil and well-drained Pumice, Allophanic, and Recent Soils. A depth of 30 mm of water containing the bacteriophage and Br- was applied to the soil at a rate of 5 mm h(-1) followed by up to about 1.8 pore volumes of simulated rainfall. Resulting leachates, collected continuously over at least one pore volume were analyzed for the bacteriophage and bromide (Br-) tracers. Bromide moved uniformly through the Pumice and Allophanic Soils with peak concentrations at about 1 pore volume, while the bacteriophage was detected only at trace levels or not at all. In contrast, both Br- and bacteriophage tracers moved rapidly through Gley and Recent Soils, appearing early in the leachate and then tailing off. Such flow patterns in the Gley and Recent Soils are indicative of bypass flow. Coarse soil structure in the Gley Soil, and finger-flow due to water repellency in the sandy Recent Soil are considered responsible for the observed bypass flow in these two soils. Allophanic and Pumice Soils have finer, more porous soil structure leading to a predominance of matrix flow over bypass flow. This study suggests vertical movement of viruses varies significantly with soil type.

Leaching of bacterial indicators of faecal contamination through four New Zealand soils

Land application of animal waste can result in bacterial contamination of shallow groundwater and/or waterways. Using 500-mm-diameter barrel lysimeters, we investigated the potential for bacterial indicators to leach through 4 New Zealand soils treated with dairy shed effluent (DSE). DSE was applied to soil lysimeters containing poorly drained Gley Soils (Te Kowhai and Netherton) and well-drained Allophanic (Waihou) and Pumice Soils (Atiamuri) at 50 mm/h, a typical field application rate used by farmers. Simulated rainfall was applied continuously at a rate of 5–10 mm/h, and leachate collected at a depth of 700 or 750 mm was analysed for faecal coliforms, Escherichia coli, and faecal enterococci. Bacterial indicators of faecal contamination readily moved through the Te Kowhai and Netherton soils, but not the Waihou and Atiamuri soils. Differential microbial movement was attributed to differences in soil structure. The poorly drained soils have coarse subsoil structures with macropores, favouring bypass flow. In contrast, the welldrained soils have a finer, more uniformly porous soil structure that minimised bypass flow and allowed matrix flow.

Changes in soil properties after application of dairy factory effluent to New Zealand volcanic ash and pumice soils

In field studies, we assessed the effects of irrigation with dairy factory effluent on the surface (0–10 cm) properties of 3 rhyolytic tephra soils. Horotiu and Te Kowhai soils had been irrigated for 22 years and Taupo soil for 2 years. Soil properties measured were: total organic C, total N, pH, bulk density, unsaturated hydraulic conductivity, moisture release characteristics, readily and totally available water, particle density, microbial C, soil respiration, mineralisable N, denitrification enzyme activity, and nitrification potential. Matched, non-irrigated areas were sampled for comparison. Average annual loadings (kg/ha) of C, N, and P since 1990 were 1120 kg N, 560 kg P, and 36 300 kg C onto Horotiu soil, and 760 kg N, 380 kg P, and 25 200 kg C onto the Te Kowhai soil. These post-1990 loadings were, on average, 23% less than pre-1990 values. Irrigation for 22 years onto the Horotiu and Te Kowhai soils caused no change, or a slight decrease, in total C and N in the topsoil, but microbial C and mineralisable N contents were more than doubled, and N cycling activity much increased. Soil pH was increased by up to 1.8 units. Unsaturated hydraulic conductivity was increased from 8.5 to 49.8 mm/h on the Horotiu soil, and from 6.5 to 29.0 mm/h on the Te Kowhai soil. Irrigation increased the volumetric water content between 10 and 100 kPa. Most of the changes in soil properties suggest current application rates and pasture production can be maintained or increased. The high loading and mineralisation of N in the irrigated soils raises concerns about potential leaching of nitrate; current management practices are targeted towards minimising N loadings from effluent.

Fractionation of cobalt and manganese in New Zealand soils

Many New Zealand soils are known to produce pastures deficient in cobalt (Co) for grazing ruminants; however, the development of an effective soil diagnostic test for Co is hindered by the lack of knowledge of the forms and distribution of Co in New Zealand soils. A sequential fractionation technique was used to determine the forms and concentrations of native and/or fertiliser derived soil Co in 18 New Zealand grassland topsoils, and the distribution and interrelationships of Co between fractions compared with those for manganese (Mn). Previous studies in other countries have indicated a strong association between Co and Mn in soils. For both Co and Mn, very small proportions were present in soluble and exchangeable forms, and the highest proportions of Co and Mn (mean 45.8% and 35.8%, respectively) were found in the residual fraction. However, there was little similarity overall in the distribution of Co and Mn between fractions. Multiple regression models, and the presence of substantial amounts of Co and Mn in iron (Fe) oxide fractions, indicate that the Fe content of the soil is much more important than Mn in influencing the distribution of Co in the soils. Exchangeable Co and Mn also appear highly sensitive to soil pH. Soil organic matter did not appear to have a major effect on the distribution of Co in soils, apart from Pumice Soils that have low concentrations of Fe and Mn.

Structure and Thermal Conductivity of Pumice Soils Deposited in Central Hokkaido

Structure and Thermal Conductivity of Pumice Soils Deposited in Central Hokkaido

Differences in maximum resistive bending moments of Pinus radiata trees grown on a range of soil types

The maximum resistive bending moments ( M b) were measured for 164 Radiata pine ( Pinus radiata D. Don) trees spanning a range of sizes and growing on six different New Zealand soil types. M b was significantly and positively correlated with tree height, diameter at 1.4 m (DBH) and stem volume with the latter explaining the greatest proportion of the variation in M b ( R 2=0.854). Trees with higher taper (lower ratio of tree height to DBH) had higher maximum resistive bending moments than trees with low taper. Both root plate diameter and root plate depth were significantly and positively associated with M b. For trees which failed by uprooting, stem volume, height:DBH ratio and root plate width explain over 91% of the variation in M b. Differences in M b were also found between soil types. Trees growing on northern yellow-brown earths and southern yellow-grey earths had significantly greater values of M b than those growing on yellow-brown pumice soils. A higher incidence of stem failure was also recorded on yellow-grey and yellow-brown earths. This type of failure could not be successfully modelled using elementary beam theory because of the breakdown of the uniform stress assumption and the presence of stem defects.

Fractal behaviour of some geological media

This paper describes the use of fractal geometry in determining the characteristics of some geological media, such as clayey and pumice soils. Attention is drawn to the determination of the specific surface of some clays of southern Italy and of pumice of the Vesuvius eruption of 79 a.d. The analysis proposed gives the Minkowski dimension of soils expressed by the power law, or the equation Mδ(F)≈Cδ–s; this is a dimensionless number. The values of Minkowski dimension obtained have been compared with the values obtained by physical methods (mercury porosimetry and the bottle helium test). The analyses conducted prove that, for the range of magnification adopted, the media examined behave as irregular or fractal sets.

Salt supplementation of dairy cows

Supplementation of salt to dairy cows on a pumice soil at Waikite, Rotorua gave a 12.8% increase in milk yield with unaltered composition. The response was immediate and occurred over a 3- month trial period. The result was obtained on ryegrass/clover pastures averaging 0.05% Na whereas the recommended concentration for dairy cows is 0.12% Na. Two methods of diagnosing Na deficiency were examined in the trial namely saliva Na: K ratios and pasture Na content. In the case of the former, practical sampling problems and a lack of a production response calibration indicates that of the two methods, pasture analysis will probably be the most simple and reliable means of diagnosing deficiency. Salt supplementation in a Na-deficient situation is likely to be economically very viable. If the 12.8% milk production response in the current trial was extended to the full lactation period this would give an additional income of $129/cow (at $3.50/kg milk solids) at a cost of $2.84/cow increased. Sodium deficiency is likely to become more prevalent in the future as outputs of Na on farms exceed inputs and potassium fertiliser continues to be applied at rates in excess of maintenance. Further work is required to determine critical Na levels for production responses, the best methods of supplementation, the rates of application required and how well salt dissolves and mixes with other drenches. Keywords: dairy cows, milk yield, salt supplementation, sodium response

Magnesium fertiliser dissolution rates in pumice soils under Pinus radiata

Application of Mg fertilisers has been suggested as a means of reducing the incidence of Mg deficiency of forest trees in New Zealand and Europe. The objective of this study was to determine the rates of dissolution of a range of Mg fertilisers applied to a pumice soil (Typic Udivitrand). The rate of fertiliser dissolution was little influenced by whether the fertiliser was applied directly on to the soil surface (litter removed) or on to the litter layer in a Pinus radiata plantation. Twenty-seven months since fertiliser application the mean (with and without litter) percentage of Mg dissolved was in the sequence: Epsom salts &gt; calcined magnesite 1–2 mm &gt; granmag (a partially acidulated and granulated calmag product) &gt; calcined magnesite 2–4 mm &gt; forestry grade dolomite. The specific dissolution rate constants (mg/cm2 .day of fertiliser) for the slowly soluble Mg fertilisers calculated using an elemental sulfur oxidation cubic model were 587 for calcined magnesite 1–2 mm, 426 for calcined magnesite 2–4 mm, 385 for granmag, and 18 for forestry grade dolomite. In a laboratory incubation study the elemental sulfur oxidation cubic model described the rate of dissolution of Mg fertilisers within narrow fertiliser particle size ranges. The specific fertiliser dissolution rate constants, however, increased with decreases in particle size, suggesting that the rate of dissolution depends on factors other than surface area when particle sizes varied widely. Slowly soluble, alkaline Mg fertilisers had a significant liming effect on the soil. They were more effective in increasing soil exchangeable Mg than soluble Mg salts over a long-period and therefore, they are better fertilisers for P. radiata.

A sequential extraction method for the determination of dissolution of magnesium from fertilizers applied to pumice soils

A major factor controlling the effectiveness of magnesium (Mg) fertilizers in correcting Mg deficiency in crops is their rate of dissolution in soils. The commonly used method of determining the rate of dissolution of fertilizers by measuring the increase in dissolved Mg in soils under field conditions can lead to errors because part of the dissolved Mg would normally be lost from the site of application by plant uptake and leaching. A more accurate method of estimating the rate of dissolution is to determine the amount of undissolved Mg and subtract it from the amount of Mg applied. A simple sequential extraction method was developed to measure the undissolved Mg in soils treated with a range of fertilizers with different solubilities. The method consisted of two 30‐minute extractions of a soil sample with 0.5M BaCl2‐TEA, pH 8.2 to determine dissolved Mg in the sample followed by a 1‐hour extraction with 0.5M HCl to determine difficulty‐soluble or slow‐release Mg, and finally an 18‐hour extraction with 2M HCl to determine undissolved Mg. The method gave nearly a 100% recovery of Mg applied in fertilizers to two pumice soils (Vitrands). The rates of dissolution of the fertilizers in the two soils were in the order of Epsom salts = fine magnesium oxide (calcined magnesite) > coarse magnesium oxide (calcined magnesite), coarse partially acidulated magnesium oxide (Granmag™), fine dolomitic limestone > fused magnesium phosphate.

Effect of calcined magnesite on soil and Pinus radiata foliage magnesium in pumice soils of New Zealand

Magnesium (Mg) deficiency is common in a number of forest regions in the world. It has been linked to a condition in P. radiata called ‘upper mid crown yellowing’ (UMCY) in New Zealand and ‘new type forest decline’ in Europe. Mg concentrations are low in many of New Zealand"s forest soils. With increases in the number of rotations and increased growth rates through tree breeding, Mg deficiency is expected to increase. This study was conducted to determine the fate of calcined magnesite (calmag) fertiliser applied at 150 kg Mg/ha at 2 sites in the Kaingaroa Forest near Rotorua, New Zealand. It also investigated the effectiveness of calmag in increasing the soil solution and soil exchangeable Mg in pumice soils and Mg concentrations in the pine needles, and in reducing the likelihood of UMCY 2 and 3 years after fertiliser application. In both sites and for both years of sampling the application of calmag fertiliser resulted in a significant increase in soil exchangeable and soil solution Mg in the 0–5 cm soil layer. Soil and soil solution pH had also been increased in the top 5 cm soil layer. Two years after application about 90% of the fertiliser applied had dissolved and about 70–80% of the Mg remained in a plant-available form (ammonium acetate exchangeable Mg) in the top 10 cm of soil. Calculations suggest that 3–10% of applied fertiliser had been lost due to leaching. Magnesium fertiliser application also resulted in significant reduction in the exchangeable K: Mg ratio and reduced exchangeable Al in the 0–5 cm soil layer. After 3 years, foliar Mg concentrations increased at all sites in the fertilised trees compared with the control trees, although differences were not yet significant. UMCY severity in the trees was also not significantly affected by the application of Mg fertiliser.

Some special geotechnical properties of pumice deposits

This paper describes the characteristics of pumice soils from the area of Mount Vesuvius and discusses sinking, watering and other geotechnical tests on pumice from a number of sites. Attention is drawn to the presence of both inter- and intra-particle voids within this material and appropriate modifications to the standard solid-water-air phase diagram are suggested to take account of this. The importance of understanding the structure of the pumice and its response to rainfall/ground water conditions is discussed in relation to both landslips and stabilisation works.

Relationship between pasture dry matter yield and soil Olsen P from a series of long‐term field trials

Forty‐six data‐sets from a series of 17 long‐term field trials measuring the effects of rates and forms of phosphate (P) fertiliser on pasture production and soil fertility in New Zealand were used to characterise the relationship between pasture dry matter (DM) yield in any year (expressed as relative yield, RY) and soil Olsen P test at the end of the annual DM measurement period. Average coefficients of variation in the measurement of these parameters were 7% and 17% for DM yield and Olsen P, respectively. The results failed to demonstrate that the RY at any site in any year could be reliably assessed from a common relationship between RY and the Olsen P test. However, the mean relationship did take the general “diminishing returns” form as expressed by the Mitscherlich equation, and as Olsen P levels increased the probability of low RY decreased. There was no evidence that RY increased with increase in Olsen P test values above 20, with the exception of the one yellow‐brown pumice soil in the series. The largest component of variability in the RY v. Olsen P relationship occurred within years within individual sites, reflecting inherent within site variability and treatment and measurement errors. Variability was also large between years within sites; this appeared to arise from erratic patterns of response within sites over time, possibly because of climatic, botanical, and edaphic fluctuations. The least variability in the RY v. Olsen P relationship arose from differences between sites. Soil pH, P retention, and rainfall did not significantly affect the relationship, but the yellow‐brown pumice site and sites with high DM production gave lower RY for any given Olsen P than other sites.

Accumulation of cadmium derived from fertilisers in New Zealand soils

Accumulation of cadmium was assessed by comparing 58 soil samples archived up to 50 years ago with present-day soils from the same sites. Mean levels of acid-extractable Cd have increased from 0.39 mg kg −1 to 0.85 mg kg −1 closely matching the amount of Cd applied in phosphate fertiliser. CaCl 2-extractable Cd has increased from 0.02 mg kg −1 to 0.11 mg kg −1, a greater percentage increase than for acid-extractable Cd. This may be attributed to added Cd being more mobile than native Cd. Cadmium levels have increased in Allophanic Soils, Brown Soils, Gley Soils, Organic Soils, Oxidic Soils, Pallic Soils, Pumice Soils, and Hydrothermal Recent Soils but not in Fluvial Recent Soils, which appear to have a lower Cd retention capacity.

Changes in Ponderosa Pine Site Productivity following Removal of Understory Vegetation

AbstractCompetition from understory vegetation for water and nutrients can limit productivity of young forest stands. Less is known of the effect of understory vegetation on long‐term stand growth or soil organic properties. The effect of understory vegetation on periodic annual increments (PAIs) of basal area, height, and volume for ponderosa pine (Pinus ponderosa Dougl.) in central Oregon at 4‐ or 5‐yr intervals was examined for a 35‐yr period. Soil C, N, and microbial biomass C (MBC) were also quantified after 32 and 35 yr with and without understory vegetation on a sandy loam pumice soil (Xeric Vitricryand). Five tree spacings, ranging from 2.0 to 8.0 m (154–2469 trees ha−1), in combination with two understory treatments (understory vegetation present or continuously absent) were installed in 1959. Total understory vegetation cover averaged 35% between 1959 and 1994 for treatments with understory vegetation present, and was dominated by three shrub species: antelope bitterbrush [Purshia tridentata (Pursh) DC.], greenleaf manzanita (Arctostaphylos patula Green), and snowbrush (Ceanothus velutinus Dougl. ex Hook.). Covariance analyses of PAIs for each successive interval were performed using appropriate stand parameters at the start of each interval as covariates. Tree growth was reduced by competing understory vegetation during the first 12 to 20 yr only; understory vegetation did not reduce the adjusted PAIs during the last 15 yr. Soil C and N were measured incrementally to a depth of 24 cm. Presence of understory vegetation resulted in greater C and N in the O horizon and upper 4 to 12 cm of mineral soil. Seasonal MBC, measured at 14‐d intervals from May to November, was greater when understory vegetation was present. The results suggest that understory vegetation plays an important role in maintaining soil quality.

Monitoring cobalt status - experiences in the central North Island

The requirement for 'cobalt (Co) of ruminants grazing pastures on the pumice soils of the Central Plateau was established in the late 1930s and Co topdressing to increase the Co intake of animals became commonplace from the mid-1950s. An on-farm survey in 1978-79 indicated that Co inputs could be halved because of adequate reserves of soil Co accumulated since the 1950s. However, the economic downturn in agriculture of the 1980s led to marked reductions in Co use. Follow-up surveys between 1991-93 indicated a general decline in soil and pasture Co levels. This decline was much more pronounced in areas with a poor history of Co topdressing. The 1991-93 survey results indicated a relationship between soil Co and pasture Co, Using probability analysis it was possible to indicate the soil Co level required to maintain a particular pasture Co concentration. Keywords: EDTA soil cobalt, fertiliser practice, pasture cobalt, stock health

Oversowing of five grass species and white clover on a Taupo hill country pumice soil

Abstract Methods of establishing perennial ryegrass (Lolium perenne L.), prairie grass (Bromus willdenowii Kunth), phalaris (Phalaris aquatica L.), cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.), and white clover (Trifolium repens L.) by oversowing on a hill country pumice soil near Taupo were investigated in spring 1982 and 1983. Four pre-sowing sward treatments (paraquat herbicide application, hard grazing by sheep, treading by sheep, or treading by cattle) were applied in two experiments. Populations of seedlings, tillers, and plants, and herbage growth, were monitored for 2 years after each sowing. Degree of sward suppression resulting from sward treatments was the main factor influencing establishment success. Hard grazing resulted in minimal suppression of resident sward growth and hence poor establishment (2% of sown grass seed). Sheep treading yielded an average establishment rate of 4% of sown seed. Cattle treading removed most of the resident vegetation and resulted...

Utilisation of wastes as fertilisers with particular emphasis on the Bay of Plenty region

Estimates of the wastes produced in the Bay of Plenty region indicate that 22 million m' (tonnes) is produced annually. The main contributors to waste production are the dairy industry (shed, factory),municipal sewage, pig, poultry, meatworks, kiwifruit, fishing and pulp and paper industries. In fertiliser terms these wastes are valued at $7.7 million. In addition the timber industry produces &gt; 1 million tonnes of timber residues (sawdust, bark, woodchips) approximately 20% of which is currently dumped. Wastes, when recycled back on to the land, offer a potential source of nutrients to enhance pasture and crop production. In addition organic wastes provide a source of organic matter which may have beneficial effects on the physical properties of soils. Research results indicate that pumice soils are well suited to the application of wastes. Some general recommendations are given for the use of wastes in dairying, orcharding and cropping situations. Three factors are considered important for the successful utilisation of wastes (a) application rates need to be balanced to the nutrient needs of the soil-plant system (b) safeguards in the form of regular chemical monitoring of the effluent, soil, plant and animal need to be implemented, and(c) the economics of using the waste materials must be favourable to the farmer and orchardist. The principle of the producer of the waste paying for its safe disposal or utilisation needs to be adopted in New Zealand as it has in many overseas countries. Keywords nutrients, organic matter, waste recycling, pumice soils, fertiliser value