Estimations of daily energy and nutrient availability based on nationally representative household budget survey data. The Data Food Networking (DAFNE) project

OBJECTIVE: To describe a cost-efficient method for estimating energy and nutrient availability using household budget survey (HBS) data. DESIGN: Four different approaches were tested and the results were compared with published nutrient intake data. The selected method was exemplarily applied in German and Greek data. SETTING: Germany, 1998; Greece, 1998/99. MATERIAL: Nationally representative HBSs. RESULTS: Comparisons showed that HBS-based estimates were generally close to intake data when results were presented as contributions to daily energy intake. Daily energy and protein availabilities were similar in Germany and Greece. Differences were observed in the availability of carbohydrates (German households reported a 5 percentage points higher contribution to daily energy availability) and lipids (Greek households recorded higher values for total fat, but lower values for saturated fat). Meat, added lipids and potatoes were important energy suppliers in Germany, whereas in Greece the first three energy suppliers were added lipids, cereals and meat. In both countries, meat, cereals, milk and cheese were important protein sources and cereals, potatoes, fruits and nuts contributed more than 60% of the daily carbohydrate availability. Added lipids were the major source of fat in the daily diet of both countries, but their contribution amounted to less than one-third in Germany and two-thirds in Greece. CONCLUSIONS: National HBS data can be used for monitoring and comparing nutrient availability among representative population samples of different countries. The ground is set for the development of a harmonised food composition table to be applied to HBS food data at international level.     

Effects of limestone and phosphorus on nutrient availability and coastal bermudagrass yield on an ultisol

Abstract

This field study was conducted to evaluate nutrient availability and Coastal bermudagrass [Cynodon dactylon (L.) Pers.] yield response to factorial combinations of applied limestone and P in a strongly acid (pH 4.7), infertile soil. Limestone was applied at rates of 0, 672, and 3808 kg ha^‐1 to a Lilbert loamy fine sand (loamy, siliceous, thermic, arenic Plinthic Paleudult). Phosphorus was applied at rates of 0, 30, 60, 90, 120, 240, and 480 kg P ha^‐1. Soil pH in the surface 15 cm initially increased to 6.2 in response to the high limestone rate, but subsequently declined due to N fertilization. Lime increased soil test P, Ca, and Mg and decreased K and Al. The efficiency of increasing soil test P with fertilizer P was low, but improved as a consequence of liming. Coastal bermudagrass yield increased by as much as 37 percent from P application. Maximum yield coincided with 10 to 15 mg kg^‐1 or greater soil test P and tissue P concentrations that ranged from 1.6 to 2.2 g kg^‐1. Lime Increased tissue Ca and Mg, but had no effect on plant P concentrations. Yield was unaffected by lime despite its positive effect on soil P and an apparent K‐Mg antagonism. Plant nutrients obtained from deep rooting of the bermudagrass into an argiilic horizon may have precluded any positive effect of lime on Coastal bermudagrass yield.     

Amelioration on some physical properties and nutrient availability of an exposed B horizon of red-brown earth

Abstract. Following removal of the upper 40 cm of soil, the physical properties of the exposed B horizon of a red-brown earth (Goulburn clay loam) were ameliorated using a combination of gypsum (5.4 ha⁻¹) and rye grass. Phosphorus (P), nitrogen (N) and potassium (K) fertilizers were added to improve nutrient availability. The ameliorated properties of the exposed B horizon were compared with those of equivalent depths from an adjacent intact profile of Goulburn clay loam.
Initially, during the establishment phase of the rye grass, the gypsum increased the electrolyte concentration in the 0–10 cm layer, and stabilized the soil surface against mechanical dispersion. After 18 months all the gypsum in the 0–10 cm layer had dissolved. However, in the presence of rye grass, the soil surface was no longer susceptible to dispersion by the mechanical impact of water. The rye grass improved soil physical properties mainly in the upper 20 cm of the exposed B horizon. Water-stable aggregation > 2000 μm and macroporosity increased, and bulk density and penetrometer resistance of the soil decreased.
Continuous applications of P, N and K fertilizers resulted in a gradual improvement in the nutritional properties of the exposed B horizon. However, because of the large phosphorus adsorption by the exposed clay, 300 kg P ha⁻¹ was required to provide sufficient available phosphorus in the 0–10 cm layer.     

Influence of food availability, predator density and forest fragmentation on nest survival of New Zealand robins

The decline of avian populations in fragmented landscapes is often attributed to a decrease in nest survival rates for species breeding within these habitats. We tested whether fragment size and connectivity, livestock grazing, predator density or invertebrate biomass were correlated with nest survival rates for an endemic New Zealand species, the North Island robin (Petroica longipes). Across three breeding seasons (2002-2005) daily nest survival rate for the 203 robin nests monitored in 15 forest fragments was 0.315 (SE 0.003), with nest survival rates increasing with invertebrate biomass (indexed with pitfall traps) and marginally decreasing with fragment size. Footprint tracking rates for exotic ship rats (Rattus rattus), which are likely to be the key nest predator, varied greatly among fragments, but were not a useful predictor of nest survival. We found no relationship between the number of fledglings per successful nesting attempt and invertebrate biomass. We conclude that fragment size and connectivity does not appear to be negatively influencing robin nest survival, potentially because of the already high impact that mammalian nest predators have in this unique system.     

Changes in enzyme activities and soil microbial community composition along carbon and nutrient gradients at the Franz Josef chronosequence, New Zealand

During primary succession, the abundance of carbon (C) and nitrogen (N) in soil increases, while phosphorus (P) declines. These changes in nutrient concentrations in organic matter are likely to play an important role in controlling enzyme-mediated nutrient mineralization. We examined how enzyme activity and efficiency changed with successional time in organic and mineral soils taken from the 120 000-year-old Franz Josef soil development sequence, New Zealand, and the relationship between enzyme activity and efficiency and soil nutrient concentrations. We found that the activity of enzymes involved in P mineralization increased with site age across the Franz Josef chronosequence, while the activity of enzymes regulating C and N mineralization declined in organic but not mineral soil. Sulfatase activity peaked at an intermediate-aged site, possibly indicating a transient period of S limitation. The activity of phosphatase enzymes was negatively correlated with the concentration of P in the soil, whereas activity of C-, N- and S-hydrolyzing enzymes was not strongly dependent on nutrient concentrations. When assessed as efficiency (activity per unit microbial biomass), there were strong patterns of increasing efficiency of P-, and decreasing efficiency of C- and N-hydrolyzing enzymes with site age. We suggest that activity patterns for C-, N- and S-hydrolyzing enzymes were obscured by simultaneous and opposing changes in enzyme efficiency and microbial biomass. In mineral soil, efficiency of enzymes was negatively correlated with soil nutrient availability. In contrast, in organic soil, efficiency of C-, N- and S-hydrolyzing enzymes was positively correlated with soil P, while efficiency of P-hydrolyzing enzymes was negatively correlated with soil P. The increase in efficiency of P-hydrolyzing enzymes, and decrease in efficiency of C-, N- and S-hydrolyzing enzymes with site age was accompanied by a shift in microbial community composition towards higher relative abundances of fungi. Changes in enzyme efficiency with site age are likely to be due to both constitutive differences in enzyme production, and down-regulation of enzyme expression.     

Effects of freeze–thaw cycles on microarthropods and nutrient availability in a sub-Arctic soil

It is predicted that Arctic regions may experience an increase in mean temperature in the future. This will affect the frequency of severe climatic events such as summer droughts and freeze–thaw cycles. In order to understand the impact of recurring freezing and thawing on soil organisms and their environment, intact plant–soil samples from the sub-Arctic were subjected to a series of such events. Springtail and mite species composition and abundance were monitored at intervals throughout the experiment. Furthermore, nutrient content and mobilisation in the soil and soil microbial biomass and nutrient content were examined.There was no conclusive evidence that recurring freeze–thaw events had a negative effect on the investigated soil faunal groups, and the treatment even seemed to stimulate the abundance of Acaridida. Respiration of soil subjected to 16 freeze–thaw cycles was low when kept at −2 °C and high when kept at +2 °C, indicating rapid response of microbial activity even after long exposure to low and fluctuating temperatures. Oribatida and Gamasida displayed a higher abundance in controls kept at −2 °C for up to 80 days, compared to controls at +2 °C and the freeze–thaw treatment. The Collembola were unaffected by the temperature treatments, but increased in abundance over time. The microbial C:N ratio increased after 40 days at −2 °C, indicating a higher degree of fungal dominance and lower tolerance of bacteria to constant freezing, but not to freeze–thaw. The decline in inorganic and microbial P during the experiment, and the proportionally stronger decrease of inorganic and microbial P than N in frozen soil compared to +2 °C soil, suggests that P is affected more than N mineralisation by freezing.     

Effects of earthworm casts and compost on soil microbial activity and plant nutrient availability

Vermicomposting differs from conventional composting because the organic material is processed by the digestive systems of worms. The egested casts can be used to improve the fertility and physical characteristics of soil and potting media. In this study, the effects of earthworm casts (EW), conventional compost (CP) and NPK inorganic fertilizer (FT) amendments on N mineralization rates, microbial respiration, and microbial biomass were investigated in a laboratory incubation study. A bioassay with wheat (Triticum aestivium L.) was also conducted to assess the amendment effects on plant growth and nutrient uptake and to validate the nutrient release results from the incubation study. Both microbial respiration and biomass were significantly greater in the CP treatment compared to EW treatment for the initial 35 days of incubation followed by similar respiration rates and biomass to the end of the study at 70 days of incubation. Soil NO₃⁻ increased rapidly in the EW and CP treatments in the initial 30 days of incubation, attaining 290 and 400 mg N kg⁻¹ soil, respectively. Nitrate in the EW treatment then declined to 120 mg N kg⁻¹ soil by day 70, while nitrate in the CP treatment remained high. While ammonium levels decreased in the CP treatment as nitrate level increased with increasing incubation time, a low level of ammonium was maintained in the EW treatment throughout the incubation. The wheat bioassay study included two additional cast treatments (EW-N and EW2) to have treatments with higher levels of N input. Plants grown with CP or FT treatment had a lower shoot biomass and higher shoot N content than in EW-N and EW-2 treatments, and also showed symptoms of salinity stress. Ionic strength and other salinity indicators in the earthworm cast treatments were much lower than in the CP treatment, indicating a lower risk of salinity stress in casts than in compost. All cast and compost amendments significantly increased wheat P and K uptake compared to either the non-amended control or the mineral fertilizer treatment. The results show that casts are an efficient source of plant nutrients and that they are less likely to produce salinity stress in container as compared to compost and synthetic fertilizers.     

Effect of soil carbohydrates on nutrient availability in natural forests and cultivated lands in Sri Lanka

Carbohydrates supply carbon sources for microbial activities that contribute to mineral nutrient production in soil. Their role on soil nutrient availability has not yet been properly elucidated. This was studied in forests and cultivated lands in Sri Lanka. Soil organic matter (SOM) fractions affecting carbohydrate availability were also determined. Soil litter contributed to sugars of plant origin (SPO) in croplands. The negative relationship found between clay bound organic matter (CBO) and glucose indicates higher SOM fixation in clay that lower its availability in cultivated lands. In forests, negative relationships between litter and sugars of microbial origin (SMO) showed that litter fuelled microbes to produce sugars. Fucose and glucose increased the availability of Cu, Zn and Mn in forests. Xylose increased Ca availability in cultivated lands. Arabinose, the main carbon source of soil respiration reduced the P availability. This study showed soil carbohydrates and their relationships with mineral nutrients could provide vital information on the availability of limiting nutrients in tropical ecosystems.     

Movement of aluminium as an inorganic complex in some podzolised soils,New Zealand

Chemical and mineralogical data are presented for three Spodosols (podzols) and a related Inceptisol (yellow-brown loam). Allophane with an Al/Si atomic ratio close to two is identified in the B horizons of all four soils, and minor amounts of imogolite are present in association with allophane in all but one soil where small-particle gibbsite occurs. Parent materials for these soils are essentially non-vitric. Allophane (Al/Si = 2) has been estimated quantitatively in all soils using oxalate-extractable Si (Si₀) and is selected clay fractions using both Si₀ and infrared spectroscopy. Maximum concentrations of allophane (Al/Si = 2) range from 5% to 18% of fine earth (< 2 mm) fractions and all occur in B horizons. Fe₀ values are low relative to Al₀ values except for the upper horizons of the Inceptisol. Al₀ values peak in B horizons and the ratio pyrophosphate-extractable Al to Al₀ decreases from about 1 in A and upper B horizons to 0.1–0.4 in lower B horizons.An interpretation of the data is consistent with recent proposals that the movement of Al in podzolisation is due primarily to the formation of inorganic complexes with Si. Chemical criteria for spodic horizons should be consistent with the total illuviation of Al and Fe (and perhaps Si), rather than just the organic-bound fraction of Al and Fe in these horizons as indicated by amounts in extractants such as pyrophosphate.     

Impact of an invasive clonal herb on epigaeic invertebrates in forest remnants in New Zealand

This study determines the impact of an invasive herbaceous weed Tradescantia fluminensis on invertebrates within three lowland podocarp/ broadleaved forest remnants in southern North Island, New Zealand. Epigaeic invertebrates were sampled within three Tradescantia-infested plots and three non-infested plots at each of three sites using pitfall traps. The abundance of invertebrates was reduced in Tradescantia plots compared with non-Tradescantia plots if Collembola and Acarina, the two most abundant and variable orders, are excluded (647±123 (mean±SE) compared with 1153±370), though this difference is not statistically significant. There was no difference if they were included (3897±2530 compared with 2505±1095). Five of the 23 orders collected were sorted into recognisable taxonomic units (RTUs). RTU richness was lower in Tradescantia plots compared with non-Tradescantia plots (39.7±5.5 compared with 51.7±8.9) though there was weak statistical support. Detrended correspondence analyses separated Tradescantia and non-Tradescantia plots within sites when based on RTUs, but not when based on orders/families. Overall, impacts of Tradescantia were apparent despite large differences in invertebrate assemblages among sites. The impact of Tradescantia could be a result of the weed's tall, dense vegetation structure and associated microclimate, relative to native ground covers.     

Nutrition and the burden of disease in New Zealand: 1997-2011

OBJECTIVE: To estimate the burden of disease due to selected nutrition-related risk factors (high total blood cholesterol, high systolic blood pressure, high body mass index (BMI) and inadequate vegetable and fruit intake) in 1997, as well as the burden that could potentially be avoided in 2011 if small, favourable changes in the current risk factor distribution were to occur. DESIGN: Data on risk factor levels, disease burden and risk associations were combined using comparative risk assessment methodology, a systematic approach to estimating both attributable and avoidable burden of disease. Disease outcomes assessed varied according to risk factor and included ischaemic heart disease, stroke, type 2 diabetes mellitus and selected cancers. SETTING: New Zealand. RESULTS: Approximately 4500 deaths (17% of all deaths) in 1997 were attributable to high cholesterol, 3500 (13%) to high blood pressure, 3000 (11%) to high BMI and 1500 (6%) to inadequate vegetable and fruit intake. Taking prevalence overlap into account, these risk factors were estimated jointly to contribute to approximately 11 000 (40%) deaths annually in New Zealand. Approximately 300 deaths due to each risk factor could potentially be avoided in 2011 if modest changes were made to each risk factor distribution. CONCLUSIONS: High cholesterol, blood pressure and BMI, as well as inadequate vegetable and fruit intake, are major modifiable causes of death in New Zealand. Small changes in the population distribution of these risk factors could have a major impact on population health within a decade.     

Erosion and soil productivity in Australia and New Zealand

Soil erosion assumes a different form in Australia and New Zealand. Sheet, rill and gully erosion are common in eastern Australia and wind erosion in the dry cropland areas. In New Zealand, mass movement dominates the erosion landscape but other kinds, including wind erosion, do occur. It is unclear how much of the mass movement is a natural phenomenon and how much is human-induced. In either case, it causes long-term reductions in soil productivity. A landmark analysis of the soil productivity loss due to land degradation was conducted by the Australian state of New South Wales. Water erosion was a greater problem than wind erosion, but soil structure deterioration was more costly than either kind of erosion.     

Site fidelity and along-shore range in Hector's dolphin, an endangered marine dolphin from New Zealand

To document site fidelity and the alongshore range of individual Hector's dolphins we analysed sightings of 32 photographically identified dolphins, each seen ?10 times at Banks Peninsula, New Zealand, between 1985 and 1997. The furthest two sightings of an individual were 106 km apart. All other individuals ranged over less than 60 km (x?=31.0 km, SE=2.43) of coastline. Gender did not significantly influence alongshore range (female x?=30.4 km, SE =3.21, n=18; male x?=27.4 km, SE=5.68, n=5). Site fidelity was high: for example, on average, individuals were seen in Akaroa Harbour for about two thirds of the years they were known to be alive. These data suggest that impacts on Hector's dolphins are most appropriately managed on a small spatial scale.     

Understorey biomass production and biological nitrogen fixation in an organic Apple orchard in Canterbury,New Zealand

Abstract

One of the basic requirements for sustainable management of soils is to ensure that soil fertility is maintained in a productive state and conditions so as to enable the soil to continue to provide viable economic yields with minimum degradation of soil quality and quantity. The practice of supplying nitrogen to fruit trees from biological nitrogen fixation by pasture legumes in the understorey vegetation of orchards is a sustainable means of maintaining soil fertility. Quantitative field measurements of amounts of biomass production and biological nitrogen fixation by three different kinds of understorey vegetation in an organic apple orchard in Canterbury, New Zealand was conducted over a period of two years. Results obtained showed that understorey herbage biomass production varied from 8 to 12 t ha^‐1 and biological nitrogen fixation varied from 118 to 126 kg N ha^‐1 over the period of two years. Nitrogen fixation was significantly correlated with clover dry matter production. Results were affected by seasons and understorey management practices.     

Holocene sediment budgets for upland catchments: The problem of soilscape model and data availability

This study presents a Holocene sediment budget for the upland catchment of the Speyerbach in the Palatinate Forest, southwestern Germany. The influences of both, data availability and the choice of an appropriate soilscape model on the sediment budget calculations are investigated. For budget calculations the spatial distribution of soils was derived from the soil map 1:50,000. Thickness values of soil truncation and colluvial burial were extracted from two soil data sets with varying information content. Data processing contained a disaggregation of the soil map with the help of land use data. In order to model the sediment budget a reference soil thickness (a so-called soilscape model), which represents the initial conditions is necessary. As upland soils are developed in periglacial solifluction sheets, the main solifluction sheet (MSS, “Hauptlage”) showing a constant thickness and being affected by soil forming processes was chosen.     

Iron availability from whey protein hydrogels: an in vitro study

The influence of whey protein hydrogel microstructure, filamentous versus particulate, on iron delivery was studied under different conditions, including simulated gastrointestinal conditions. Experiments were initially conducted to determine the impact of pH and enzymes on iron release. The results show that different iron release profiles can be obtained from filamentous and particulate gels. Particulate gels released more iron than filamentous gels at acidic pH, but the opposite was observed at alkaline pH. In the presence of pepsin at pH 1.2 or pancreatin at pH 7.5, both gel types showed increased protein hydrolysis, but only filamentous gels showed increased iron release, suggesting that matrix structure plays an important role in iron delivery. A dissolution test was carried out under gastrointestinal conditions to mimic the in vivo dissolution process. Filamentous gel released most of its iron during the intestinal phase of a simulated digestion, hence protecting iron during its transit in the gastric zone. Absorption of iron by the Caco-2 system, used to estimate intestinal absorption, revealed that filamentous gels favored intracellular iron absorption. These results suggest that filamentous gels show promise as matrices for transporting iron and promoting its absorption and therefore should be of major interest in the development of innovative functional foods.     

Race and food store availability in an inner-city neighbourhood

BACKGROUND: A growing body of research has shown that disparities in resources, including food stores, exist at the neighbourhood level and the greatest disparities are seen in minority neighbourhoods, the same neighbourhoods at increased risk of obesity and diabetes. Less is known about whether differences in availability of resources by African American or Latino race/ethnicity exist within a single minority community. OBJECTIVE: The present study examined whether census blocks either 75% African American (AA) or 75% Latino (L) are associated with food store availability, as compared with racially mixed (RM) census blocks, in East Harlem, New York. DESIGN/METHODS: A cross-sectional study utilising a walking survey of East Harlem was performed. Food stores were classified into: supermarkets, grocery stores, convenience stores, specialty stores, full-service restaurants and fast-food stores. RESULTS: One hundred and sixty-five East Harlem census blocks were examined; 17 were AA, 34 were L and 114 were RM. Of AA census blocks, 100% had neither supermarkets nor grocery stores. AA census blocks were less likely to have convenience stores (prevalence ratio (PR) = 0.25, 95% confidence interval (CI) 0.07-0.86) compared with RM census blocks. In contrast, predominantly L census blocks were more likely to have convenience stores (PR = 1.8, 95% CI 1.20-2.70), specialty food stores (PR = 3.74, 95% CI 2.06-7.15), full-service restaurants (PR = 1.87, 95% CI 1.04-3.38) and fast-food restaurants (PR = 2.14, 95% CI 1.33-3.44) compared with RM census blocks. CONCLUSIONS: We found that inequities in food store availability exist by race/ethnicity in East Harlem, New York. This has implications for racial/ethnic differences in dietary quality, obesity and obesity-related disorders.