Aquaculture Farm Food Safety and Diseases Risk Assessment (AquaFRAM): Development of a spreadsheet tool for salmon farms

Atlantic salmon (Salmo salar) is the most significant aquaculture species in Europe, both in terms of production and economic value, with Norway, followed by Scotland and Ireland as the three major European producers. The objective of the present study was to develop a spreadsheet tool for aquaculture farm-food safety and diseases risk assessment (AquaFRAM) for salmon farms in the UK, (and possibly more widely) to encourage farms to assess potential hazards and diseases. AquaFRAM functions primarily as a self-assessment risk ranking and risk-learning tool to determine the potential of farm food safety hazards, diseases and the level of possible risk for contamination and infections. AquaFRAM has been developed using MS Excel software utilising a qualitative risk assessment approach for farmers to evaluate their food safety practices and diseases on their farms. The risk assessment is based on the risk matrix of frequency of likelihood × severity, where the farmers can judge the likelihood of the hazards occurring on their farm based on given examples or scenarios. Grounding of the model, based on severity scoring is predicated on relevant reports in the literature and expert opinion derived from a separate Delphi study. The AquaFRAM Tool has since been tested on 9 salmon companies throughout UK. All of the farms which tried and tested the AquaFRAM Tool reported it being farmer-friendly and practical. It was highlighted that the current tool focused mainly on risk reduction and not risk elimination. However, such farm food safety and diseases risk assessment tool would be helpful, and certainly timely, to further encourage farms to assess potential hazards and diseases. It is also appropriate for educational and training of full-time and seasonal farm workers.     

Relationship between sensory and NIR spectroscopy in consumer preference of table grape (cv Italia)

A combination of near infrared spectroscopy (NIR) instrumental measurements and sensory analysis was investigated to predict solids soluble content (SSC, assessed as Brix) and to classify preference in table grape cv Italia. SSC was monitored in each berry of whole bunches in order to evaluate intra-bunch distribution and variability. NIR spectra were recorded in the spectral region 12,000–4000 cm⁻¹ (833–2500 nm) using a set of 682 berries. The Partial Least Square (PLS) model based on cross-validation provided acceptable value for the main statistical parameters (coefficient of determination of cross-validation, r²: 0.85; standard error of cross-validation, SECV: 1.08; residual predictive deviation, RPD: 2.6) and was confirmed by external validation performed with 115 independent berries (coefficient of determination of prediction, r_p²: 0.82; standard error of prediction, SEP: 0.83). For consumer testing, the selected PLS model was used to predict the Brix value in 400 berries and Discriminant Analysis (DA) was then carried out to classify berries in terms of preference by relating NIR data to consumer judgment. The three defined preference clusters of berries were fully classified obtaining 100% membership. In cross-validation the value decreased especially for class 1 (78.5%) and 3 (75%) whereas class 2 obtained comparable values (98.7%). According to our results, NIR technology appears to be a promising technique for predicting SSC and obtaining information with regard to consumer preference in ‘Italia’ table grape for application of efficient and low cost on-line instruments in the fruit industry.     

Effects of elevated atmospheric CO2 on grain quality of wheat

Wheat (Triticum aestivum L.) is one of the most important agricultural crops worldwide. Due to its high content of starch and unique gluten proteins, wheat grain is used for many food and non-food applications. Although grain quality is an important topic for food and feed as well as industrial processing, the consequences of future increases in atmospheric carbon dioxide (CO₂) concentrations on quality parameters such as nutritional and bread-making rheological properties are still unclear. Wheat productivity increases under CO₂ enrichment. Concomitantly, the chemical composition of vegetative plant parts is often changed and grain quality is altered. In particular, the decrease in grain protein concentration and changes in protein composition may have serious economic and health implications. Additionally, CO₂ enrichment affects amino acid composition and the concentrations of macro- and micro-elements. However, experimental results are often inconsistent. The present review summarises the results from numerous CO₂ enrichment experiments using different exposure techniques in order to quantify the potential impacts of projected atmospheric CO₂ levels on wheat grain yield and on aspects of grain composition relevant to processing and human nutrition.     

Yield and water consumption characteristics of wheat/maize intercropping with reduced tillage in an Oasis region

Higher irrigation quota for conventional farming causes substantial conflicts between water supply and demand in agriculture, and wind erosion near soil surface is one of the major causes of farmland degradation and desertification in arid areas. This research investigated the effect of the amounts of irrigation in combination with tillage practices on soil evaporation (E), water consumption (ET) characteristics, and grain yield performance and water use efficiency (WUE) for wheat (Triticum aestivum L.) intercropped with maize (Zea mays L.) in strip planting in an Oasis region. The field experiment, conducted at Wuwei station during 2008–2010, had two tillage systems (reduced tillage with wheat stubble retention vs. conventional tillage without stubble retention), and three (low, medium, and high) levels of irrigation, in a randomized complete block design. Averaged across three years, soil evaporation with medium and high levels of irrigation was 6.8% and 5.4% greater than that with low level of irrigation, respectively. Total water consumption of wheat/maize crops under the medium and high irrigation levels was 8.5% and 18.5% greater, respectively, than that under low irrigation. However, grain yields were similar under the medium and high levels of irrigation, so was WUE. The effect of tillage on the wheat/maize intercropping was inconsistent across years or among treatments: soil moisture at harvest was 3.0–7.6% greater in the fields with reduced tillage compared with those with conventional tillage in 2008 and 2009, but no difference was found in 2010; the E/ET ratio of reduced tillage was 9% lower than the ratio under conventional tillage in 2008, 3% higher in 2010, but no difference between the two tillage systems in 2009. Across three years, there was a general trend that the WUE of the wheat/maize intercropping system with reduced tillage was greater (by 4–11%) than that with conventional tillage. We conclude that a medium level of irrigation is sufficient to achieve crop yields and WUE equivalent to those under high level of irrigation, provided that a reduced tillage practice is applied to the wheat/maize intercropping in Oasis areas.     

Postharvest physiology of ‘Aroma’ apples in relation to position on the tree

The effects of fruit position within the canopy on the onset of the respiratory climacteric and the rise in ethylene production as well as changes in peel colour and chemical composition were studied in apples (Malus x domestica Borkh. cv. Aroma) during ripening in normal air at 20 °C for 6–8 weeks over two crop seasons. The commencement of the rise in both CO₂ and ethylene production was equal independent of fruit position but the peak of ethylene was behind that of CO₂ with a lag of several days. While the climacteric ethylene peak was considerably higher in shaded inside apples, the internal ethylene concentration was at the same level independent of canopy position. During maturation on the tree outside fruit developed a red peel colour while inside fruit remained green. Outside fruit had a higher content of dry matter, soluble solids and soluble sugars but a somewhat lower amount of titratable acidity than inside fruit. High summer temperatures in the second year resulted in a significantly higher content of soluble solids and organic acids independent of fruit position but diminished the soluble solids difference between outside and inside fruit and increased the difference in malic and citric acid concentrations. High summer temperatures also increased the difference in peel colour between outside and inside fruit. Independent of canopy position, the soluble solids concentrations remained unchanged during ripening while the amounts of sucrose as well as malic acid and the titratable acidity decreased with a concomitant rise in the cell sap pH. The higher content of soluble sugars and a somewhat lower amount of titratable acidity in outside red-coloured apples probably contribute to improved fruit quality but the difference seems to be strongly dependent on the growing conditions, especially the sum of heat units.     

Nitrite transformations in an N-saturated forest soil

Nitrite dynamics could be highly associated with forest N cycles. However, they have often been overlooked mainly because of the experimental difficulties that occur owing to chemical reactive nature of NO₂⁻. We investigated NO₂⁻ dynamics in an N-saturated forest soil with a recently developed method using ¹⁵N. Soils were aerobically incubated for 145 h after ¹⁵NO₂⁻ addition, and changes in ¹⁴N and ¹⁵N concentrations of NO₂⁻, NO₃⁻, NH₄⁺, and dissolved organic N (DON) were monitored. Simultaneous production and consumption of NO₂⁻ were observed. The turnover rate of NO₂⁻ was even faster than that of NH₄⁺ and NO₃⁻ calculated in other studies. Of the added ¹⁵NO₂⁻, 28.5% was oxidized to NO₃⁻ and 17.8% was incorporated into the DON pool within 4 h. The remainder might be emitted as gas or fixed by insoluble soil organic matter. Our results suggested that rapid NO₂⁻ turnover could be a major driving force for N transformations in forest soil.     

Dynamics of methanogenesis and methanotrophy in tropical paddy soils as influenced by elevated CO2 and temperature interaction

Response of methanogenesis and methanotrophy to elevated carbon dioxide (CO₂) could be affected by changes in soil moisture content and temperature. In soil microcosms contained in glass bottles and incubated under laboratory conditions, we assessed the impact of elevated CO₂ and temperature interactions on methanogenesis and methanotrophy in alluvial and laterite paddy soils of tropical origin. Soil samples were incubated at ambient (370 μmol mol⁻¹) and elevated (600 μmol mol⁻¹) CO₂ concentrations at 25, 35 and 45 °C under non-flooded and flooded conditions for 60 d. Under flooded condition, elevated CO₂ significantly increased methane (CH₄) production while under non-flooded condition, only marginal increase in CH₄ production was observed in both the soils studied and the increase was significantly enhanced by further rise in temperature. Increased methanogenesis as a result of elevated CO₂ and temperature interaction was mostly attributed to decreased soil redox potential, increased readily mineralizable carbon, and also noticeable stimulation of methanogenic bacterial population. In contrast to CH₄ production, CH₄ oxidation was consistently low under elevated CO₂ concentration and the decrease was significant with rise in temperature. The low affinity and high affinity CH₄ oxidation were faster under non-flooded condition as compared to flooded condition. Admittedly, decreased low and high affinity CH₄ oxidation as a result of elevated CO₂ and temperature interaction was related to unfavorable lower redox status of soil and the inhibition of CH₄-oxidizing bacterial population.     

Saltcedar Water Use: Realistic and Unrealistic Expectations

Saltcedar (Tamarix spp.) is a widespread invasive plant found in riparian corridors and floodplains in 16 western states. In addition to being associated with such problems as increased soil salinity and decreased plant diversity, saltcedar has been reported to be a prolific water user. Popular press articles widely report that each individual saltcedar tree can use as much as 757 L (200 gallons) per day. Consequently massive control and removal efforts are underway to reduce transpirational water loss and increase water salvage for arid and semiarid environments. Although the potential economic benefits of these control efforts are touted, it has not been proven whether such water savings are possible on a stream level. The original citation for the 757-L estimate does not list the experimental design or techniques used to arrive at this value. We use three lines of evidence—peer-reviewed scientific literature, sap flux rates and sap wood area, and potential evaporation rates—to demonstrate the improbability that saltcedar, or any other woody species, can use this much water per tree on a daily basis. A more realistic estimate of maximum tree-level daily water use derived from sap flux measurements would be < 122 L · d^-1 (32.2 gallons). Estimates of water salvage would be grossly overestimated using the popular water use value (757 L · d^-1), and economic benefits from saltcedar control based solely on water salvage are questionable.