Nutrient input and removal trends for agricultural soils in nine geographic regions in Arkansas

Knowledge of the balance between nutrient inputs and removals is required for identifying regions that possess an excess or deficit of nutrients. This assessment describes the balance between the agricultural nutrient inputs and removals for nine geographical districts within Arkansas from 1997 to 2001. The total N, P, and K inputs were summed for each district and included inorganic fertilizer and collectable nutrients excreted as poultry, turkey, dairy, and hog manures. Nutrients removed by harvested crops were summed and subtracted from total nutrient inputs to calculate the net nutrient balance. The net balances for N, P, and K were distributed across the hectarage used for row crop, hay, pasture, or combinations of these land uses. Row-crop agriculture predominates in the eastern one-third and animal agriculture predominates in the western two-thirds of Arkansas. Nutrients derived from poultry litter accounted for >92% of the total transportable manure N, P, and K. The three districts in the eastern one-third of Arkansas contained 95% of the row-crop hectarage and had net N and P balances that were near zero or negative. The six districts in the western two-thirds of Arkansas accounted for 89 to 100% of the animal populations, had positive net balances for N and P, and excess P ranged from 1 to 9 kg P ha(-1) when distributed across row-crop, hay, and pasture hectarage. Transport of excess nutrients, primarily in poultry litter, outside of the districts in western Arkansas is needed to achieve a balance between soil inputs and removals of P and N.     

Innovation in environmental analysis

As the EU launches its latest 17 billion research programme, which includes significant funding for environmental research, JEM takes a look at the trends in and dynamics of innovation in environmental analysis.     

Aquacultural development in tropical Asia

Differences between inland and coastal aquacultural production systems in Asia are discussed in terms of market orientation, resource allocation and property rights, and scale of operations. The production of shrimp grown in coastal brackish water ponds has featured prominently in aquacultural development programmes in Asia. Emphasis placed on capital-intensive shrimp production for export, however, has distracted attention from the potential of inland freshwater aquaculture to generate employment opportunities for rural people and food production for domestic consumers. The paper concludes with a discussion of an alternative policy direction for promoting aquacultural development on a socially sound basis, recognizing the need to balance equity and human nutrition with profitability and foreign exchange earnings.     

Adaptation for crop agriculture to climate change in Cameroon: Turning on the heat

The Cameroonian agricultural sector, a critical part of the local ecosystem, is potentially vulnerable to climate change raising concerns about food security in the country’s future. Adaptations policies may be able to mitigate some of this vulnerability. This article investigates and addresses the issue of selected adaptation options within the context of Cameroonian food production. A methodology is applied where transient diagnostics of two atmosphere–ocean general circulation models, the NASA/Goddard Institute GISS and the British HadCM3, are coupled to a cropping system simulation model (CropSyst) to simulate current and future (2020, 2080) crop yields for selected key crops (bambara nut, groundnut, maize, sorghum, and soybean) in eight agricultural regions of Cameroon. Our results show that for the future, substantial yield increases are estimated for bambara groundnut, soybean and groundnut, while little or no change or even decreases for maize and sorghum yields, varying according to the climate scenario and the agricultural region investigated. Taking the “no regrets” principle into consideration, we explore the advantages of specific adaptation strategies specifically for three crops viz. maize, sorghum and bambara groundnut, under GISS A2 and B2 marker scenarios only. Changing sowing dates may be ineffective in counteracting adverse climatic effects because of the narrow rainfall band that strictly determines the timing of farm operations in Cameroon. In contrast, the possibility of developing later maturing new cultivars proved to be extremely effective in offsetting adverse impacts, giving the highest increases in productivity under different scenario projections without management changes. For example, under climate change scenario GISS A2 2080, a 14.6% reduction in maize yield was converted to a 32.1% increase; a 39.9% decrease in sorghum yield was converted to a 17.6% increase, and for bambara groundnut (an under-researched and underutilised African legume), yields were almost trebled (37.1% increase above that for sowing date alone (12.9%)) due to increase length of growing period and the positive effects of higher CO₂ concentrations. These results may better inform wider studies and development strategies on sustainable agriculture in the area by providing an indication as to the potential direction in shifts in production capabilities. Our approach highlights the benefit of using models as tools to investigate potential climate change impacts, where results can supplement existing knowledge. The results provide useful guidance and motivation to public authorities and development agencies interested in food security issues in Cameroon and elsewhere.     

Soil C storage as affected by tillage and straw management: An assessment using field measurements and model predictions

Soil tillage and straw management are both known to affect soil organic matter dynamics. However, it is still unclear whether, or how, these two practices interact to affect soil C storage, and data from long term studies are scarce. Soil C models may help to overcome some of these problems. Here we compare direct measurements of soil C contents from a 9 year old tillage experiment to predictions made by RothC and a cohort model. Soil samples were collected from plots in an Irish winter wheat field that were exposed to either conventional (CT) or shallow non-inversion tillage (RT). Crop residue was removed from half of the RT and CT plots after harvest, allowing us to test for interactive effects between tillage practices and straw management. Within the 0–30 cm layer, soil C contents were significantly increased both by straw retention and by RT. Tillage and straw management did not interact to determine the total amount of soil C in this layer. The highest average soil C contents (68.9 ± 2.8 Mg C ha^?1) were found for the combination of RT with straw incorporation, whereas the lowest average soil C contents (57.3 ± 2.3 Mg C ha^?1) were found for CT with straw removal. We found no significant treatment effects on soil C contents at lower depths. Both models suggest that at our site, RT stimulates soil C storage largely by decreasing the decomposition of old soil C. Extrapolating our findings to the rest of Ireland, we estimate that RT will lead to C mitigation ranging from 0.18 to 1.0 Mg C ha^?1 y^?1 relative to CT, with the mitigation rate depending on the initial SOC level. However, on-farm assessments are still needed to determine whether RT management practices can be adopted under Irish conditions without detrimental effects on crop yield.     

Is research keeping up with changes in landscape policy? A review of the literature

Several innovative directions for landscape policy development and implementation have emerged over recent years. These include: (i) an expansion of scope to include all landscape aspects and landscape types, (ii) an increased emphasis on public participation, (iii) a focus on designing measures appropriate for different contexts and scales, and (iv) encouraging support for capacity-building. In this paper, we evaluate the extent to which these policy directions are reflected in the practice of academic landscape research. We evaluate all research papers published in three leading landscape journals over six years, as well as published research papers relating directly to the European Landscape Convention. The latter, which was adopted in 2000, establishes a framework for landscape protection, planning and management in Europe and is to date the only international legal instrument of its kind. Results indicate that whilst policy innovations do not appear to be a major stimulus for academic research, studies nevertheless address a range of landscape aspects, types and scales (albeit with a slight bias towards bio-physical landscape aspects). However, geographical representativeness of research is weak and dominated by the United States and northern/western Europe, and research capacity likewise appears to be unevenly distributed. Landscape research is also limited in the extent to which it involves stakeholders or develops innovative methods for doing so, notwithstanding that this remains a key challenge for policy-makers. Results point to the potential for landscape research to address areas (topical and geographical) which have received little attention to date, as well as suggesting mutual benefits of stronger links between policy and academia.     

Societal risk assessment of major hazard installations using QuickRisk

QuickRisk is a quantitative risk assessment tool developed at the Health and Safety Laboratory for use in assessing societal risk around onshore major hazard installations to inform land-use planning decisions. It uses release scenario information, parameterised consequence models, weather data, and population data from the National Population Database (NPD).This paper describes enhancements to the NPD methodology to include workplace populations. It describes the novel numerical, graphical and geographical representations of societal risk produced by QuickRisk. F–N data are analysed in terms of scenario FN curves and Delta PLL vs. N curves, where PLL is potential loss of life. The Delta PLL curves could be useful for comparison of FN curves against FN criterion lines or other FN data on a PLL basis. Geographical representations generated from PLL density maps show: the distribution of PLL dominating release scenarios or the percentage of risk contributed by the PLL-dominant release scenario, the maximum number of fatalities associated with the worst-case event, and the associated release scenario. Geographical representations are also generated of the maximum population that would meet a PLL density criterion, and the relative population change that would match a given PLL density criterion.These novel representations of societal risk could be useful for more effective communication between stakeholders on the risk levels in the vicinity of major hazard installations.     

Dynamic Procedure for Atypical Scenarios Identification (DyPASI): A new systematic HAZID tool

The availability of a hazard identification methodology based on early warnings is a crucial factor in the identification of emerging risks. In the present study, a specific method named Dynamic Procedure for Atypical Scenarios Identification (DyPASI) was conceived as a development of bow-tie identification techniques. The main aim of the methodology is to provide a comprehensive hazard identification of the industrial process analysed, joined to a process of continuous improvement of the results of the assessment. DyPASI is a method for the continuous systematization of information from early signals of risk related to past events. The technique provides a support to the identification and assessment of atypical potential accident scenarios related to the substances, the equipment and the site considered, capturing available early warnings or risk notions. DyPASI features as a tool to support emerging risk management process, having the potentiality to contribute to an integrated approach aimed at breaking “vicious circles”, helping to trigger a gradual process of identification and assimilation of previously unrecognised atypical scenarios.     

Low Back Muscle Activity in an Automobile Seat with a Lumbar Massage System

This investigation was conducted to determine the effects of a massaging lumbar support system on low back muscle activity. The apparatus included a luxury-level automobile seat, six 10-mm diameter bipolar surface electrodes, an amplifier, an analog-to-digital conversion board, data acquisition software, and a personal computer. Six experimental conditions, each involving a variation of massage time, were considered. The dependent variable was the change in the root mean square variation of the EMG signal. One minute of lumbar massage every 5 min was found to have a beneficial effect on low back muscle activity (as compared to no massage). This may prove to be an extremely important result in the quest to combat low back pain attributable to automobile seating.