What motivates farmers to participate in the Nova Scotia environmental farm plan program? Evidence and environmental policy implications

Program stakeholders are interested in better understanding farmers' experience, and factors that affect farmer participation in the relatively new Environmental Farm Plan (EFP) program, implemented in several provinces in Canada. To increase relevance of the research findings to EFP program administrators and policy makers, the research methods emphasised determining whether relationships exist among program-related variables, and how such relationships affect farmers' decision choices and behaviour. Traditional farmer and farm attributes that have contrasting effects in agricultural innovation adoption and conservation management (namely age, and formal education completed), were not associated with EFP program participation. Farm income, years of farming experience, and type of agribusiness managed were associated with participation in the Nova Scotia EFP program. Although program participants tended to have higher incomes, overall, non-financial considerations dominated monetary considerations in Nova Scotia farmers' reasons for participating in the Nova Scotia EFP. Helping to publicize positive farm stewardship practices was reported as the most important reason for participating in the EFP scheme, followed by its use to help improve relationships with non-farming neighbours, and to comply with government environmental regulations. In contrast, and somewhat a surprising finding, minimizing potential farm environmental risk, program administrators' raison d'être for promoting the NS EFP, was ranked the lowest, with no respondent rating that as a "very important" or "extremely important" reason for participating in the EFP program.     

Use of fuzzy logic models for prediction of taste and odor compounds in algal bloom-affected inland water bodies

Mechanistic modeling of how algal species produce metabolites (e.g., taste and odor compounds geosmin and 2-methyl isoborneol (2-MIB)) as a biological response is currently not well understood. However, water managers and water utilities using these reservoirs often need methods for predicting metabolite production, so that appropriate water treatment procedures can be implemented. In this research, a heuristic approach using Adaptive Network-based Fuzzy Inference System (ANFIS) was developed to determine the underlying nonlinear and uncertain quantitative relationship between observed cyanobacterial metabolites (2-MIB and geosmin), various algal species, and physical and chemical variables. The model is proposed to be used in conjunction with numerical water quality models that can predict spatial–temporal distribution of flows, velocities, water quality parameters, and algal functional groups. The coupling of the proposed metabolite model with the numerical water quality models would assist various utilities which use mechanistic water quality models to also be able to predict distribution of taste and odor metabolites, especially when monitoring of metabolites is limited. The proposed metabolite model was developed and tested for the Eagle Creek Reservoir in Indiana (USA) using observations over a 3-year period (2008–2010). Results show that the developed models performed well for geosmin (R ²?=?0.83 for all training data and R ²?=?0.78 for validation of all 10 data points in the validation dataset) and reasonably well for the 2-MIB (R ²?=?0.82 for all training data and R ²?=?0.70 for 7 out of 10 data points in the validation dataset).     

Beehive fences as a multidimensional conflict‐mitigation tool for farmers coexisting with elephants

Increasing habitat fragmentation and human population growth in Africa has resulted in an escalation in human–elephant conflict between small‐scale farmers and free‐ranging African elephants (Loxodonta Africana). In 2012 Kenya Wildlife Service (KWS) implemented the national 10‐year Conservation and Management Strategy for the Elephant in Kenya, which includes an action aimed at testing whether beehive fences can be used to mitigate human–elephant conflict. From 2012 to 2015, we field‐tested the efficacy of beehive fences to protect 10 0.4‐ha farms next to Tsavo East National Park from elephants. We hung a series of beehives every 10 m around the boundary of each farm plot. The hives were linked with strong wire. After an initial pilot test with 2 farms, the remaining 8 of 10 beehive fences also contained 2‐dimensional dummy hives between real beehives to help reduce the cost of the fence. Each trial plot had a neighboring control plot of the same size within the same farm. Of the 131 beehives deployed 88% were occupied at least once during the 3.5‐year trial. Two hundred and fifty‐three elephants, predominantly 20–45 years old entered the community farming area, typically during the crop‐ ripening season. Eighty percent of the elephants that approached the trial farms were kept out of the areas protected by the beehive fences, and elephants that broke a fence were in smaller than average groups. Beehive fences not only kept large groups of elephants from invading the farmland plots but the farmers also benefited socially and financially from the sale of 228 kg of elephant‐friendly honey. As news of the success of the trial spread, a further 12 farmers requested to join the project, bringing the number of beehive fence protected farms to 22 and beehives to 297. This demonstrates positive adoption of beehive fences as a community mitigation tool. Understanding the response of elephants to the beehive fences, the seasonality of crop raiding and fence breaking, and the willingness of the community to engage with the mitigation method will help contribute to future management strategies for this high human–elephant conflict hotspot and other similar areas in Kenya.     

Optimizing process parameters of palm oil bleaching on locally prepared animal bone–based activated carbon using response surface methodology

Adsorptive bleaching potentials of activated animal bone on palm oil was investigated. Palm oil was obtained locally from the mesocarp of oil palm fruits. The obtained palm oil was degummed, neutralized, and subjected to proximate analysis before bleaching. The animal bone–based activated carbon used as a bleaching material was locally prepared by cleaning, drying, carbonization, and chemical activation process. The prepared activated carbon (CBAC) was characterized using Fourier transform infrared, scanning electron microscopy, Braummer–Emmett–Teller, and x‐ray diffraction (XRD) methods. Bleaching of the prepared palm oil on CBAC was done at different process conditions. The characterization results of BET analysis show that CBAC has a surface area of 593.270 m²/g, micropore surface area 595.56 m²/g, micropore volume 0.212 cm³/g, Langmuir surface area 1.38e+04 m²/g, and adsorption energy 3.998 KJ/mol. XRD analysis indicates gypsum as the dominant mineral in the activated carbon sample. The CBAC efficiency of 75.14% was obtained for time/temperature interactions at 50 min/120°C while at 25 g/50 min dosage/time interactions an efficiency of 75.17% was obtained.     

Ecotoxicological effects of an aged TiO2 nanocomposite measured as apoptosis in the anecic earthworm Lumbricus terrestris after exposure through water, food and soil

Titanium dioxide nanoparticles seem to have a low toxicity to terrestrial organisms, though few studies are published in this area. TiO(2) used in sunscreens are nanocomposites where TiO(2) has been coated with magnesium, silica or alumina, as well as amphiphilic organics like polydimethyl siloxane (PDMS), and these coatings are modified by ageing. We assessed the ecotoxicity and propensity for bioaccumulation of an aged TiO(2) nanocomposite used in sunscreen cosmetics, and its potential effect on the frequency of apoptosis in different earthworm tissues. The earthworm Lumbricus terrestris was exposed to the TiO(2) nanocomposite for 7 days in water or 2-8 weeks in soil with the nanocomposite mixed either into food or soil at concentrations ranging from 0 to 100 mg kg(-1). Apoptosis was then measured by immunohistochemistry and Ti localized by XRF microscopy. Results showed no mortality, but an enhanced apoptotic frequency which was higher in the cuticule, intestinal epithelium and chloragogenous tissue than in the longitudinal and circular musculature. TiO(2) nanoparticles did not seem to cross the intestinal epithelium/chloragogenous matrix barrier to enter the coelomic liquid, or the cuticule barrier to reach the muscular layers. No bioaccumulation of TiO(2) nanocomposites could thus be observed.     

Modeling biogeochemical processes of phosphorus for global food supply

Harvests of crops, their trade and consumption, soil erosion, fertilization and recycling of organic waste generate fluxes of phosphorus in and out of the soil that continuously change the worldwide spatial distribution of total phosphorus in arable soils. Furthermore, due to variability in the properties of the virgin soils and the different histories of agricultural practices, on a planetary scale, the distribution of total soil phosphorus is very heterogeneous. There are two key relationships that determine how this distribution and its change over time affect crop yields. One is the relationship between total soil phosphorus and bioavailable soil phosphorus and the second is the relationship between bioavailable soil phosphorus and yields. Both of these depend on environmental variables such as soil properties and climate. We propose a model in which these relationships are described probabilistically and integrated with the dynamic feedbacks of P cycling in the human ecosystem. The model we propose is a first step towards evaluating the large-scale effects of different nutrient management scenarios. One application of particular interest is to evaluate the vulnerability of different regions to an increased scarcity in P mineral fertilizers. Another is to evaluate different regions’ deficiency in total soil phosphorus compared with the level at which they could sustain their maximum potential yield without external mineral inputs of phosphorus but solely by recycling organic matter to close the nutrient cycle.     

Impact of salt-marsh management on fish nursery function in the bay of Aiguillon (French Atlantic coast), with a focus on European sea bass diet

The Bay of Aiguillon is a national French Nature Reserve of great importance for birds. Recently, the managers of the Reserve (ONCFS-LPO) paid attention to the influence of saltmarshes management on the nursery function for fish feeding in creeks at high tide. A study carried out from March to July 2012 aimed to evaluate the use of saltmarshes by fish juvenile fraction according to the mowing intensity in salt marshes surrounding creeks: ceased, irregular or annual mowing. This community approach was completed by a focus on the European sea bass Dicentrarchus labrax individual diet, vacuity index and growth, and the biomass of a main potential prey (the amphipod Orchestia gammarella). Whatever the mowing intensity, the juvenile fraction was very high for the main species, which were the grey mullet Liza ramada, the European sea bass, undetermined clupeid and the European flounder Platichthys flesus. Adult and subadult for these species were anecdotic or totally absent. Despite very different biomasses of amphipods between mown and natural sites, vacuity index, prey composition and their relative abundance in the diet of European sea bass juveniles were little different, contrary to their hypothetical growth (i.e. when assuming site fidelity), which appeared higher in non-mown site. The low distance between sampling sites could allow fish exchange over time between optimal and suboptimal creeks to feed on, as a hypothesis to explain such results. Because mowing was subsidized by European Union (EU) to favour open habitats for geese and maintain an economic activity, indirect impacts on nursery for fish called into question the appropriateness of such agro-environmental measure on natural habitats, and related fish nursery function.     

Measurement of mass exchange processes and coefficients in a simplified open-channel lateral cavity connected to a main stream

Lateral cavities are major storage zones in riverine environments for which the mass exchanges with the main stream strongly impact the characteristics of the habitat in these dead zones. An experimental work is presented here with a controlled main stream and a connected open-channel lateral cavity to assess the processes responsible for these exchanges and to quantify the exchange capacities. In a first step, the measurements of passive scalar transport allow us to identify the physical processes involved in the exchange of mass from the main stream and its spreading within the cavity. In a second step, the quantitative mass exchange coefficient, representative of the exchange capacity, is measured for 28 flow and cavity configurations. The sensibility analysis to the governing parameters proposed by the dimensional analysis then reveals that changing the geometric aspect ratio of the cavity does not affect the exchange coefficient while increasing the normalized water depth or decreasing the Reynolds number of the main stream tend to increase this coefficient. Indeed, these parameters modify both the growth rate of the mixing layer width at the interface and the amplitude of the alternating transverse velocity across the interface, thus affecting the exchange capacities from the main stream to the cavity.     

Effect of Liquefied Petroleum Gas on Ozone Formation in Guadalajara and Mexico City

Abstract

Leakages of liquefied petroleum gas (LPG) are suspected to contribute greatly to ozone (O₃) formation in Mexico City. We tested such a hypothesis by outdoor captive-air irradiation (CAI) experiments in the two largest Mexican metropolitan areas: Guadalajara (GMA) in 1997 and Mexico City (MCMA) in 2000. O₃ was monitored in each city for 20 days (8:00 a.m.–6:00 p.m.) in smog chambers containing unaltered morning air or morning air enriched with either commercial LPG or LPG synthetic mixture 60/40 (propane and butane). Tested additions of both components were 35% (by volume) in GMA and 60% (by volume) in MCMA. The addition effects on O₃ (max) were compared with effects from diluting LPG components or total nonmethane hydrocarbons (tNMHCs) by 50%. Diluting tNMHCs had the greatest absolute effect at both cities: it lowered O₃ (max) by 24% in GMA and 55% in MCMA. Adding commercial LPG increased O₃ (max) by 6% in GMA and 28% in MCMA; whereas adding LPG synthetic mixture 60/40 caused a similar increase in O₃ (max), 4 and 21% in GMA and MCMA, respectively. Compared with dilution of tNMHCs, dilution of LPG-associated compounds had a smaller decreasing effect on O₃ (max), only 4% in GMA and 15% in MCMA. These results show that commercial LPG and LPG synthetic mixture 60/40 affect O₃ formation to a lesser extent than estimated previously.