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Isolipidic replacement of krabok oil by whole krabok seed reduces in vitro methanogenesis, but negatively affects fermentation
No full textThe background of the current in vitro study involves the issue of methane (CH4) production inherent to rumen fermentation. One of the dietary strategies to reduce enteric CH4 production by ruminants involves the supplementation of medium-chain fatty acids in diets. As such, oils containing high amounts of MCFA, such as coconut, palm kernel and krabok oil, are of much interest to formulate energy efficient and environmentally friendly rations for ruminants. Krabok oil (KO) reduces methanogenesis, but the appropriate inclusion level of dietary KO is unclear. We therefore investigated the dose–response relationship between krabok oil and CH4 production. In practice, the use of whole krabok seed (WKS), instead of KO, is easier, but the efficacy of WKS to inhibit methanogenesis was hitherto unknown. Thus, we also investigated whether WKS provides an alternative tool to inhibit CH4 production. The experimental substrates contained either KO, WKS, the residue of WKS after fat extraction residue (FER) or FER + KO. Appropriate amounts of WKS or its derivatives were added to a basal substrate so as to attain either a low, medium or high content of KO, that is, 37–46, 90–94 and 146–153 g/kg dry matter respectively. The experimental substrates were formulated to keep the amounts of incubated fat-free OM, crude protein, neutral detergent fibre and acid detergent fibre constant in order to avoid biased results through potential differences in fermentability between WKS and its derivatives, and the basal substrate. The latter resembled the ingredient composition of a total mixed ration commonly used in Thai dairy cows. Fully automated gas production (GP) equipment was used to measure gas- and CH4 production. Irrespective of the type of substrate (p ≥.115), both the absolute (ml/g fat-free OM) and relative (% of total GP) CH4 production was reduced at the highest inclusion level of WKS or its derivatives (p ≤.019). Total GP (ml/g fat-free OM), however, was reduced after incubation of FER, FER + KO, and WKS, but not KO, at the highest inclusion level of the respective substrates (p =.019). Volatile fatty acids were likewise affected (p ≤.001). Krabok oil can inhibit CH4 production but only when the dietary KO content is at least 9.4% (DM). Supplementation of KO in the form of WKS, however, is considered not opportune because the fat extracted residue of WKS is poorly degraded during fermentation.</p
Governance and the coastal condition : Towards new modes of observation, adaptation and integration
Full text linkThe conceptual framework of evolutionary governance theory (EGT) is deployed and extended to rethink the idea of coastal governance and the possibilities of a coastal governance better adapted to challenges of climate change and intensified use of both land and sea. ‘The coastal condition’ is analysed as a situation where particular modes of observation and coordination were possible and necessary, and those observations (and derived calculations of risk and opportunity) are valuable for the governance of both land and sea. An argument is constructed for a separate arena for coastal governance, without erasing the internal logic of pre-existing governance for land and sea. This entails that coastal governance is destined to be a place of (productive) conflict, as much as of policy integration. Policy integration will be more difficult and more important in coastal governance, as this is an arena where the effects of many land based activities and activities at sea become visible and entangled. Policy integration in coastal governance does, however, require deep knowledge of the governance path and existing forms of integration there (e.g. in planning), and it exists in an uneasy tension with the requirements of adaptive governance. This tension further contributes to the complexity and complex-prone character of coastal governance. Neither complexity nor conflict can be avoided, and coastal governance as an image of balanced decision-making is (positively) presented as a productive fiction.</p
Can We Use the Relationship Between Within-Field Elevation and NDVI as an Indicator of Drought-Stress?
No full textLarge farmers’ datasets can help shed light on agroecological processes if used in the context of hypothesis testing. Here we used an anonymized set of data from the geoplatform Akkerweb to better understand the correlation between within-field elevation and normalized differential vegetation index (NDVI, a proxy for biomass). The dataset included 3249 Dutch potato fields, for each of which the cultivar, the field polygon, the year of cultivation and the soil type (clay or sandy) was known. We hypothesize that under dry conditions such correlation is negative, meaning that the lowest portions of the field have more biomass because of water redistribution. From the data, we observed that in dry periods, such as the summer of 2018, the correlation was negative in sandy soils. Furthermore, we observed that early cultivars show a weaker correlation between NDVI and elevation than late cultivars, possibly because early cultivar escape part of the long dry summer spells. We conclude that the correlation between NDVI and elevation may be a useful indicator of drought stress, and deviations from the norm may be useful to evaluate the resistance to drought of individual cultivars
Dietary Intake Assessment: From Traditional Paper-Pencil Questionnaires to Technology-Based Tools
No full textSelf-reported methods of recall and real-time recording are the most commonly used approaches to assess dietary intake, both in research as well as the health-care setting. The traditional versions of these methods are limited by various methodological factors and burdensome for interviewees and researchers. Technology-based dietary assessment tools have the potential to improve the accuracy of the data and reduce interviewee and researcher burden. Consequently, various research groups around the globe started to explore the use of technology-based tools. This paper provides an overview of the: (1) most-commonly used and generally accepted methods to assess dietary intake; (2) errors encountered using these methods; and (3) web-based and app-based tools (i.e., Compl-eatTM, Traqq, Dutch FFQ-TOOLTM, and “Eetscore”) that have been developed by researchers of the Division of Human Nutrition and Health of Wageningen University during the past years
An intercontinental analysis of food safety culture in view of food safety governance and national values
Full text linkTaking food safety culture into account is a promising way to improve food safety performance in the food industry. Food safety culture (FS-culture) research is expanding from an organisational perspective to include characteristics of the internal and external company environment. In this study, the prevailing food safety culture in 17 food companies from four countries on three continents (Africa, Asia and Europe) was assessed in view of food safety governance and national values. The internal environment characteristics, i.e. food safety vision, food safety program and food production system vulnerability, were also assessed. Statistical analysis revealed little variation in FS-culture scores between the companies within the same country. Overall the FS-culture for Greek and Zambian companies was scored proactive, while for Chinese and Tanzanian companies an active score was achieved. Both the internal and external company environment seemed to influence the prevailing FS-culture. Cluster analysis showed that Tanzanian and Zambian companies exhibited similarities in the implementation of food safety programs, and in their national values and food safety governance as compared to Greece and China. Food safety governance was reflected in the food safety programs and supportiveness of the organisation to food safety and hygiene. All cultural dimensions were correlated with risk perceptions, with masculinity and long-term orientation also significantly correlated with the enabling conditions and attitude. Understanding how national values and food safety governance approaches differently influence food safety culture is expected to enable formulation of best approaches tailored for companies operating in countries with different company environments, to improve food safety performance.</p
Interpreting forest diversity-productivity relationships : volume values, disturbance histories and alternative inferences
Full text linkUnderstanding the relationship between stand-level tree diversity and productivity has the potential to inform the science and management of forests. History shows that plant diversity-productivity relationships are challenging to interpret—and this remains true for the study of forests using non-experimental field data. Here we highlight pitfalls regarding the analyses and interpretation of such studies. We examine three themes: 1) the nature and measurement of ecological productivity and related values; 2) the role of stand history and disturbance in explaining forest characteristics; and 3) the interpretation of any relationship. We show that volume production and true productivity are distinct, and neither is a demonstrated proxy for economic values. Many stand characteristics, including diversity, volume growth and productivity, vary intrinsically with succession and stand history. We should be characterising these relationships rather than ignoring or eliminating them. Failure to do so may lead to misleading conclusions. To illustrate, we examine the study which prompted our concerns —Liang et al. (Science 354:aaf8957, 2016)— which developed a sophisticated global analysis to infer a worldwide positive effect of biodiversity (tree species richness) on “forest productivity” (stand level wood volume production). Existing data should be able to address many of our concerns. Critical evaluations will improve understanding.</p
Genotypic variation in source and sink traits affects the response of photosynthesis and growth to elevated atmospheric CO<sub>2</sub>
No full textThis study aimed to understand the response of photosynthesis and growth to e-CO2 conditions (800 vs. 400 μmol mol−1) of rice genotypes differing in source–sink relationships. A proxy trait called local C source–sink ratio was defined as the ratio of flag leaf area to the number of spikelets on the corresponding panicle, and five genotypes differing in this ratio were grown in a controlled greenhouse. Differential CO2 resources were applied either during the 2 weeks following heading (EXP1) or during the whole growth cycle (EXP2). Under e-CO2, low source–sink ratio cultivars (LSS) had greater gains in photosynthesis, and they accumulated less nonstructural carbohydrate in the flag leaf than high source–sink ratio cultivars (HSS). In EXP2, grain yield and biomass gain was also greater in LSS probably caused by their strong sink. Photosynthetic capacity response to e-CO2 was negatively correlated across genotypes with local C source–sink ratio, a trait highly conserved across environments. HSS were sink-limited under e-CO2, probably associated with low triose phosphate utilization (TPU) capacity. We suggest that the local C source–sink ratio is a potential target for selecting more CO2-responsive cultivars, pending validation for a broader genotypic spectrum and for field conditions.</p
Sustainable intensification and diversification options with grain legumes for smallholder farming systems in the Guinea savanna of Ghana
Full text linkFood security is a critical issue in the Guinea savanna of Ghana where about 60% of the rural population, mostly smallholder farmers are food insecure. Food insecurity results from poor crop yields due to low soil fertility compounded by erratic unimodal rainfall and the inability of households to purchase required supplemental food. Rapid population growth means that the numbers of food insecure people are likely to increase, necessitating sustainable intensification and diversification to increase crop production per unit area of land. This thesis focused on testing spatial and temporal intensification and diversification options suitable for the variable biophysical and socio-economic conditions of smallholder farming systems in the Guinea savanna to increase productivity, mitigate the risk of crop failure, and thus to increase food self-sufficiency. One site in the southern Guinea savanna and one in the northern Guinea savanna were selected which differed in biophysical and socio-economic resources. In each site, field experiments were conducted on three fields differing in soil fertility (fertile, medium fertile, poorly fertile) to quantify: N2-fixation and N contribution to soil fertility by grain legumes in sole and intercropping; impact of replacement intercropping on increasing resource use efficiency and crop productivity; and productivity of relay (additive) intercropping and rotation of grain legumes with maize. Scenario analysis was performed with data from the N2Africa Ghana project supplemented with data from the on-farm experiments and literature to test the impacts of intensification and diversification options on household food self-sufficiency. Sole legumes fixed larger amounts of N2 than under intercropping. The soil N balance was generally positive and similar between intercrops and sole crops suggesting that both systems could be sustainable intensification and diversification options. Poor fields stimulated grain legumes to rely on atmospheric N2 for growth leading to more positive soil N balances than in fertile fields. Consequently, legumes in poor fields were more competitive with maize and led to greater intercrop yield advantage than in fertile fields. Across all fields and sites, intercropping enhanced the efficiency in resource use resulting in a 26% to 46% yield advantage over sole cropping. Intercrops were more efficient and productive in the drier northern Guinea savanna than in the wetter southern Guinea savanna. Yet the absolute larger grain yields achieved in fertile fields and in the southern Guinea savanna with more favourable soil fertility and rainfall resulted in greater net benefits. This suggests that intercropping is beneficial both in poorly fertile and fertile fields though the benefits take different dimensions. Legume-cereal rotation was superior in increasing the yield of maize without N fertiliser ranging from 0.38 t ha-1 in NGS to 1.01 t ha-1 in SGS due to residual N and non-N benefits compared with continuous maize cropping. Sowing cowpea first and relaying maize decreased maize grain yield substantially from 0.29 t ha-1 (14%) in SGS to 0.82 t ha-1 (83%) in NGS, representing 14% and 83% grain yield reductions relative to maize sown at the beginning of the season. These grain yield reductions were due to inadequate rainfall received by the relay maize. When maize was sown from the onset of the season and the cowpea relayed, the cowpea grain yield reduction was relatively smaller compared with that of maize. Such cowpea grain yield decline was similar between the SGS and NGS and ranged from 28% (0.18 t ha-1) to 47% (0.26 t ha-1) relative to the cowpea sown from the onset of the season. The cumulative grain yield of this relay system over two seasons was similar to that of the legume-cereal rotations even with cowpea failing to yield in the first season. The scenario analysis revealed a high incidence of food insufficiency among smallholder farm households in the Guinea savanna of Ghana. This ranged from 56% in the Northern region with relatively favourable rainfall, soil fertility and larger land area cropped per farm to 45% in the Upper East and Upper West regions with comparatively less rainfall, poor soils and smaller land area cropped. In addition, 21% of households in the Northern region and 37% in the Upper East and Upper West regions could only survive on their own food production for six months or less. However, the scenario analysis suggested that through intensification and diversification with grain legumes, the proportion of food self-sufficient households in the Guinea savanna could increase by 25 – 43% and those self-sufficient for a maximum of half a year decreased to 3 – 15%. Households could also generate substantial marketable surpluses to earn income. However, the total size of land cropped by a farm household matters, and improved access to markets and credit are needed to acquire the relevant inputs. Also, multi-year analysis using modelling would be relevant in providing insights on long-term nutrient balances, especially of N and soil organic matter to understand the long-term sustainability of the various options
Evaluation of Terrestrial Laser Scanner and Structure from Motion photogrammetry techniques for quantifying soil surface roughness parameters over agricultural soils
No full textThe surface roughness of agricultural soils is mainly related to the type of tillage performed, typically consisting of oriented and random components. Traditionally, soil surface roughness (SSR) characterization has been difficult due to its high spatial variability and the sensitivity of roughness parameters to the characteristics of the instruments, including its measurement scale. Recent advances in surveying have greatly improved the spatial resolution, extent, and availability of surface elevation datasets. However, it is still unknown how new roughness measurements relates with the conventional roughness measurements such as 2D profiles acquired by laser profilometers. The objective of this study was to evaluate the suitability of Terrestrial Laser Scanner (TLS) and Structure from Motion (SfM) photogrammetry techniques for quantifying SSR over different agricultural soils. With this aim, an experiment was carried out in three plots (5 × 5 m) representing different roughness conditions, where TLS and SfM photogrammetry measurements were co‐registered with 2D profiles obtained using a laser profilometer. Differences between new and conventional roughness measurement techniques were evaluated visually and quantitatively using regression analysis and comparing the values of six different roughness parameters. TLS and SfM photogrammetry measurements were further compared by evaluating multi‐directional roughness parameters and analyzing corresponding Digital Elevation Models. The results obtained demonstrate the ability of both TLS and SfM photogrammetry techniques to measure 3D SSR over agricultural soils. However, profiles obtained with both techniques (especially SfM photogrammetry) showed a loss of high‐frequency elevation information that affected the values of some parameters (e.g. initial slope of the autocorrelation function, peak frequency and tortuosity). Nevertheless, both TLS and SfM photogrammetry provide a massive amount of 3D information that enables a detailed analysis of surface roughness, which is relevant for multiple applications, such as those focused in hydrological and soil erosion processes and microwave scattering
Post-fire management treatment effects on soil properties and burned area restoration in a wildland-urban interface, Haifa Fire case study
No full textIn November 2016, the urban dry streams (wadis) of the city of Haifa in Northern Israel were on fire. However, it was not just the fire that was threatening urban areas. Post-fire precipitation could turn into urban floods, further aggravating the fire damages. Several months after the fire a considerable restoration effort was initiated to restore the burned areas and mitigate future events. For urban forests the rehabilitation strategy was planned and implemented according to the topographic structure of the burned site and anticipated soil erosion. Accordingly, various post-fire management techniques were used: salvage-logging, afforestation, log erosion barriers and coconut fibre-webs. This study aimed to look at the effects of these methods on soil properties, namely, gravimetrical soil moisture, soil organic matter content, pH, electrical conductivity, hydraulic conductivity and soil water repellency. Results indicate that the control (burned, non-managed) site was the highest in soil moisture, organic matter and electrical conductivity compared to all other sites, however, the existence of ash cover made the response to precipitation unpredictable. The hydraulic conductivity (K) of the black ash (24.1 ± 8.6 mm/h), the white ash (19.0 ± 10.7 mm/h) and the disturbed (mixed) ash (11.7 ± 3.7 mm/h) were significantly higher than the underlying soil (3.3 ± 0.7 mm/h). As a result of these differences in K value, precipitation only infiltrates through the ash layers and then flows along the interface of the ash and the soil, triggering soil erosion. Most of the sites that were salvage logged showed signs of erosion. The log barriers were only effective for downstream areas. The afforestation could help to homogenise the soil, but the vegetation cover would be less dense and stable than after natural reforestation. Furthermore, the coconut fibre webs helped to improve the soil water retention and decreased the direct impact of rainfall.</p