No-tillage and direct seeding for super hybrid rice production in rice–oilseed rape cropping system

No-tillage and direct seeding (NTDS) is an effective crop production method for reducing production costs and soil conservation. In order to understand performance of super hybrid rice under NTDS in rice–oilseed rape cropping system, a researcher-managed trail (2004–2010) and an on-farm research (2002–2005) were conducted to compare different tillage (conventional tillage or no-tillage) and rice establishment methods (transplanting or direct seeding) in super hybrid rice–oilseed rape cropping system. Under researcher-managed condition, grain yields of super hybrid rice under NTDS and conventional tillage and transplanting (CTTP) were equal. Compared with under CTTP, super hybrid rice under NTDS was characterized by more panicle number per m² but less spikelet number per panicle, and lower aboveground biomass production before heading but higher aboveground biomass accumulated during heading to maturity. Higher maximum tiller number per m² and lower spikelet production efficiency were responsible for the more panicle number per m² and less spikelet number per panicle under NTDS, respectively. Under farmer-managed condition, super hybrid rice under NTDS had more panicle number m² than under CTTP, which resulted in higher grain yield. Labor input under NTDS was lower than that under CTTP. Moreover, adoption of NTDS for super hybrid rice production had no significant impacts on seed yield and yield components of oilseed rape in rice–oilseed rape cropping system. Our study showed that CTTP could be replaced with NTDS to maintain yield and save labor for super hybrid rice production in rice–oilseed rape cropping system.     

Can mineral and organic fertilization help sequestrate carbon dioxide in cropland?

The soil organic matter content represents a huge reservoir of plant nutrients and an effective safeguard against pollution; beside it can sequestrate atmospheric CO₂. Since 1966 up to now in the Southeast Po valley (Italy), the soil organic C (SOC) and total N (TN) dynamics in the 0–0.40 m soil layer under a maize–wheat rainfed rotation are studied as influenced by organic and mineral N fertilizations. Every year in the same plots cattle manure, cattle slurry, and crop residues (i.e. wheat straw and maize stalk) are ploughed under to 0.40 m depth at a same dry matter rate (6.0 and 7.5 t DM ha⁻¹ year⁻¹ after wheat and maize, respectively) and are compared to an unamended control. Each plot is splitted to receive four rates of mineral fertilizer (0–100–200–300 kg N ha⁻¹). In the whole experiment, in 2000 SOC concentration was lower than in 1966 (6.77 and 7.72 g kg⁻¹, respectively), likely for the deeper tillage that diluted SOC and favoured mineralization in deeper soil layer. From 1972 to 2000 SOC stock did not change in the control and N fertilized plots, while it increased at mean rates of 0.16, 0.18, and 0.26 t ha⁻¹ year⁻¹ with the incorporation of residues, slurry and manure, corresponding to sequestration efficiencies of 3.7, 3.8 and 8.1% of added C with the various materials. TN followed the same SOC dynamic, demonstrating how it depends on the soil organic matter. Manure thus confirmed its efficacy in increasing both SOC content and soil fertility on the long-term. In developed countries, however, this material has become scarcely available; slurry management is expensive and implies high environmental risks. Moreover, in a C balance at a farm (or regional) scale, the CO₂ lost during manure and slurry stocking should be considered. For these reasons, the incorporation of cereal residues, even if only a little of their C content was found capable of soil accumulation, appears the best way to obtain a significant CO₂ sequestration in developed countries. Our long-term experiment clearly shows how difficult it is to modify SOC content. Moreover, because climate and soil type can greatly influence SOC dynamic, to increase CO₂ sequestration in cropland, it is important to optimize the fertilization within an agricultural management that includes all the agronomic practices (e.g. tillage, water management, cover crops, etc.) favouring the organic matter build up in the soil.     

Examining talent attraction and retention in small and medium-sized cities: Where do universities fit in?

As universities have become more integrated into their communities and regions, their host cities have become locations of choice for the highly educated facilitating increased innovation and productivity rates in several locales. Recent transitions toward knowledge-driven economies have also intensified growing geographic divides along the lines of education and raised concerns about the possibility of brain drain in a growing number of cities/regions. This study examines the changing geography of highly educated individuals (2000–2017) with a focus on small and medium-sized U.S. metropolitan areas with and without research universities. Results indicate the continuing trend of divergence among regions, but research universities are found to complement (the lack of) talent agglomeration and generate spatial spillovers beyond the county boundaries.     

Resettling,disconnecting or displacing? Attending to local sociality,culture and history in disaster settings

In many disaster settings, top‐down responses emphasise ‘expert‐led’ solutions that often involve relocating disaster‐affected communities. While the intention might be to move people from harm's way and facilitate recovery, failure to attend to local pre‐disaster circumstances as well as the interplay between power, resilience and vulnerability within and around affected communities often sees resettlement reconfigure as displacement or disconnection. This oversight may even usher in a new phase of dispossession and disadvantage for marginalised groups (particularly in colonial settings). This paper explores experiences in Australia, Japan and Taiwan to reflect on what issues of local sociality, local culture and local resilience need to be attended to in framing ‘better’ disaster responses.     

Species strategy and N fluxes in grassland soil: A question of root litter quality or rhizosphere activity?

A clear understanding of the feedback between plant communities and soil nutrient cycles is necessary to predict the dynamics of grassland ecosystems. Nitrogen fluxes may depend on specific functional plant traits in relation to dead and living roots, which determine a litter and a rhizosphere effect of the plant community. Two species of nutrient-rich grasslands that demonstrate either a more conservative (Dactylis) or more competitive strategy (Lolium) for nitrogen were grown at a non-optimal level of N availability and at optimal water, P and K supply. In a factorial experiment, monocultures of both species were sown on soil monoliths containing the intact dead root litter system of either species. The N fluxes were measured for two years in these microcosms.The presence of a growing stand increased the N mineralisation rate of the root litter. Both the type of root litter and that of the rhizosphere significantly affected the N fluxes. A greater N harvest was recorded in the Dactylis stand and on the Lolium litter; while greater N loss by leaching occurred under the Lolium stand and from the Lolium litter. Lolium induced a greater N turnover in SOM, while Dactylis caused a faster decay rate of litter N. Dactylis favoured the “short” N cycle between stand and root litter, while Lolium favoured the “complete” N cycle between stand and SOM. The chemical composition of the root litter was similar, but the species effects on the N cycles could be accounted for by differences in morphological root traits. A set of functional root processes is proposed that differentiates species strategies towards the nitrogen cycle. Dynamic consequences for a mixture of the two species are discussed.     

NIMBY or NIABY? Who defines a policy problem and why: Analysis of framing in radioactive waste disposal facility placement in South Korea

This paper applies discourse analysis to policies surrounding the siting of radioactive waste disposal facilities in South Korea. We question the premises of previous studies that define the radioactive waste disposal facilities decision outcomes in Korea as ‘repeated failures’. Instead, we suggest that underlying ideas and value systems surrounding the policy problem differ between supporting and opposing parties. In particular, our focus is on the ‘framing’ strategies manifest in policy discourse. Our analysis of newspaper articles shows that participants define and frame the policy issue in distinctive ways. Framing strategies include selective attention to, and naming of, the policy issues in the processes of frame articulation, amplification, extension and transformation. Overall, our analysis shows that framing analysis is a useful tool for understanding the policy decision‐making process from a different perspective than traditional policy analysis.     

Are Homes Near Water Bodies and Wetlands Worth More or Less? An Analysis of Housing Prices in One Connecticut Town

Proximity to wetlands and water bodies can be considered an amenity (for open space and recreation value), as well as a possible nuisance (with the potential for flooding or development restrictions), although the overall effect may be different depending on location. Studies of the impacts of wetlands and water on housing prices can also be prone to spatial autocorrelation problems arising from omitted unobservables. McMillen and Redfearn explain that locally weighted regressions (LWRs) can address spatial autocorrelation. In addition to ordinary least squares (OLS), we use LWR to control for spatial effects and analyze how proximity to water bodies and wetland areas impact real sales prices of homes in one Connecticut town in 2000–2009. With OLS regressions, proximity to wetland areas and water bodies are insignificant determinants of the real sale price of homes. When we control for spatial effects with a nonparametric (i.e., LWR) approach, the significance of the water variable is different than from OLS—while greater distance from wetlands leads to an insignificant relationship with housing price, the water distance effect becomes negative and significant. These results imply that incorporating potential spatial heterogeneity in the data is crucial for accurately estimating the direction, magnitudes, and statistical significance of the relationships between environmental variables and housing prices.     

Gateways or backdoors to development? Filtering mechanisms and territorial embeddedness in the Chilean copper GPN’s urban system

This paper analyses the role played by different urban nodes in the Chilean copper mining Global Production Network (GPN), and how filtering mechanisms act in favour of the capital city, limiting the territorial embeddedness of extractive industry in resource peripheries. In doing so, we make three contributions to the literature. First, in addition to observing gateway cities (those connecting the mining hinterlands to the global economy), we propose an intermediate category in urban hierarchies which we label the “backdoor city” (those that can perform one or more functions of a gateway city but lack chances for value capture and sustainable development outcomes). Second, we analyse the filtering mechanisms that work to the detriment of resources peripheries. Third, we analyse how these mechanisms reduce the territorial embeddedness of mining activity across the Chilean urban hierarchy. Our main results show that the capital city of Santiago stands out as the only gateway city in the country, and Antofagasta acts as a backdoor city for the Chilean resource peripheries where the extractive activity is weakly embedded, limiting their development opportunities.     

How do grassroot NGOs in rural Myanmar express their visions for the food system? Food security and food sovereignty as entangled narratives within NGO struggles and strategies

Recent research has promoted the idea that political struggles over food systems can be understood through the concepts of food security (the right to access food) and food sovereignty (the right to exercise control over food systems). These concepts emphasise different political priorities in the social relations of food: for the former, the promotion of decent work and the strengthening of the social safety net to enhance people's abilities to put food on their plates; for the latter, the defence of land, water and resource rights, to underpin capabilities for food own‐provisioning. The question we pose in this paper is how these priorities are articulated by grassroots non‐government organisations working at the frontline of global food poverty? Interviews with 22 representatives of food‐related non‐government organisations in Myanmar were used to elicit narratives about how they understood their challenges. The paper finds that narratives did not cohere exclusively to either the food security or food sovereignty concept, but blended ideas associated with the political priorities of both in complex and contradictory ways. These insights lend important firsthand evidence to the argument that supports a multi‐dimensional framing of the politics of food that is inclusive of the diverse struggles highlighted by food security and food sovereignty concepts.