‘Water war’ in the Mekong Basin?

The Mekong River system provides a crucial source of natural resources for riparian nations. However, the increasingly rapid pace of hydro‐development in the Mekong Basin is threatening the integrity of the river system, posing a real concern for Lower Basin states, which are particularly dependent on the basin. This scenario has led to warnings of armed conflict, or even ‘water war’, between riparian states. Certainly, the expanding scale of hydro‐development can be expected to continue increasing interstate tensions in the Mekong region; but are these tensions really likely to escalate to armed conflict? This paper explores this question by drawing on the water and conflict theory of Aaron Wolf. Ultimately, this paper concludes that interstate tensions over Mekong hydro‐development are unlikely to generate armed conflict. This is in part due to the strategic impracticality of such a conflict as well as the presence of a river basin management institution. Most compellingly, though, armed conflict is unlikely because the economic imperative shared by Mekong states is better served by cooperation – or at least non‐interference – than conflict, over regional hydro‐development. In closing, the paper urges that the study of water and conflict in the Mekong Basin be refocused at the intrastate level.     

From ‘wannabe’ Silicon Valley to global back office? Examining the socio‐spatial consequences of technopole planning practices in Malaysia

Cyberjaya is one of a long line of aspiring science and technology parks in the Asia‐Pacific region that have attempted to create a successful technopole, and in doing so become the ‘Silicon Valley of Asia’. The paper attends to the place‐making strategies through which Cyberjaya was positioned as a new ‘global hub’ for information communication technology and multimedia industries, framed as an extremely ‘sticky place’ (Markusen, 1996). That is, a place within a global economic system where local skills, infrastructure and capital attracts and makes research and development and corporate headquarters reluctant to leave. The paper considers that despite considerable infrastructural investment and state‐led urban boosterism to ‘sell’ Cyberjaya to prospective investors, more than 10 years after its completion in 1999 the development has become little more than a zone of disconnected business process outsourcing industries comprising low value‐added outsourcing activities.     

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.     

Responses of soil properties,root growth and crop yield to tillage and crop residue management in a wheat–maize cropping system on the North China Plain

Crop residue removal and subsoil compaction are limiting to yield improvement in the North China Plain (NCP). We conducted a field study composed of six consecutive crop growing seasons from 2010 to 2013 in Henan province, China, to determine responses of soil properties, crop root distribution and crop yield to tillage and residue management in a wheat–maize cropping system under irrigated conditions. Tillage practices comprised mouldboard ploughing (MP) to a depth of 15-cm, deep mouldboard ploughing (DMP) to a depth of 30-cm, and chisel ploughing (CP) to a depth of 30-cm. Crop residue management included crop residue retained (CRRet) and crop residue removed (CRRem). The results indicated that yields in DMP and CP increased by 6.0% and 7.3% for wheat and by 8.7% and 9.0% for maize, respectively, relative to MP. The CRRet treatment also increased wheat yield by 6.7% and maize yield by 5.0%. The yield increases under DMP and CP were related to reduced bulk density and soil penetration resistance, increased soil water content, improved total N distribution and improved root density (0–60-cm). Compared with MP, the root mass density under DMP and CP were increased by 43.4% and 42.0% for wheat and by 40.6% and 39.4% for maize, respectively. The yield increases under CRRet were also related to increased soil water content, reduced penetration resistance and increased N status (0–40-cm). Overall, for DMP + CRRet and CP + CRRet, a more favorable soil environment alongside greater root mass density and suitable spatial distribution resulted in higher grain yields of wheat and maize. Thus, compared with conventional shallow tillage practice, DMP or CP with residue application could improve soil quality and agricultural productivity under irrigated areas with loam soil in the NCP.     

Can additional N fertiliser ameliorate the elevated CO2‐induced depression in grain and tissue N concentrations of wheat on a high soil N background?

Elevated CO₂ stimulates crop yields but leads to lower tissue and grain nitrogen concentrations [N], raising concerns about grain quality in cereals. To test whether N fertiliser application above optimum growth requirements can alleviate the decline in tissue [N], wheat was grown in a Free Air CO₂ Enrichment facility in a low‐rainfall cropping system on high soil N. Crops were grown with and without addition of 50–60 kg N/ha in 12 growing environments created by supplemental irrigation and two sowing dates over 3 years. Elevated CO₂ increased yield and biomass (on average by 25%) and decreased biomass [N] (3%–9%) and grain [N] (5%). Nitrogen uptake was greater (20%) in crops grown under elevated CO₂. Additional N supply had no effect on yield and biomass, confirming high soil N. Small increases in [N] with N addition were insufficient to offset declines in grain [N] under elevated CO₂. Instead, N application increased the [N] in straw and decreased N harvest index. The results suggest that conventional addition of N does not mitigate grain [N] depression under elevated CO₂, and lend support to hypotheses that link decreases in crop [N] with biochemical limitations rather than N supply.