Alley Cropping of Maize with Nine Leguminous Trees

A maize-leguminous tree alley cropping system was studied on an N-deficient Vertic Haplustoll in Hawaii. Nine tree species were evaluated for green manure (GM) and intercropped maize yields. They included: Calliandra calothvrsus, Caianus caian, Cassia siamea, Gliricidia sepium, KX1— Leucaena hybrid (L. pallida X L. diversifolia), L. leucocephala. L. pallida. L. salvadorensis, and Sesbania sesban. S. sesban, G. sepium, L. pallida, and KX1 showed high potential for use as a hedge, producing between 5 and 12 dry t/ha GM with N yields between 140 and 275 kg N/ha in 4 prunings. Maize yields responded linearly to nitrogen applied as green manure. Maize yield increased 12 kg for each kg of nitrogen applied. Addition of prunings from hedge rows was able to support maize grain yield at about 1800 kg/ha for two consecutive cropping seasons, while control plot yields averaged less than 600 kg/ha. S. sesban hedges produced the most GM and yielded the highest maize yields. Maize yields reflected the amount of N applied as GM, regardless of tree species from which the N was derived. Green manure at five rates (0, 0.5x, lx, lx + 60 N from urea and 2x the amount produced by the hedge) were applied in the G. sepium and L. pallida plots. The full green manure plus urea treatment was the most efficient in increasing yields. These plots produced significantly more maize, with less total N applied, than the double G. sepium and L. pallida treatments. Significant reductions in maize yields were seen in maize rows near the hedge relative to those in the middle of the alley. Increasing the distance away from the hedge and coppicing the hedge earlier in maize growth significantly improved maize yields in the maize row closest to the trees

Universalism vs. Particularism: On the Limits of Major Power Order

Relations between major powers can be described as shifting between universalism and particularism. In periods of universalism, major powers try to work out acceptable rules of behavior among one another, whereas in periods of particularism, they emphasize special interests of special powers. The way historians see shifts in major power relations since 1816 largely follows such a classification. By comparing the policies pursued during four periods of universalism and four periods of particularism, as well as analysing what ended or initiated such periods, the limits of major power universalism can be evaluated. Particularly, the short-comings of the recent period of detente are illuminated. Also some principles for a more enduring form of universalism are suggested.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68816/2/10.1177_002234338402100304.pd

Globalization, democratization, and the Arab uprising : the international factor in MENA's failed democratization

What explains the almost negative impact of international factors on post-Uprising democratization prospects? This article compares the utility of rival “diffusionist” and neo-Gramscian political economy frames to explain this. Three international factors deter democratization. The failure of Western democracy promotion is rooted in the contradiction between the dominance of global finance capital and the norm of democratic equality; in the periphery, neo-liberalism is most compatible with hybrid regimes and, at best, “low intensity democracy.” In MENA, neo-liberalism generated a crony capitalism incompatible with democratization; while this also sparked the uprisings, these have failed to address class inequalities. Moreover at the normative level, MENA hosts the most credible counter-hegemonic ideologies; the brief peaking of democratic ideology in the region during the early uprisings soon declined amidst regional discourse wars. Non-democrats—coercive regime remnants and radical charismatic movements--were empowered by the competitive interference of rival powers in Uprising states. The collapse of many Uprising states amidst a struggle for power over the region left an environment uncongenial to democratization.PostprintPeer reviewe

Establishing a Reference Baseline for Midday Stem Water Potential in Olive and Its Use for Plant-Based Irrigation Management

12 páginas.- 7 figuras.- 4 tablas.- 55 referencias.-Midday stem water potential (SWP) is rapidly becoming adopted as a standard tool for plant-based irrigation management in many woody perennial crops. A reference or “baseline” SWP has been used in some crops (almond, prune, grape, and walnut) to account for the climatic influence of air vapor pressure deficit (VPD) on SWP under non-limiting soil moisture conditions. The baseline can be determined empirically for field trees maintained under such non-limiting conditions, but such conditions are difficult to achieve for an entire season. We present the results of an alternative survey-based approach, using a large set of SWP and VPD data collected over multiple years, from irrigation experiments in olive orchards located in multiple countries [Spain, United States (California), Italy, and Argentina]. The relation of SWP to midday VPD across the entire data set was consistent with an upper limit SWP which declined with VPD, with the upper limit being similar to that found in Prunus. A best fit linear regression estimate for this upper limit (baseline) was found by selecting the maximum R2 and minimum probability for various upper fractions of the SWP/VPD relation. In addition to being surprisingly similar to the Prunus baseline, the olive baseline was also similar (within 0.1 MPa) to a recently published mechanistic olive soil-plant-atmosphere-continuum (SPAC) model for “super high density” orchard systems. Despite similarities in the baseline, the overall physiological range of SWP exhibited by olive extends to about −8 MPa, compared to about −4 MPa for economically producing almond. This may indicate that, despite species differences in physiological responses to low water availability (drought), there may be convergent adaptations/acclimations across species to high levels of water availability. Similar to its use in other crops, the olive baseline will enable more accurate and reproducible plant-based irrigation management for both full and deficit irrigation practices, and we present tentative SWP guidelines for this purpose. Copyright © 2021 Shackel, Moriana, Marino, Corell, Pérez-López, Martin-Palomo, Caruso, Marra, Agüero Alcaras, Milliron, Rosecrance, Fulton and Searles.In addition to the authors institutions, this research was supported by the Olive Oil Commission of California and the California Olive Committee.Peer reviewe

Morality and progress:IR narratives on international revisionism and the status quo

Scholars debate the ambitions and policies of today’s ‘rising powers’ and the extent to which they are revising or upholding the international status quo. While elements of the relevant literature provide valuable insight, this article argues that the concepts of revisionism and the status quo within mainstream International Relations (IR) have always constituted deeply rooted, autobiographical narratives of a traditionally Western-dominated discipline. As ‘ordering narratives’ of morality and progress, they constrain and organize debate so that revisionism is typically conceived not merely as disruption, but as disruption from the non-West amidst a fundamentally moral Western order that represents civilizational progress. This often makes them inherently problematic and unreliable descriptors of the actors and behaviours they are designed to explain. After exploring the formations and development of these concepts throughout the IR tradition, the analysis is directed towards narratives around the contemporary ‘rise’ of China. Both scholarly and wider political narratives typically tell the story of revisionist challenges China presents to a US/Western-led status quo, promoting unduly binary divisions between the West and non-West, and tensions and suspicions in the international realm. The aim must be to develop a new language and logic that recognize the contingent, autobiographical nature of ‘revisionist’ and ‘status quo’ actors and behaviours

Causation, complexity, and the concert: the pragmatics of causal explanation in international relations

A causal explanation provides information about the causal history of whatever is being explained. However, most causal histories extend back almost infinitely and can be described in almost infinite detail. Causal explanations therefore involve choices about which elements of causal histories to pick out. These choices are pragmatic: they reflect our explanatory interests. When adjudicating between competing causal explanations, we must therefore consider not only questions of epistemic adequacy (whether we have good grounds for identifying certain factors as causes) but also questions of pragmatic adequacy (whether the aspects of the causal history picked out are salient to our explanatory interests). Recognizing that causal explanations differ pragmatically as well as epistemically is crucial for identifying what is at stake in competing explanations of the relative peacefulness of the nineteenth-century Concert system. It is also crucial for understanding how explanations of past events can inform policy prescription