Agronomic and Economic Performance Characteristics of Conventional and Low-External-Input Cropping Systems in the Central Corn Belt

We conducted a 9-ha field experiment near Boone, IA, to test the hypothesis that yield, weed suppression, and profit characteristics of low-external-input (LEI) cropping systems can match or exceed those of conventional systems. Over a 4-yr period, we compared a conventionally managed 2-yr rotation system {corn (Zea mays L.)/soybean [Glycine max (L.) Merr.]} with two LEI systems: a 3-yr corn/soybean/small grain + red clover (Trifolium pratense L.) rotation, and a 4-yr corn/soybean/small grain + alfalfa (Medicago sativa L.)/alfalfa rotation. Synthetic N fertilizer use was 59 and 74% lower in the 3- and 4-yr systems, respectively, than in the 2-yr system; similarly, herbicide use was reduced 76 and 82% in the 3- and 4-yr systems. Corn and soybean yields were as high or higher in the LEI systems as in the conventional system, and weed biomass in corn and soybean was low (≤4.2 g m−2) in all systems. Experimentally supplemented giant foxtail (Setaria faberi Herrm.) seed densities in the surface 20 cm of soil declined in all systems; supplemented velvetleaf (Abutilon theophrasti Medik.) seed densities declined in the 2- and 4-yr systems and remained unchanged in the 3-yr system. Without subsidy payments, net returns were highest for the 4-yr system ($540 ha−1 yr−1), lowest for the 3-yr system ($475 ha−1 yr−1), and intermediate for the 2-yr system ($504 ha−1 yr−1). With subsidies, differences among systems in net returns were smaller, as subsidies favored the 2-yr system, but rank order of the systems was maintained

Calibration of Traffic Simulation Models using SPSA

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Γεωπληροφορική

The financialization of the non‐financial corporation. A critique to the financial turn of accumulation hypothesis

One aspect in which non-financial corporations (NFCs) are said to be financialized is that they have been increasingly engaged in financial accumulation from which they derive a growing proportion of financial income. This is what we call the financial turn of accumulation hypothesis. In this article, we show that the evidence used to sustain it, in the U.S. setting, has to be reconsidered. Our findings show that, contrary to the financial turn of accumulation hypothesis, financial income averages 2.5% of NFCs’ total income since the 1980s, oscillating since the beginnings of the 1990s until 2005 and then declining. In terms of assets, some of the alleged financial assets might actually reflect other activities in which NFCs have been increasingly engaged, such as tax avoidance, internationalization of production, activities refocusing and M&As

Prisoners of the Capitalist Machine: Captivity and the Corporate Engineer

This chapter will focus on how engineering practice is conditioned by an economic system which promotes production for profit and economic growth as an end in itself. As such it will focus on the notion of the captivity of engineering which emanates from features of the economic system. By drawing on Critical Realism and a Marxist literature, and by focusing on the issues of safety and sustainability (in particular the issue of climate change), it will examine the extent to which disasters and workplace accidents result from the economic imperative for profitable production and how efforts by engineers to address climate change are undermined by an on-going commitment to growth. It will conclude by arguing that the structural constraints on engineering practice require new approaches to teaching engineers about ethics and social responsibility. It will argue that Critical Realism offers a framework for the teaching of engineering ethics which would pay proper attention to the structural context of engineers work without eliminating the possibility of engineers working for radical change

Beyond flows, fluids and networks: Social theory and the fetishism of the global informational economy

In this paper we critically explore some of the arguments made by those social theorists who claim that we live in a new global economy defined by informational and technological flows, fluids and networks. By recourse to Marx's concept of fetishism we argue that these theorists often fetishise the very social changes in the global economy they are trying to describe. As a result, they articulate a ‘flat ontology’ of concrete and contingent relations that mistakenly claims to capture the most important dynamics of global capitalism. We reject this approach, preferring instead to see global capitalism as a dialectical flux between concrete and more abstract processes. These critical points are developed by drawing on Marxism to explore how these social theorists often reproduce unhelpful dualisms in social theory, how they fetishise technology, how some of their arguments run parallel to a management justification logic of the market world and finally how they present a limited explanation of global finance