Non-inversion tillage in organic arable cropping

The opportunities for using an non-inversion tillage (NI) approach in organic systems has not been well investigated by research and what research has been done has not perhaps been sufficiently long-term. The benefits of the system in terms of the economics of establishment and the improvement in soil quality make the system attractive, but it is a system that will take some time to get established and is one that will require the farmer to “hold his nerve” as grass weed, perennial weed burdens and slug predation may increase in the early years of implementation. In conventional systems and the POB work yields have reported to drop when implementing an NI system. This is before some of the benefits of a better quality soil are seen, but in the work done by Dr Michael Brandt in an organic system no yield drop was experienced. This was also the case for Danish work done by Per Schonning. Phosphate (P) and Nitrate (N) losses can be reduced as soil structure improves and becomes more stable. Better water ingress into the soil will reduce run-off and sediment and P loss and better water retention in the soil structure will reduce leaching potential. This is perhaps particularly the case at the time that the ley phase of a rotation is broken when greatest risks of N leaching occurs particularly if this coincides with significant rainfall

Getaway Special competition: Overview

Recommendations submitted for experiments to be conducted onboard the space shuttle are presented. Short biographies of the finalists in the Get Away Special (GAS) competition were included

A CANDELS WFC3 Grism Study of Emission-Line Galaxies at z ~ 2: A Mix of Nuclear Activity and Low-Metallicity Star Formation

We present Hubble Space Telescope Wide Field Camera 3 (WFC3) slitless grism spectroscopy of 28 emission-line galaxies at z ~ 2, in the GOODS-S region of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. The high sensitivity of these grism observations, with >1σ detections of emission lines to f > 2.5 × 10^(–18) erg s^(–1) cm^(–2), means that the galaxies in the sample are typically ~7 times less massive (median M_* = 10^(9.5) M_☉) than previously studied z ~ 2 emission-line galaxies. Despite their lower mass, the galaxies have [O III]/Hβ ratios which are very similar to previously studied z ~ 2 galaxies and much higher than the typical emission-line ratios of local galaxies. The WFC3 grism allows for unique studies of spatial gradients in emission lines, and we stack the two-dimensional spectra of the galaxies for this purpose. In the stacked data the [O III] emission line is more spatially concentrated than the Hβ emission line with 98.1% confidence. We additionally stack the X-ray data (all sources are individually undetected), and find that the average L_([O III])/L_(0.5-10keV) ratio is intermediate between typical z ~ 0 obscured active galaxies and star-forming galaxies. Together the compactness of the stacked [O III] spatial profile and the stacked X-ray data suggest that at least some of these low-mass, low-metallicity galaxies harbor weak active galactic nuclei

Black South African short fiction in English since 1976

African Studies Seminar series. Paper presented 18 August 1986The students' uprising of 1976 hardly features in stories by black South African writers. In this respect, the short story is noticeably different from novels, plays and poems by black writers in which these events are often given central place. Short fiction, one should indicate, has been a predominant genre in the black community since the 1950's. What one sees happening after 1976 is not so much, a new direction for this genre, but a flowering of new works in the form. That is, the major collections of black short fiction since 1975 have not offered any major break with foregoing traditions in the form, as most certainly seems the case with the novel, but have continued the exploration of themes and concerns central to earlier collections of black short stories: what is different is the emefeence of new writers in the form. In this essay, I shall examine the key elements of black South African short fiction in English since 1976, touching upon connections not only with earlier collections of black short fiction but also with short fiction by white South African writers