Site Specific Management: The Pros, the Cons, and the Realities

Site specific management (SSM) for agriculture involves the variable management of soils and crops according to localized conditions within a field. Known by many other names, such as Grid Farming , Farming by Soils or Variable Rate Technology (VRT), SSM is a rapidly emerging set of technologies that allow farmers to manage their soils and crops on-the-go as equipment moves across a field. In essence, SSM is about doing the right thing, at the right time, in the right place, in the right way. Thus, SSM is intuitively appealing because it represents a means of improving the economic and environmental performance of cropping systems. However, while proponents of SSM will endorse its great potential, the fact is that SSM is an emerging technology that is best described as still in its infancy. Thus, at this stage in its development, SSM has its strengths (Pros) and its weaknesses (Cons) which in combination clearly define the current status of SSM for agriculture (Realities). What follows is a brief overview describing some essential elements of SSM and the degree to which these elements have or have not been developed

Site-selective ion beam synthesis and optical properties of individual CdSe nanocrystal quantum dots in a SiO2 matrix

Cadmium selenide nanocrystal quantum dots (NC-QDs) are site-selectively synthesized by sequential ion beam implantation of selenium and cadmium ions in a SiO2 matrix through sub-micron apertures followed by a rapid thermal annealing step. The size, areal density and optical emission energy of the NC-QDs are controlled by the ion fluence during implantation and the diameter of implantation aperture. For low fluences and small apertures the emission of these optically active emitters is blue-shifted compared to that of the bulk material by $>100\,{\rm meV}$ due to quantum confinement. The emission exhibits spectral diffusion and blinking on a second timescales as established also for solution synthesized NC-QDs