The use of synthetic nano-particles (NPs) in plant protection substances and fertilisers can bring with it advantages for the environment. On the one hand, NPs can be used as vehicles for active substances, and on the other they can act as reduction-oxidation catalysts. This enables the quantity of active substances to be reduced and thus decreases the burden on the environment. Before nano-materials can be used in such substances, however, the potential risks need to be studied. In this connection, it should be emphasised that the chemico-physical properties of synthetic NPs are dependent on their size, form or surface chacteristics. Little is known as yet concerning the uptake of NPs in crops and their redistribution in the environment, and it is therefore not possible to make general predictions in this respect. To date there exist almost no analytical methods for quantifying NPs in environmental samples. For these reasons scientific projects need to be set up to determine the uptake of NPs in plants and their subsequent redistribution. It is only through such projects that we shall find an answer to the question of whether residues of NPs remain and, if so, whether they represent a hazard for man. We also need to better understand how NPs affect the environment before their use in agriculture is authorised. The relevant authorities and research teams should provide information as to the safe use of nano-technology so that nano-particles can be used in agriculture in a productive and sustainable way.
Symbiotic nitrogen fixation by bacteria in the soil coexisting with legumes leads to reduced fertiliser requirement. It is not easy to measure this variable on farms, however. Now researchers from Agroscope have developed a method for estimating nitrogen input via symbiotic fixation at farm level.
With increasing global and regional temperatures, even in Switzerland the growing season has lengthened considerably. Using data from the Federal Office of Meteorology and Climatology, Agroscope has traced the development of the growing season since the start of the previous century.
The phosphate mineral reserves required for fertiliser production could be exhausted on a global scale in just a few decades. This study presents a method for recycling a Swiss industrial by-product into a phosphate fertiliser.